Late Cretaceous elasmobranch palaeoecology in NW Europe

Palaeogeography, Palaeoclimatology, Palaeoecology 388 (2013) 23–41

Contents lists available at ScienceDirect

Palaeogeography, Palaeoclimatology, Palaeoecology

j ourna l homepage: www.e lsev ie r .com/ locate /pa laeo

Late Cretaceous elasmobranch palaeoecology in NW Europe

Guillaume Guinot ⁎School of Earth and Planetary Sciences, Birkbeck College, Malet Street, London WC1E 7HX, United KingdomInstitut des Sciences de l'Evolution de Montpellier, UMR5554, Université Montpellier 2, cc 064, Place Eugène Bataillon, 34095 Montpellier Cedex 5, France

⁎ Department of Geology and Palaeontology, Natural HiMalagnou 1, CP 6434, CH-1211 Geneva 6, Switzerland. Te

E-mail address: [email protected].

0031-0182/$ – see front matter © 2013 Elsevier B.V. All rihttp://dx.doi.org/10.1016/j.palaeo.2013.07.027

a b s t r a c t
a r t i c l e i n f o
Article history:Received 7 May 2013Received in revised form 19 July 2013Accepted 24 July 2013Available online 30 July 2013

Keywords:ElasmobranchsPalaeoecologyMarine palaeoenvironmentsPalaeobiogeographyLate CretaceousPhosphatic chalksNW Europe

Late Cretaceous elasmobranch faunas are known fromnumerous of NWEurope localities but their palaeoecologicalcharacteristics are still poorly known. Recent studies on Anglo-Paris Basin elasmobranch faunas from phosphaticchalks provided detailed data on the taxonomic composition of these communities. Results based onmultiproxyanalyses suggest peculiar conditions for Cenomanian faunas with numerous lamniforms and rare nectobenthictaxa indicative of dysoxic conditions. Changes in Turonian faunal composition correlate with a maximumin palaeotemperatures and transgressive environmental conditions. The northern Coniacian glauconiticpalaeoenvironment provided cooler and shallow environments suitable for a few species with probable migra-tion patterns. A model is proposed to explain the ecological features of the Santonian–Campanian faunas inwhich the habitat heterogeneity is the main factor controlling elasmobranch diversity and evenness. The domi-nance of small-sized species in Santonian–Campanian faunas is similar to the patterns observed in modern up-welling environments. Low beta diversity of early Campanian faunas suggests that although faunas were fromdisjunct upwelling erosional channels, the number of such palaeoenvironments provided a wide range of habi-tats allowing species to migrate depending on local ecological conditions. The Santonian/Campanian globalcooling is synchronouswith changes in faunal compositions. Larger-scale palaeoecological, palaeoenvironmentaland palaeogeographical patterns are proposed based on comparisons with a number of other NW Europe elas-mobranch faunas.

© 2013 Elsevier B.V. All rights reserved.

1. Introduction

Late Cretaceous elasmobranch remains have been collected from NWEurope since thefirst half of the 19th century (e.g.,Mantell, 1822; Agassiz,1843) and regularly aroused interest of palaeoichthyologists untilpresent-day (e.g., Sauvage, 1870; Priem, 1908; Woodward, 1911, 1912;Leriche, 1929; Dalinkevičius, 1935; Herman, 1977; Underwood andMitchell, 1999; Vullo, 2005; Guinot et al., 2013). Yet, although thesedecades of work have considerably improved the knowledge on elasmo-branch taxonomy and diversity, little is known on palaeoecological char-acteristics of Late Cretaceous elasmobranch communities and, to a greaterextent, of fossil elasmobranch assemblages. Recently however, a fewstudies described specific relationships between elasmobranch taxa andsedimentary facies (Underwood, 2004) or used statistical tools to investi-gate palaeoecological and palaeogeographical patterns in Mesozoic andCenozoic elasmobranch faunas (Adnet, 2000; Vullo, 2007). These alsoemphasised issues faced in the identification of palaeoecological patternsdue to the nature of elasmobranch fossil remains (consisting of isolatedteeth only thus making impossible documentation on body size andexact number of individuals), biological mixing, time-averaging, andimperfect knowledge on modern elasmobranch faunas.

storyMuseum of Geneva, Rte del.: +41 2 24 18 63 22.

ghts reserved.

A recent series of papers (Underwood andWard, 2008; Guinot et al.,2012a,b, 2013) described the detailed composition of numerous fossilelasmobranch assemblages from the Late Cretaceous Anglo-Paris Basinchalks, including precise stratigraphic origins, sedimentary setting andspecimen counts. The resulting data offer a wide range of possibilitiesfor the study of palaeoecological parameters that control the structureof fossil marine vertebrate assemblages in the peculiar phosphaticchalk palaeoenvironments. Here, palaeoecological characteristics ofthese elasmobranch communities are identified using univariate andmultivariate analyses based on taxonomic characteristics, diversitymeasurements and qualitative observations. These features are corre-lated with palaeoenvironmental factors with the aim of identifyingcausal mechanisms of the variations in faunal structure and migrationpatterns along with palaeoecological specificities for some taxa atlocal and regional scales. The degree of similarity between these faunasand other published assemblages from NW Europe are assessed inorder to identify larger-scale palaeoecological, palaeoenvironmentaland palaeogeographical patterns.

2. Material and methods

2.1. Material

The material studied here encompasses 22 elasmobranch assem-blages (see Guinot et al., 2012a, 2013 and Supplementary Material 1

http://crossmark.dyndns.org/dialog/?doi=10.1016/j.palaeo.2013.07.027&domain=f

http://dx.doi.org/10.1016/j.palaeo.2013.07.027

mailto:[email protected]


http://www.sciencedirect.com/science/journal/00310182

24 G. Guinot / Palaeogeography, Palaeoclimatology, Palaeoecology 388 (2013) 23–41

for more details on sampled sites) sampled from Cenomanian toCamypanian horizons from the Anglo-Paris Basin (northern France,southern England) and Northern Ireland (Underwood and Ward,2008; Guinot et al., 2012a, 2012b, 2013). This allowed a species-level database, including abundance data (number of fossil remainsper species) and accurate stratigraphic ages (biozones), to be built.With the exception of the Northern Ireland fauna (glauconitic sand-stones), all assemblages were bulk-sampled from ‘phosphatic chalks’associatedwith hardgrounds or basal lag accumulations. The ‘phosphat-ic chalks’ can be divided into two types: (1) phosphatised lithifiedchalks corresponding to planar structures that often reach several tensof centimetres to rarely 1 m thick and that form the top surface ofmany hardgrounds or omission surfaces, often associated withThalassinoides burrow systems; and (2) phosphatic chalks (sensuJarvis, 1980a) deposited within isolated troughs (‘cuvettes’) up to1 km in length, 250 m in width and 30 m deep from late Coniacianto early Campanian in northern France and southern England. Thebottom of these ‘cuvettes’ is always composed of basal hardgroundcomplexes that are lithified beds displaying multiple mineralizedsurfaces and various Thalassinoides burrow systems. On top of thesehardgrounds, between the hardground and the fossil-rich phosphaticchalk, rests another very fossil-rich horizon containing both vertebrateand invertebrate remains referred to as the basal lag accumulation(Jarvis, 1980a). The phosphatic chalk that rests on top of the basal lagaccumulation can reach several tens ofmetres thus indicating that the en-vironmental conditions leading to these deposits were continuous over aprolonged time period. The nature of the Cenomanian fossil-rich depositsincluded here differs as it comprises marine channels that cut down theunderlying strata (marl–limestone alternations). These channels are part-ly infilled with nodular phosphate-rich accumulations. The bottom of thechannel-fill commonly consists of a burrowed and encrusted surface, andthe body of the channel is mainly composed of coarse-grained nodularchalk, phosphatized pebbles and coprolites, worm burrows, and inverte-brate and vertebrate remains. The depth at which the phosphatic chalksdeposited is not precisely assessed but different indications can benoted. In his study of belemnites from the phosphatic chalks Jarvis(1980a) noted the presence of juveniles in the faunas recovered,suggesting a near-shore and therefore a shallow-water environment forthese facies. Jarvis (2006), on the basis of the absence of benthic algal re-mains, lack of macrophytic structures on the attachment areas of macro-phytic encrusters, and the presence of marine phreatic cements only,considered that phosphatic chalk deposition occurred below the photiczone (i.e. below 70 to 100 m). However, judging from the presence ofmuddy sediments and nature of the invertebrate faunas, Cenomanian de-posits represent a time of relatively shallow water across much of theAnglo-Paris Basin (Gale et al., 2000).

Data from NW Europe were gathered from the literature. Only rela-tively recently published faunas were considered in order to minimisethe bias thatwould be caused by the under-representation of smallmate-rial in older literature. Over the past decades, such studies have provided28 shark assemblages all included in the present analysis. These compriseCenomanian–Campanian elasmobranch assemblages from England(Underwood and Mitchell, 1999), western France (Landemaine, 1991;Vullo, 2005; Vullo et al., 2007), Belgium and north-eastern France(Herman, 1977) and Germany (Müller, 1989; Müller and Diedrich,1991; Hübner and Müller, 2010) as well as data from the Anglo-ParisBasin. The 50 faunas were arranged into a matrix including the numberof species per genera, so as tomaintain details on the taxonomic structureof each elasmobranch assemblage, despite the generic-based data. Detailson the data used in the analyses are given in Supplementary Material 1.

2.2. Methods

Several diversity indices take account of the effect of dominance (orits inverse, the evenness). This is based on species abundance and tendsto give higher diversity values to assemblages with an equal number of

specimens per species (high evenness, low dominance) than toassemblages with one species representing most of the specimens(low evenness, high dominance). Among them, the Simpson indexof dominance D = ∑ (pi2), where pi = ni / n (the proportion ofspecies i); 1-D being the Simpson index of diversity indicates theprobability that two randomly-selected individuals are of the samespecies (Hammer and Harper, 2006), whereas the equitability (J)computes an index of evenness normalised for sample size. TheShannon–Wiener index (H′) is a measure of the average degree ofuncertainty in predicting to which species an individual randomlypicked will belong. The average uncertainty increases as the numberof species increases and as the distribution of individuals among thespecies becomes even. The Fisher's α assumes that the abundance ofspecies follows the log series distribution and takes into account thenumber of taxa and the number of individuals. Because each indextends to stress different aspects of the fauna's composition, theyare used in combination here.

Taxonomic distinctness is another tool for estimating the biodiversi-ty of an assemblage butwith the addition of a bio-complexity parameterbecause the taxonomic structure of the community is taken into account(Warwick and Clarke, 1995, 1998). As a result, communities containinga wide range of higher-level taxa (families, orders) will have a higherdiversity index than communities with the same number of speciesand relative abundances but belonging to a single order. According toWarwick and Clarke (1998), taxonomic distinctness seems relatively in-dependent to sample size. Here, the taxonomic levels comprise species,genera, families and orders. Taxonomic distances are defined betweeneach taxon according to their higher taxonomic affinities, which allowsthe computation of taxonomic diversity. Taxonomic distinctness is thenthe taxonomic diversity divided by the Simpson's index.

Diversity is usually divided into three different elements, dependingon the scale considered (Whittaker, 1960, 1972). The alpha diversityrepresents the species richness of a given community related to agiven habitat, whereas the beta diversity is the variation in taxonomiccomposition of communities among habitat gradients (areas of alphadiversities). The gamma diversity is the taxonomic differentiationacross geographical areas (endemicity) or provinces, often consid-ered as regional diversity. The original measure of beta diversity(Whittaker, 1960) will be used here, with modifications ofHarrison et al. (1992) giving values between 0 and 100 for completesimilarity and complete dissimilarity respectively, and allowing di-rect comparisons between samples of unequal size. The Whittakerequation of beta diversity is: βH1 = γ

α−1� �� 100

N−1ð Þ where N is the

number of sites. Consequently, low beta diversity values indicateweak habitat gradient and heterogeneity as well as low provinciality.Beta diversity analyses were run following Vavrek and Larsson (2010)using the R Statistical Software (R Development Core Team, 2010) withthe package Fossil (Vavrek, 2012).

Individual-based rarefaction (Sanders, 1968) was used here forstandardising species-richness values between assemblages of varyingsample sizes (i.e. assemblages of varying number of fossil remains).

Similaritymatrices and subsequent clustering were computed usingrespectively the vegdist (package Vegan; Oksanen et al., 2010) andhclust (package Stats; R Development Core Team, 2010) functions ofthe R Statistical Software.

3. Results

3.1. Ecological diversity

3.1.1. Taxic richness in elasmobranch communitiesWith the exception of the Echinorhiniformes and Pristiophoriformes,

all fossil and modern elasmobranch orders known from the LateCretaceous are represented in the Anglo-Paris faunas studied here(Fig. 1). Among them, two orders, the Lamniformes (Mackerel sharks)

25G. Guinot / Palaeogeography, Palaeoclimatology, Palaeoecology 388 (2013) 23–41

andCarcharhiniformes (Ground sharks) dominate each faunawithout ex-ception. Together, they represent from46% (Barrington) up to over 70% ofthe species diversity in some assemblages (Mont-Août lower horizon,Villers-devant-le-Thours, Taplow lower horizon, Winterbourne lowerhorizon) and comprise 61% of the average species diversity in the LateCretaceous of the Anglo-Paris Basin. The Orectolobiformes (Carpetsharks) and Rajiformes (skates), along with the Heterodontiformes(Bullhead sharks) and Squatiniformes (Angel sharks), are other or-ders represented in most samples, although not dominating theassemblages.

The species richness per assemblage (alpha diversity) indicatesa marked difference between maximum (N = 40, Barrington) andminimum (N = 16, Faucouzy upper horizon) alpha diversities amongthe faunas considered (Fig. 2), and there is no clear stratigraphic differ-entiation in species richness. However, because samples are very het-erogeneous in size (total number of teeth), comparisons between raw

Fig. 1. Bar chart showing the percentages of species per order for each fauna (in stratigraphic oJustine-Hebigny; MNN: Minnis North; BXD: Boxford; TPL-L: Taplow lower horizon; TPL-UWinterbourne upper horizon; HAL-L: Hallencourt lower horizon; HAL-U: Hallencourt upper hupper horizon; SCP: Stoke Clump; CVR: Culver; DWD-1: Downend 1; DWD-2: Downend 2; MA

species richness values are of low significance. Therefore, individual rar-efaction was performed to compensate for sample size variations andallow comparison of relative estimated species richness between faunas(Fig. 2). In order to include the 22 faunas in the rarefaction analysis, thiswas performed at the sample size of the smallest sample (Mont-Aoûtlower horizon, n = 71, rounded off to n = 70). However, becausethis sample size is extremely small compared to the remaining samples,rarefaction was similarly used with samples sizes of n = 170 and n =310. Although this excludes samples of smaller sizes, it allows confirma-tion of the previously observed trends with more robust sample sizes(but with less complete data). The rarefied species richness indicatesrather high values for pre-Campanian faunas with the exception of theTotternhoe fauna (and possibly Taplow lower), whereas faunas fromJustine-Herbigny and Séru are the richest. Both late Campanian faunasfrom Mont-Août are relatively rich, however, early Campanian speciesrichness seems uneven with faunas from Villers-devant-le-Thours and

rder). Abbreviations: BGN: Barrington, STM: Southerham Grey Pit; TTE: Totternhoe; JUH:: Taplow upper horizon; SRU: Séru; WBN-L: Winterbourne lower horizon; WBN-U:orizon; VRT: Villers-devant-le-Thours; FZY-L: Faucouzy lower horizon; FZY-U: FaucouzyO-L: Mont Août lower horizon; MAO-U: Mont-Août upper horizon.

Fig. 2. Bar chart showing raw species richness per locality and corresponding rarefied species richness using sample sizes of n = 70, n = 170 and n = 310. Vertical bars indicate standarddeviation.

Fig. 3. Diversity indices computed for each fauna.


image of Fig.�2

image of Fig.�3


Faucouzy (lower and upper horizons) having rarefied species richnesscomparable to that of pre-Campanian faunas, whereas assemblagesfromHallencourt, Stoke Clump, Culver and, to a lesser extent Downend,are comparatively less rich.

The rationale to evenness is that the more the species found in anassemblage are present in equal proportions (abundance data), themore diverse the assemblage is. This thus leads to low diversity valuesfor faunas dominated by a few species. Resulting scores of these indicescomputed for the faunas considered here are represented in Fig. 3.Although they do not work out diversity the same way (e.g. the even-ness and equitability indices are normalised for species richness, where-as the Fisher's alpha assumes that the abundances are distributedaccording to a logarithmic abundance model), they all correlate eachother (Supplementary Material 2 for statistical correlation tests) andprovide similar results; differing in some details only. These generallyindicate low diversity (i.e. high dominance) for faunas from Totternhoe,Hallencourt, Stoke Clump, Culver and to a lesser extent, Taplow lowerhorizon and Downend. Interestingly, faunas of lower species richnessvalues are faunas of higher dominance, as suggested by the strong corre-lation between diversity indices and rarefaction values. The percentage ofdental remains per species (SupplementaryMaterial 3) allows the identi-fication of dominant species for each fauna. The Cenomanian fauna fromTotternhoe is dominated by the mitsukurinid Scapanorhynchus minimus,which represents more than half thematerial. This species is also presentbut not dominant in other Cenomanian faunas (although representing28% of the teeth in Southerham). With the exception of the Downendfaunas, all Santonian–early Campanian assemblages showing low even-ness are dominated by a single species, the Carpet shark Chiloscylliumfrequens, representing from 29% up to 75% of the material in some faunas(Taplow upper horizon and Stoke Clump, respectively). Faunas fromHallencourt lower and upper horizons also show a large fraction(24% and 34%, respectively) of remains of a mitsukurinid (Anomotodonhermani) and 17% of remains of the anacoracid Squalicorax kaupi for thelatter fauna,whereas the remaining species are rather poorly represented.In the Downend assemblages however, several species represent over20% of the remains each: S. kaupi, Crassescyliorhinus germanicus andPseudoscyliorhinus reussi for Downend 1 and Squatina (Cretascyllium)hassei and C. germanicus for Downend 2. Although these two faunas(along with that of Villers-devant-le-Thours showing a high proportionof teeth of Palaeogaleus havreensis) show some degree of domi-nance, they are also characterised by a relatively high species rich-ness (particularly Villers-devant-le-Thours), which contrasts withother faunas showing high dominance.

Fig. 4. Values of taxonomic di

3.1.2. Taxonomic distinctnessAlthough palaeoecological diversity analyses provide valuable re-

sults, they do not give information on the taxonomic structure of fossilassemblages. In fact, a given assemblage showing high diversity doesnot necessarily imply a high taxonomic distinctness value, as most oftaxa present may belong to the same taxonomic group. Taxonomic dis-tinctness analyses performed here provide information on the degree ofrepresentation of the various elasmobranch groups among assem-blages. Taxonomic distinctness values for each fauna are illustrated inFig. 4, the average value for the 22 faunas being Δ = 4.6. Totternhoe,Boxford, Séru,Winterbourne (lower and upper horizons) andDownendfaunas have a fairly low taxonomic distinctness whereas those fromBarrington, Hallencourt (lower and upper horizons), Stoke Clump,Culver andMont-Août upper horizon show thehighest values. Althoughthe high taxonomic distinctness of some faunas such as Barrington cor-relates positively with high species richness, negative correlations arealso found. The low diversity faunas marked by a high dominance(such as the Hallencourt faunas, Taplow lower, Stoke Clump and Culverassemblages) show a high taxonomic distinctness; whereas faunascharacterised by low dominance and high diversity (Boxford, Séru, theWinterbourne and Faucouy) have low taxonomic distinctness values.Although faunas of the latter group are diverse, they aremainly composedof various scyliorhinids, triakids and few lamniforms besides the cosmo-politan orectolobiforms (Pararhincodon, Chiloscyllium) and Squatina.Faunas from the first group however, are characterised by taxa belongingto underrepresented groups such as synechodontiforms (Hallencourtupper horizon), Orectolobiformes incert. fam. (Cederstroemia) and para-orthacodontids (Hallencourt, Culver, Stoke Clump), which increase theirtaxonomic distinctness score.

3.1.3. Beta diversity of early Campanian faunasBeta diversity, as defined byWhittaker (1960, 1972), represents the

difference in taxonomic composition across assemblages found invarious areas of alpha diversity. Measures of beta diversity provide indi-cations on the variety of habitats within a region and on the species re-placement between discontinuous units of the same habitat (Harrisonet al., 1992). Therefore, this can be considered as an indicator of faunalturnover across a given region, influenced by the proportion of endemictaxa, which reflects the degree of provinciality. Beta diversity measureshave been used in biodiversity studies on modern terrestrial groups(Harrison et al., 1992; Condit et al., 2002; Novotny et al., 2007), but fossilgroups are little represented (but see Vavrek and Larsson, 2010). A rea-son for this is that such studies require a large dataset from relatively

stinctness for each fauna.

image of Fig.�4

Table 1Results for rarefaction and nonparametric richness estimators for the Early Campanianfaunas. AER: Average Estimated Richness (Mean value of rarefaction, Chao 1, ACEand Jackknife 1).

Localities No. ofspecimens

Speciesrichness

Rarefaction Chao 1 ACE Jackknife 1 AER

WBN-U 349 26 17.72 28.48 20.6 23.95 22.68HAL-L 10,219 19 8.41 13.66 11.75 11.76 11.4HAL-U 6389 22 7.89 12.2 14.2 10.84 11.3VLT 1070 30 15.29 28.99 19.2 21.94 21.36FZY-L 175 28 20.14 40.53 25.33 29.5 28.88FZY-U 84 16 16 16.67 16.54 17.98 16.8SCP 1776 22 912 15.02 11.96 12.82 12.23CVR 5376 32 12.27 20.64 15.13 17.14 16.29DWD 3461 33 13.21 25.23 19.52 18.83 19.2DWD 2 740 26 15.42 26.67 18.52 21.38 20.5γ diversity 29,639 54 13.77 24.98 16.58 19.23 18.64Average α – 25.4 13.56 22.81 17.28 18.61 18.06βH1 – 12.51 0.18 1.06 −0.45 0.37 0.35


restricted geographical areas and time intervals, in order to maintainecologically significant results. Accordingly, the ten early Campanian as-semblages sampled from seven localities in northern France and south-ern England were selected for the beta diversity analysis because theyrepresent a reasonable dataset from a relatively restricted period oftime. Elasmobranchs are mobile animals and the faunas consideredare relatively geographically close to each other. However, these assem-blages were sampled from disjunct fossil-rich phosphatic horizons, iso-lated from one another by large areas of fossil-poor white chalk.Following Vavrek and Larsson (2010), the degree of provincialityamong early Campanian elasmobranch faunas from the Anglo-ParisBasin was assessed. Results based on observed species richness valuesand average richness for all early Campanian faunas (αavge = 25.4), in-dicate relatively high beta diversity values (βH1 = 12.51, see Table 1).However, the difference in size between the various samples consideredhere is substantial, from n = 84 (Faucouzy upper) to n = 10,219(Hallencourt lower), thus lowering the alpha diversity of small-sizedsamples and increasing beta diversity score (see Novotny et al., 2007).Rarefaction standardised to the lowest sample size (Faucouzy upper)and non-parametric estimators were used in order to compensate forthis sample size heterogeneity (Supplementary Material 4). Resultingaverage alpha diversity (αavge = 13.56) values were much lowerwhereas gamma diversity is nearly four times lower thanwith observeddata. Although the results provided by the rarefaction and estimatorsdiffer from one another, values of gamma and alpha diversities are

Fig. 5. Analysis of provinciality among Early Campanian Anglo-Paris faunas. A, MST showing thB, Pairwise dissimilarity (Sorenson distance index) between sites relatively to their geographic

very similar for a givenmethod. Although resulting beta diversity valuesdo not have a direct ecological meaning, the very similar gamma andalpha values indicate that there is very little turnover between fossilsites and no real ecologically significant differences between assem-blages. In addition, a minimal spanning tree (MST) was computed(using the Sorenson distance measure) and plotted onto a geographicspace (Fig. 5A) in order to visualise groupings. No apparent clustersstand out as geographically remote assemblages showmore similaritiesthan they dowithmore closely-situated assemblages (e.g. see Faucouzyupper and Winterbourne upper relatively to Villers-devant-le-Thours).Similarly, pairwise dissimilarities between early Campanian sites rela-tively to their geographical distance (Fig. 5B) show that similarity in tax-onomic composition of the different assemblages is poorly associatedwith geographic distance. Although the sites show a very slight increasein dissimilarity over geographic distance (linear regression), this is notsignificantly different from zero. Rarefaction, species estimators, MSTand pairwise similarity all indicate low beta diversity for the early Cam-panian elasmobranch assemblages.

3.2. Distribution of modes of life

Marine fishes, and particularly elasmobranchs, have developed dif-ferent modes of life and occupy all ecological niches within the watercolumn. The latter is typically divided into different zones, from thesurface to the sea floor, to which species show different adaptations.Pelagic fishes live within the water column and are active swimmers(nektonic fishes) or planktonic and generally move long distances.The nectobenthic (or demersal) mode of life includes species that livein the lower part of the water column and is usually divided intobenthopelagic (above the bottom) and benthic (on the sea floor), withthe latter species often resting on — or buried into — the sea floor anddeveloping ambush feeding strategies (e.g. Angel sharks). However,these groups of modes of life are not exclusive as some benthic elasmo-branchs are not restricted to the sea floor and can swim in the lowerpart of the water column. For instance, taxa that feed on benthic immo-bile preys tend to be highly mobile themselves (e.g. Eagle rays such asAetobatus and probably the extinct shark Ptychodus). In addition, the in-formation needed to address the mode of life of modern elasmobranchspecies requires data on their behaviour, which can be difficult to ob-tain. When fossil taxa are considered, such direct information is notavailable and although some Cretaceous genera have modern relatives(Squatina, Carcharias), most of them are not represented in modernfaunas. However, many modern elasmobranch families with fossil rep-resentatives encompass taxa of similar modes of life. For instance,

e relative pairwise similarities between Early Campanian localities, plotted on geography.distance from one another.

image of Fig.�5


modern scyliorhinids, orectolobids, squatinids, heterodontids andtriakids are mainly nectobenthic whereas modern lamnids are mainlypelagic. Additionally, post-cranial skeletal remains (mainly fromLebanon, see Cappetta, 1980a,b) and tooth morphologies of fossil spe-cies can help identify their mode of life. Consequently, the mode of lifeof the fossil species considered here has been identified but restrictedto two groups referred to as pelagic and nectobenthic (benthic andbenthopelagic), others were left undetermined. Percentages of speciesper mode of life (Fig. 6A) indicate that the vast majority of Late Creta-ceous faunas from the Anglo-Paris Basin is dominated by nectobenthicspecies, representing from 60% up to over 80% of the species. Only themiddle Cenomanian faunas of Southerham and Totternhoe have amajority of pelagic species (62% and 74%, respectively). Among post-Cenomanian faunas the two minor troughs in the proportion ofnectobenthic species correspond to theHallencourt upper and Faucouzylower faunas. Although the latter may be due to the small size of thesample (n = 175), the former corresponds to the highest proportion(40.9%) of pelagic species (such as Squalicorax kaupi and Anomotodonhermani) among post-Cenomanian faunas, although not considerablydifferent from the others. Data on abundance of fossil remains permode of life (Fig. 6B) indicate a similar distribution for Cenomanianfaunas with a high number of teeth belonging to nectobenthic speciesin the early Cenomanian fauna of Barrington whereas these are minorcomponents of the middle Cenomanian faunas (less than 8% inTotternhoe). The Turonian fauna of Justine-Herbigny shows nearly sim-ilar proportion of both modes of life and the Coniacian fauna of MinnisNorth is dominated by dental remains of pelagic taxa. Similar to number

Fig. 6. A, Variation of the percentage of nectobenthic (black line) species among the Anglo-Papercentage of teeth belonging to nectobenthic (black line) species among the Anglo-Paris Basi

of species data, Santonian and Campanian faunas are by far dominated bydental remains of nectobenthic species, which commonly represent from70% up to 96% of the fossils. Faunas fromHallencourt and Downend how-ever, show a high proportion of remains corresponding to pelagic species,which are dominant in Hallencourt upper horizon.

3.3. Cluster analyses

3.3.1. Anglo-Paris Basin faunasThe cluster analysis computed on incidence-based (presence/

absence) data, with the aim of pointing out groups on the basis of thegeneral composition of the assemblages, indicates three main groups(Fig. 7A). The first cluster (I) is represented by the Cenomanian,Coniacian and Turonian faunas, well separated from the Santonianand Campanian assemblages, which make up the second main cluster.The latter is divided into two clusters, one (III) represented by the lateCampanian faunas and the other (II) composed of the intermingledSantonian and early Campanian faunas, which show neither a strati-graphic nor a geographic grouping pattern. In addition, similaritybetween these assemblages does not seem to be mainly related tosedimentary facies as for example, faunas from Hallencourt lower andupper horizons and Stoke Clump (respectively sampled from calcarenitic,peloidal and soft pelletal phosphatic horizons) are grouped together.When abundance data are considered, the shape of resulting den-drograms differs owing to the sensitiveness of the different indicesto the abundances and variable sample sizes. Consequently, Chaoet al. (2005) developed a probability-based Jaccard-type index that

ris Basin faunas (percentage of pelagic species = 100-nectobenthic); B, variation of then faunas. Faunas are in stratigraphic order.

image of Fig.�6

Fig. 7.Cluster analysis of the 22 Late CretaceousAnglo-Paris Basin faunas. A, Dendrogrambasedon incidence (presence/absence) data, using the Jaccarddissimilarity index (similar dendrogramswere obtained with the Bray–Curtis, Canberra and Horn indices) and average linkage clustering method. B, Dendrogram based on abundance data, using the Chao dissimilarity index andcomplete linkage clustering method. Colours refer to stages or substages. Dark blue: Early Cenomanian; light blue: Middle Cenomanian; grey: Turonian; green: Coniacian; purple: Santonian;red: Early Campanian; orange: Late Campanian.


reduces undersampling bias by estimating and compensating for theeffect of unseen, shared species (the greater the frequencies of rare,shared species observed in one of the two assemblages, the moreprobable it is that additional shared species are present in bothassemblages, but absent from one or both samples). The resultingdendrogram provided by this similarity index indicates threeclusters, roughly similar to that based on incidence data (Fig. 7B).As with binary data, cluster II comprises Santonian and earlyCampanian faunas but there seems to be a rather marked stratigraphicpattern within the clustering, with one cluster grouping four out of thefive Santonian faunas, but including the early Campanian fauna ofDownend 1. Conversely, the middle Santonian fauna of Boxford is placednear the base of the cluster including the remaining early Campanianfaunas.

3.3.2. North-western Europe faunasThe data from the Anglo-Paris Basinwere combinedwith other pub-

lished faunas from north-western Europe with the aim of identifyinggeneral ecological and geographical groups at a larger scale and observehow the Anglo-Paris Basin faunas are placed within these groups. Thedendrogram based on data on abundance of species per genus (Fig. 8)indicates three main clusters. Cluster (I) includes the Cenomanianfaunas of Speeton (NE England) whereas the second main cluster (II)encompasses the Cenomanian, Turonian and Coniacian faunas distrib-uted into three sub-clusters. Cenomanian faunas from western France

are all grouped into cluster II-1, separated from the remaining assem-blages. The latter are divided into cluster II-2,which includes Cenomanianto ‘Santonian’ faunas of Belgium and northern France and cluster II-3represented by Cenomanian and Coniacian faunas of Great Britain andGermany. The last main cluster (III) groups together all Santonian andCampanian faunas as well as the Turonian assemblage of Justine-Herbigny. Campanian faunas of Germany and western France are includ-ed into two distinct sub-clusters (III-1 and III-2, respectively) and assem-blages from the Anglo-Franco-Belgian Basin are represented in clusterIII-3. The grouping of two faunas seems somewhat problematic. TheSantonian fauna from theGlauconie de Lonzée (Belgium) is placedwithinthe cluster II-2 whereas other Santonian faunas belong to cluster III-3.Nevertheless, Herman's (1977) study on thematerial from the Glauconiede Lonzée was based on museum collections acquired from dona-tions, purchases or samplings during the late 18th/early 19th century(Herman, 1977, p. 313). In addition to remarks made on the absence ofsmall material due to the size of the meshes used (not less than 2 mmwide), Herman also noted that the elasmobranch remains come fromtwo fossil-rich horizons (likely to be late Coniacian and early Santonianin age) in the Glauconie de Lonzée, and that it was not always possibleto distinguish which horizons the fossils came from. Therefore, aConiacian/Santonian age should be preferred for this fauna. The secondsomewhat surprising position in the dendrogram is that of the middleTuronian fauna of Justine-Herbigny (grouped with Santonian andCampanian faunas in cluster III-3). As mentioned in Guinot (2013), an

image of Fig.�7


elasmobranch-rich horizon equivalent to that of Bettrechies (NWFrance)described byHerman (1977) has yielded a large amount of smallmaterialsimilar to that recorded in Justine-Herbigny but not reported by (Herman,

1977). Similarly, the resampling and fine sieving of sampled fromHerman's (1977) Craie d'Obourg (Belgium) revealed a large number ofsmall dental remains similar to those found in the Mont-Août faunas(H. Cappetta pers. com.) but not documented previously. It is thus proba-ble that Justine-Herbigny andMont-Août faunas aremore closely-relatedrespectively to those from Bettrechies and Craie d'Obourg than indicatedhere by the cluster analyses.

4. Discussion

Variations in faunal composition and relationships with environ-mental parameters of the 22 Anglo-Paris faunas are discussed here inthe first couple of sections (Sections 4.1 and 4.2). Because ordinationanalyses performed here indicate a grouping for the Cenomanian(Barrington, Southerham Grey Pit and Totterhnoe), Turonian (Justine-Herbigny) and Coniacian (Minnis North) faunas, these will be treatedtogether in the first Section (4.1). The second grouping includes thevast majority of samples considered in this work, collected fromSantonian (Boxford, Taplow, Séru and Winterbourne lower horizon),early Campanian (Winterbourne upper horizon, Hallencourt, Villers-devant-le-Thours, Faucourzy, Stoke Clump, Culver and Downend) andlate Campanian sites (Mont-Août). Although the corresponding 17elasmobranch assemblages were all sampled from phosphatic chalkhorizons, the various differences and similarities between these faunas,the variations in sedimentary facies and other palaeoenvironmentalparameters allowed palaeoecological interpretations to be made(Section 4.2). The last section (Section 4.3) comments on the globaldistribution of NW Europe elasmobranchs with comments on generalpalaeoecological and palaeobiogeographical patterns.

4.1. The Cenomanian–Coniacian faunas

4.1.1. The Cenomanian faunasThe three Cenomanian faunas considered here show similarities in

both their faunal content (only three species present in the middleCenomanian faunas are not present in the early Cenomanian ofBarrington) and depositional environments (debris-flows). These faunasshare many species of lamniforms (ten species) as well as numerousnectobenthic taxa (synechodontiforms, hexanchiforms, squaliforms andsquatiniforms). However, they differ in many aspects. First, the middleCenomanian faunas (Southerham Grey Pit and particularly Totternhoe)are dominated by a higher proportion of species — and teeth belongingto species — of pelagic mode of life, which contrasts with the earlyCampanian assemblages of Barrington, dominated by nectobenthic taxa.Similarly, the Barrington assemblage differs from the others by a higherspecies richness and taxonomic distinctness. As discussed in Guinot

Fig. 8. Dendrogram based on abundance data (number of species per genus) on faunasfrom NW Europe, using the Jaccard dissimilarity index and average linkage clusteringmethod. Colours refer to stages; blue: Cenomanian; grey: Turonian; green: Coniacian;purple: Santonian; red: Campanian. Abbreviations: AMA: l'Amas, L. Cenomanian (Vulloet al., 2007); APS: A. plenusmarls, Cenomanian/Turonian (Herman, 1977); ASC: Ascheloh,E.-M. Cenomanian (Müller and Diedrich, 1991); BEC: Beckumer beds, L. Campanian (Müller,1989; Hübner and Müller, 2010); BET: Bettrechies, M. Turonian (Herman, 1977); BIL:Billerbeck, L. Campanian (Müller, 1989); CHB: Chabonne; E. Cenomanian (Landemaine,1991); CLD: Le Caillaud, L. Campanian (Vullo, 2005); FBN: Font-de-Benon, E. Cenomanian(Vullo et al., 2007) FVN; Fouras-Vauban, E. Cenomanian (Vullo et al., 2007); ILA: I. labiatusmarls, E. Turonian (Herman, 1977); LUS: Lussant, E. Cenomanian (Landemaine, 1991); LZE:glauconie de Lonzée, Coniacian/Santonian (Herman, 1977); MAI: Maisières, E. Coniacian(Herman, 1977); MBS: assise à M. breviporus, L. Turonian (Herman, 1977); MCH: Moulinde la Chaussée, M. Cenomanian (Landemaine, 1991); MSH: Meschers, L. Campanian (Vullo,2005); MSR: Montignies-sur-Roc, E. Cenomanian (Herman, 1977); MTG: Montagnan,E. Cenomanian (Vullo et al., 2007); OBG: Craie d'Obourg, L. Campanian (Herman, 1977);PIL: Le Pilou, L. Campanian (Vullo, 2005); RND: Les Renardières, E. Cenomanian (Vulloet al., 2007); SPE1: Speeton 1, M. Cenomanian (Underwood and Mitchell, 1999); SPE2:Speeton 2, L. Cenomanian (Underwood and Mitchell, 1999); STR: Stromberger beds, lateE. Campanian (Müller, 1989; Hübner and Müller, 2010); TLM: Traslemaine, E. Cenomanian(Vullo et al., 2007); TOU: Tourtia de Tournai, Cenomanian (Herman, 1977); TRI: Craie deTrivières, E. Campanian (Herman, 1977).

image of Fig.�8


(2013), the scarcity of species and remains of species of nectobenthicmode of life is very probably due to the hostile nature of bottom watersduring the middle Cenomanian. However, the origin of this unfavourableseafloor environment is difficult to assess because of the nature of thesediment (debris-flow), but dysoxic conditions of the bottom waters isconceivable. This implied a decrease in bottom dwelling taxa with nopossibility of turnover or niche replacement, thus decreasing speciesdiversity and variety of elasmobranch groups represented (low taxonom-ic distinctness).

One of the peculiar characteristics of the Cenomanian faunas is thehigh diversity of lamniform species (up to 58% in Totternhoe), even intheBarrington fauna (29%). In their studyonmodern largemarinepred-ator diversity hotspots, Worm et al. (2003) indicate that marine preda-tor diversity peaks at intermediate latitudes and close to prominenttopographic features such as islands, seamounts or shelf break fronts.In addition, they report higher diversity along the shore than towardoffshore. These features are characterised by increased turbulence,mixing and eddies (Worm et al., 2003). In the Anglo-Paris Basin,early–middle Cenomanian sediments are represented by chalks with ahigh clay content alternating with clay-rich beds indicative of relativelyshallow waters (Gale et al., 2000). These authors proposed a model inwhich this relative shallow shelf sea allowed effective tide and wavemixing along with sufficient nutrient supply through runoff from sur-rounding landmasses. In addition, the presence of a shelf-edge frontwould have maintained the oceanic conditions off the shelf, with purechalk deposition restricted to the continental slope. Thus, such condi-tions (relative shallow andmixedwaters near a shelf break, in interme-diate latitudes) probably provided a suitable environment for thepresence of a diverse community of large apex predators. Modernlamniforms (except plankton-feeders) are active pursuit predatorswith a wide range of prey items, but preferentially feeding on bonyand cartilaginous fishes, cephalopods (squids), marine tetrapods andalso diverse crustaceans (see Compagno et al., 2005). Remains of repre-sentatives of these groupswere found associated to the elasmobranch as-semblages and represent potential preys of the Cenomanian lamniforms.In addition, numerous bony fishes and marine reptile remains were re-ported from the Cenomanian exposure of Machine Bottom Pit nearSoutherham (for a review, see Dineley and Metcalf, 1999).

4.1.2. The Turonian faunaThe most striking feature in the taxic composition of this Turonian

fauna is the absence of representatives of the orders Hexanchiformes(although a hexanchid was recently recovered from JUH — pers. obs.),Synechodontiformes and Squaliformes, whereas these were present inthe Cenomanian faunas, the latter two being represented by anabundant material. This distribution suggests unfavourable environ-mental conditions for these groups in the Turonian compared to theCenomanian. Numerous studies on 18O variations in Cenomanian–Turonian sediments from the Anglo-Paris Basin and other areas (e.g.Jenkyns et al., 1994; Clarke and Jenkyns, 1999; Voigt and Wiese, 2000)have been carried out. Although the use of bulk-rock samples precludesthe identification of precise palaeotemperatures, the trends are valid(Wray and Gale, 2006) and show similar results with oxygen isotopedata based on invertebrates (e.g. Voigt et al., 2004). These agree on agradual increase in thewater temperatures throughout the Cenomanianfollowed by a peak at the Cenomanian/Turonian boundary correspond-ing, according to Jenkyns et al. (1994) and Voigt et al. (2004), to adifference of about 6 °C between the beginning and the end of theCenomanian. Following this peak, temperatures remained high butdecreased gradually during the Turonian before a cooling event in thelate Turonian (Clarke and Jenkyns, 1999). Thus, the absence of represen-tatives of squaliforms, synechodontiforms and to a lesser extenthexanchiforms in Justine-Herbigny is probably related to the warmerclimate that prevailed during the Turonian. This is consistent with thedistribution of modern representatives of the Squalidae, which are ab-sent from intervening tropical or equatorial zones (Compagno et al.,

2005). Similarly, synechodontiforms are mostly recovered in the Borealrealm during the Late Cretaceous.

Despite the absence of the above-cited taxa, the Justine-Herbignyfauna is characterised by a rather high taxonomic distinctness as well asvery high species richness and diversity (low degree of dominance). Therelatively high taxonomic distinctness is typified by the appearanceof numerous batoids (?Platyrhinidae indet., ‘Rhinobatos’ sp.,Micropristis sp.) and other taxa (e.g. Cantioscyllium decipiens, Carchariascf. latus, Pseudocorax duchaussoisi) restricted to the Turonian of Justine-Herbigny and representing diverse higher taxonomic levels. Additionally,many fossils from this fauna represent the first occurrence of elasmo-branch taxa frequently encountered in younger deposits in the Anglo-Paris Basin (including orectolobiforms and many carcharhiniforms). Onthe other hand, many species present in the Cenomanian faunas (mainlypelagic lamniforms) are also reported from Justine-Herbigny, resultingin the clustering of this fauna within the Cenomanian assemblagesin cluster analyses. However, the loss of large lamniforms present inthe Cenomanian (e.g. Anomotodon cf. principalis, Dwardius woodwardi,Palaeoanacorax aff. pawpawensis,Cretoxyrhina denticulata, Paranomotodonangustidens and Squalicorax aff. falcatus) may be related to either thewarmer Turonian climate and/or to the spread of stratified oceanicwatersonto the shelf as a result of the late Cenomanian sea-level rise.

4.1.3. The Coniacian faunaAlthough the Coniacian exposure of Minnis North (Northern

Ireland) is not part of the Anglo-Paris Basin (North of the Proto-Atlantic Basin), this yielded an interesting fauna representing theonly Coniacian elasmobranch assemblage included in this workand the only assemblage sampled from a non-chalky facies (green-sands). Reworking possibly partly occurred on the Minnis Northfauna (some fossils are dark-coloured and abraded whereas othersare pale-coloured and well-preserved) but because there is no differ-ences between the two sub-assemblages in terms of taxic compositionit is unclear whether these correspond to two different assemblages orto differential biostratonomy (Underwood and Ward, 2008). Assuggested by the multivariate analyses and despite its Coniacian age,this fauna shows more similarities with Cenomanian assemblages thanwith Turonian and Santonian–Campanian samples. This is exempli-fied by the large number of taxa present in the Cenomanian andConiacian deposits but absent from the Turonian of Justine-Herbigny(Pararhincodon cf. crochardi, Cederstroemia cf. siverssoni, Paranomotodonangustidens, Squalicorax aff. falcatus, Cretascyliorhinus destombesi,Pseudoscyliorhinus schwarzhansi, Turoniabatis ornatus). Asmentioned ear-lier, the early–middle Turonian probably represents thewarmest climaticepisode for the Late Cretaceous (Clarke and Jenkyns, 1999) and it is veryplausible that the absence of these taxa from the Turonian of Justine-Herbigny is a migratory response to the warm Turonian temperatures.However, no data from the Turonian of the North Atlantic are availableand it is thus difficult to know whether these taxa migrated furthernorth before returning to lower latitudes after the late Turonian coolingevent, or if they found suitable palaeoenvironmental conditions in theTuronian of the north of the Proto-Atlantic Basin. Similarly, it is hard toassess whether these taxa reached the Anglo-Paris Basin in the Coniacian,or remained in cooler waters further north as no data are available. How-ever, Herman (1977) described an early Coniacian fauna from Belgium(Maisières) as well as the fauna from the Glauconie de Lonzée, likely tobe, in part, late Coniacian in age. These faunas yielded remains ofP. angustidens and S. falcatus, alongwith teeth of C. cf. siverssoni (describedas Squatina decipiens) but no remains of the other taxa mentioned above.Thus, the latter taxa were also present in the Anglo-Paris Basin duringthe Coniacian. Therefore, a probable scenario would be that the lateCenomanian–early Turonian global warming constrained the seven spe-ciesmentioned above tomigrate toward coolerwaters of higher latitudes(connection to the Boreal Ocean), and that the subsequent late Turoniancooling phase allowed the development of suitable palaeoenvironmentsfor the species P. angustidens, S. falcatus and C. cf. siverssoni to return


toward lower latitudes. The remaining taxa however,may have remainedwithin the Proto-Atlantic Basin (whichwould have had direct connectionto the Boreal Ocean), after their loss from the Anglo-Paris Basin.

Another similarity betweenMinnisNorth and the Cenomanian faunasis the presence of squaliforms and synechodontiforms. The presence ofhexanchiform remains could have been expected at Minnis Northas taxa belonging to the two other groups (synechodontiforms andsqualiforms) that were thought to prefer cooler waters, are present inMinnis North. A reason for this may come from the nature and the depo-sitional environment of the Coniacian sediments. Glauconitic facies havea broad range of depositional environments: frommoderately anaerobicto strongly oxidising, from cold to warm seawaters and from depths offifteen down to several thousand metres (McRae, 1972). However, thesiliciclastic facies in Northern Ireland rest directly on older (Palaeozoicand Jurassic) rocks and deposited during a widely recognised transgres-sive episode (Hancock and Kauffman, 1979). These are thus documentedas having a near-shore marine origin, probably resulting from theglauconitisation of fragments of volcanic glass or volcanic rocks on thesea (McRae, 1972) during a sedimentary hiatus. This palaeoenvironmentwas probably too shallow for hexanchiforms to be present, a view that isconsistent with the distribution of modern hexanchiforms (observedmainly on continental shelves and slopes). Similarly, this shallowenvironment may also be the limiting factor for the distributionof the small carcharhiniforms (Pteroscyllium hermani, Scyliorhinusbrumarivulensis, Sigmoscyllium. striatum and Pseudoscyliorhinus reussi)and the orectolobiform Pararhincodon. ornatus, which are present inJustine-Herbigny and commonly found in Santonian–early Campaniansediments of the Anglo-Paris Basin. In addition, two out of the threehybodont species (Meristodonoides sp. and Polyacrodus sp.) recoveredfrom theAnglo-Paris Basin are fromMinnis North. It has been suggested(Maisey, 1982; Cappetta et al., 1990; Cavin et al., 2001; Cuny et al.,2005; Vullo, 2007) thatmanyhybodont taxa (excluding ptychodontids)were euryhaline. Hence, the presence of hybodont taxa inMinnis Northis consistent with these observations and with the near-shorepalaeoenvironment suggested for this assemblage. This shallow envi-ronment seems to have been favourable for the lamniform Squalicoraxaff. falcatus and the heterodontiform Heterodontus aff. havreensis,representing 35 and 16% of the dental remains, respectively. Such ahigh proportion of heterodontid remains is unusual in the Late Creta-ceous of the Anglo-Paris Basin. However, some modern species of thegenusHeterodontus are known to prefer shallow sandy (and rocky) sub-strates (Compagno, 2002; Compagno et al., 2005) and thus a similarmode of life is attributed to their Coniacian representatives. Abundantremains of lamellibranchs and brachiopods inMinnis North representedsuitable prey items for these taxa adapted to durophagy (also includingPtychodus). However, H. aff. havreensis is one of the few nectobenthictaxa represented by a large number of teeth inMinnis North (the othersare, to a lesser extent, Chiloscyllium. cf. vulloi and Turoniabatis ornatus).Although the number of nectobenthic species recorded is higherthan the pelagic, the latter dominate in terms of percentage of dentalremains. Indeed, the nectobenthic species (mainly carcharhiniformsand orectolobiforms) are commonly represented by a few teeth only,thus indicating that thesewere transient species preferring other nearbyenvironments. This distribution is probably related to the sandy natureof the sea floor and/or the possibly intermittent dysoxia of the bottomwaters allowing glauconite to develop.

4.2. Santonian–Campanian faunas and phosphatic chalk environments

4.2.1. A relationship between productivity and diversity?According to Jarvis (1980c), a phosphatic chalk is regarded as being a

pelletal chalk containing in excess of 5% phosphorus (P2O5). Chalk suc-cessions containingphosphatic grains of various types occur throughoutthe Late Cretaceous of the Anglo-Paris Basin (Jarvis, 2006) but theSantonian–Campanian phosphatic chalks differ from the latter bytheir thickness, their high phosphate content and their abundance in

southern England and northern France. The long-term deposition ofmarine phosphatic sediments requires a source of phosphorous andother nutrients to promote organic productivity. These phosphatic sed-iments have been extensively studied (Jarvis, 1980a,b,c, 1992, 2006;Jarvis et al., 1994) and the most likely and accepted concept for thebroad deposition of the Santonian–Campanian phosphatic chalks isthat of the development of upwelling systems. These created strongbottom currents able to erode the sea floor and to supply nutrients tothe surface ocean, necessary to promote enhanced marine productivity(Jarvis, 2006). These bottom-currents were likely to be favoured by theopening of the Proto-Atlantic Ocean,whichmodified oceanic circulation(Jarvis, 2006; Esmerode and Surlyk, 2009).

From an ecological point of view, the relationship between produc-tivity and biodiversity/species richness has been the focus of manyworks on modern marine and terrestrial ecosystems. Most studiesagree that productivity affects species richness but underlying causalmechanisms are still poorly known. The most widely hypothesised pat-tern is that of a unimodal relationship (for a review, seeMittelbach et al.,2001), where diversity first increases with productivity at low levelsand then decreases with high productivities, thus producing hump-shaped curves. The other proposed relationship is linear, where diversi-ty increases with increasing productivity. In their review of bothplant and animal studies, Waide et al. (1999) suggested that althoughthe unimodal relationship is common, other patterns (positive and neg-ative linear relationships as well as no relationship) also occur. In thecase of the Santonian–Campanian faunas considered here, there aresubstantial differences in terms of species richness and evenness be-tween assemblages, although all are assumed to represent high produc-tivity environments. Faunas such as Taplow lower horizon, Hallencourt(upper and lower horizon), Stoke Clump, Culver and, to a lesser extentDownend (1 and 2) are represented by low species diversity andevenness. Conversely, faunas from Boxford, Taplow upper horizon,Winterbourne (upper and lower horizons), Séru, Faucouzy (upper andlower horizons),Mont-Août (upper and lower horizons) and, to a lesserextent Villers-devant-le-Thours show high species richness and even-ness. A possible way to assess the level of productivity of thesepalaeoenvironments would be to compare the phosphate contents ofthe different horizons sampled (higher P2O5 contents reflect higher pro-ductivities), but these were not available. However, the correlation be-tween low diversity faunas and the presence of a well-cemented basalhardground underlying the pelletal phosphatic chalk from where theywere sampled is striking. Conversely, high diversity faunas were sam-pled either from pelletal phosphatic chalk above omission surfaces orfrom nodular phosphatic chalk (the ‘basal lag’ sensu Jarvis, 1980c,1992, 2006) immediately above hardgrounds. These observationsallowed amodel to be developed for the Santonian–Campanian elasmo-branch communities in which the heterogeneity of the environment isthe main factor controlling diversity. According to Jarvis (1980c, 1992,2006) the formation of a cuvette (Fig. 9A) is initiated by the action ofstrong bottom currents. These winnowed the sea floor, cutting intopreviously deposited white chalk and preventing sediment deposition.Cementation of the hardground subsequently takes place, along withintensive bioturbation under a waning current regime. The basalhardground is colonised by various and diverse organisms that favourthe deposition of phosphate, which is accumulated in the centre of thecuvette, along with the transported coarse sediment making up thebasal lag. As the sedimentation continues, the basal hardground is pro-gressively less exposed allowing finer calcarenite sediments to developand gradually fill in the cuvette. Hence, the development of a basalhardground provides a peculiar heterogeneous environment (Fig. 9B)within the otherwise homogenous surrounding chalk sea. Variousniches were available including the hardground itself, its less induratemargins, the nearby soft white chalk and the patches of nodularcalcarenite. These co-occurring soft and hard substrates allowed coloni-sation of a wide range of both epi- and infaunal invertebrate communi-ties, commonly recovered in these facies (echinoderms, asteroids,


bivalves, brachiopods, tube-worms, sponges and corals). Similarly,this variety of niches was occupied by diverse elasmobranch taxaof various environmental preferences, with a wide range of invertebratesrepresenting awide range of prey items. A similar environmental contextwas found in the case of omission surfaces with more and less induratedsubstrates co-occurring in a restricted area. Conversely, as the depositionof calcarenitic sediment continued, the vast majority of the substrate wasoccupied by fine calcarenite (Fig. 9C). Hence, the environment becamemore homogenous thus resulting in the dominance of few groupsadapted to soft substrates. The consequence of this habitat homoge-nisation for the elasmobranch communities was i) the disappearance oftaxa preferring hard substrates or feeding on corresponding prey itemsand ii) the competition between taxa adapted to soft substrates. This ledto a decrease in elasmobranch diversity and dominance, whereas therare presence of remains of other taxa is due to their lateral transportfrom the margins of the cuvette into the calcarenite.

Among the taxa commonly present in these lowdiversity faunas, theorectolobiform Chiloscyllium frequens is by far the most dominantspecies (representing up to 75% of the material), the soft substrateprovided by the calcarenite being favourable for this nectobenthicspecies. In addition, other small nectobenthic carcharhiniforms (e.g.Palaeogaleus havreensis, Crassescyliorhinus germanicus, Paratriakis tenuis,Prohaploblepharus. riegrafi) are frequently associated. Conversely, largepelagic lamniforms are very few. Themitsukurinid Anomotodon hermaniis the only lamniform commonly found in numbers, whereas it is repre-sented by a few teeth in high diversity faunas. The anacoracid Squalicoraxkaupi however, is well represented in only two low diversity faunas(Hallencourt upper horizon and Downend 1), resulting in a large numberof dental remains of pelagic individuals in these assemblages. Thesefaunas were sampled from the two largest cuvette structures, being1 km long, 250 m wide and 30 m deep in Hallencourt (Jarvis, 1992)and of larger dimensions in Downend, where large-scale sedimentslump events have been described (Gale, 1980). It has been noted thatrepresentatives of the genus Squalicorax are abundant in the Coniacianshallow waters of Northern Ireland and it is expected that S. kaupi wasabundant in Hallencourt and Downend because these large structuresprovided large-scale topographic highs representing adequateenvironments for this species. The presence of numerous remainsof Squalicorax in these three faunas is therefore attributed to theirshallower palaeoenvironments. In addition, the numerous topographicstructures created by the large-scale slumps and slides in Downendmost likely added some habitat heterogeneity among the homogeneouscalcarenite facies and may explain why faunas from this locality showan intermediate degree of diversity and dominance.

There is a marked correlation between high taxonomic distinctnessand low diversity in the Santonian–early Campanian faunas. Althougha high taxonomic distinctness would have been expected for assem-blages corresponding to heterogeneous palaeoenvironments, the oppo-site relationship seems to prevail. This pattern is due to the fact that,although faunas sampled from heterogeneous palaeoenvironments arevery diverse, they are dominated by taxa representing few higher taxo-nomic ranks (mainly scyliorhinids, hemiscylliids and triakids, corre-sponding to the orders Carcharhiniformes and Orectolobiformes). Onthe other hand, in addition to the presence of Paraorthacodus conicusrepresenting the synechodontiforms (s.l.), low diversity faunas have asmaller number of taxa but these are representatives of the samehigher taxonomic ranks as high diversity assemblages. Therefore, lowdiversity faunas have a similar or even higher representativeness of

Fig. 9. The trough-like channel (cuvette) and its associated palaeoenvironments. A,Morphology ofdeposition and reworking produces patches of intraclastic phosphatic chalkmaking up the basal laphosphatic chalk. B, Heterogeneous palaeoenvironment associated with the basal lag (similar conpatches of intraclastic chalks, less indurate cuvette margins along with the surrounding whitephosphatic chalk reduces the environment heterogeneity, with harder substrates being present oShark drawing are from Compagno et al. (2005); others are form Integration and Application Net

higher taxonomic levels with a weaker species richness, which resultsin higher taxonomic distinctness values for these assemblages. Howev-er, this relationship does not hold for pre-Santonian and late Campanianfaunas,whichhave representatives of higher taxonomic ranks related todifferent palaeoenvironmental settings.

4.2.2. Relationship between productivity and body sizeOne of the main features of the Santonian–Campanian elasmo-

branch assemblages considered here is the dominance of nectobenthicspecies represented by small teeth. These taxa aremainly representativesof the carcharhiniforms, orectolobiforms and, to a lesser extent, smalllamniforms and squatiniforms. Although it is impossible to assessquantitatively the body size of a fossil species based on its dentalremains, comparisons with modern representatives or modern equiva-lents provide some information. The carcharhiniforms, orectolobiformsand squatiniforms present in these faunas are nectobenthic speciestypically represented by teeth of clutching and clutching/cuttingtypes (Cappetta, 2012) not exceeding 4 mm high and commonly inthe 0.5–2 mm range. These dental types were adapted to predationover abundant bivalve, brachiopod, worm, crustacean, cephalopod andsmall fish faunas commonly found in association with the elasmobranchassemblages. Modern equivalent to these taxa reach a size of about1.5 m long (Squatina, Orectolobus) whereas modern representatives ofhemiscyllids, parascyllids, scyliorhinids and triakids generally reach abody length of 50 cm. Dental remains of large lamniform species(Anomotodon hermani, Squalicorax kaupi, Cretolamna appendiculata)arewell represented in lowdiversity faunas only, although representinga small fraction of the species diversity.

Body size is related to metabolic rate, with large species consumingmore energy than small ones, although the former require less energyper gramme of body weight (Peters, 1983). Studies on modern fish as-semblages have used biomass/size spectra (i.e. the contribution of thedifferent size classes to the total biomass), or similar studies on bodysize distribution, to compare the structure of different communities(Merrett and Haedrich, 1997; Munday and Jones, 1998; Ackermanet al., 2004). Macpherson and Gordoa (1996) used this method on de-mersal fish communities from the Benguela upwelling ecosystem(south-eastern Atlantic) and found that the most productive areaswere where the abundance of the smallest size classes was the highest,with the biomass decreasing with increasing body sizes. These areasare characterised by a dominance of mid-trophic-level predators. Con-versely, less productive areas yielded the lowest abundance of thesmall size classes. The predominance of small size species along withthe dominance of remains of small carcharhinids, scyliorhinids, triakidsand orectolobiforms (representing mid-trophic-level species) in theSantonian–Campanian faunas is therefore consistent with the upwell-ing systems thought to prevail in the Anglo-Paris Basin during thistime interval. However, the reasons for such a body size distributionare poorly understood but the fast turnover rate of small individualscombined with their high densities in a rather restricted productivearea are likely to be more adequate to the unstable eutrophic environ-ments such as the upwelling ecosystems (Macpherson and Gordoa,1996).

4.2.3. Beta diversity of early Campanian faunasCampanian faunas were sampled from distant fossil-rich phosphatic

horizons, which can therefore be regarded as isolated islets of produc-tivity among the fossil-poorwhite chalk. In addition,most of the species

a hypothetical cuvette after Jarvis (2006)with ahardgrounddeveloped at its base. Initial chalkg. Declining current velocities and increasing organic-matter fluxes leads to the deposition ofditions are expected with omission surfaces). Various niches provided by the hard substrate,chalk, are accessible for the development of diverse faunas. C, The filling of the cuvette byn the cuvette margins only, thus reducing diversity and enhancing dominance.work, University of Maryland Center for Environmental Science (ian.umces.edu/symbols/).


image of


present in these faunas represent benthic or nectobenthic taxa with alesser potential of migration than pelagic taxa and, unlike most bonyfishes, elasmobranchs have no planktonic stage during their develop-ment, thus reducing their dispersal capabilities compared to bony fishes.Despite this, results show no evidence of provinciality among the earlyCampanian assemblages considered. However, it is probable that thetime scale used (the early Campanian spans approximately 5 Ma), al-though being the shortest available time-binwith sufficient data, may in-fluence the trend observed and some differencesmay be stratigraphicallyrelated. However, the cluster analyses generally show no differentiationbetweenSantonian and early Campanian faunas, thus indicating that elas-mobranch communities were relatively stable through this period. Thissuggests that the low density of elasmobranch remains in the ‘pure’white chalk does not necessarily indicate an unsuitable environment forelasmobranchs, as these were capable of crossing rather large distancesin this environment to reach other islets of high productivity. In addition,most of these species were possibly able to cope with the white chalkpalaeoenvironment. This is suggested by the presence of few scyliorhinid,orectolobiform, squatiniform teeth and lamniform tooth fragments infossil-poor Turonian white chalk samples (D.J. Ward, pers. com.). Thelow number of elasmobranch remains in white chalk may also be relatedto the corresponding faster sedimentation rate (3 cm ka−1) comparedwith that of phosphatic chalk (0.3–1.2 cm ka−1; data from Jarvis, 2006).Another possible reason for this low beta diversity is the abundanceof large channel systems in the early Campanian. In addition tothose sampled in this work, numerous comparable or larger channelshave been reported by seismic studies from the Anglo-Paris Basinbut also from the Danish, German and Dutch North Sea areas (Lykke-Andersen and Surlyk, 2004; Surlyk and Lykke-Andersen, 2007; Surlyket al., 2008; Esmerode and Surlyk, 2009). It is therefore likely thatthe abundance of sea floor palaeotopographies in the Anglo-Parisand North Sea basins provided a large number of suitable habitats in asufficiently restricted area for the species to migrate depending on thelocal ecological conditions (e.g. species preferring hard substrateswould easily find similar conditions in a neighbouring channel whensuch substrates were locally covered with calcarenite). Consequently,the palaeoecological settings can be regarded as homogeneous atbasin scale. Finally, the Late Cretaceous climatic features may haveplayed a role in the resulting low provinciality of the early Campanianelasmobranch faunas. The warm climate was associated with a lowerlatitudinal gradient than today (Amiot et al., 2004; Jenkyns et al.,2004; Pucéat et al., 2007) which, along with a uniform bottom currentsystem reported from the Anglo-Paris Basin [NNW–SSE direction(Jarvis, 1992, 2006)], suggests homogeneous conditions for the Basinin the early Campanian.

4.2.4. Faunal variations in the Santonian–Campanian intervalDespite differences in species richness and diversity, the Santonian–

early Campanian faunas show little variations in terms of taxonomiccomposition, as indicated by their constant grouping in multivariateanalyses. It should be noted that this grouping does not systematicallylink together faunas sampled from successive horizons at a given site.Thismay be attributed to the steady upwelling systems, nutrient supplyand productivity throughout this period, leading to a homogeneous andconstant taxonomic structure of the elasmobranch communities. Thishomogeneity is exemplified by the presence of over fifteen smallnectobenthic species (mostly carcharhiniforms and orectolobiforms,commonly found in the early Santonian–late Campanian faunas oreven in older deposits (Justine-Herbigny, Minnis North). There is, how-ever, a turnover between the Santonian and early Campanian faunaswith sixteen Santonian taxa not represented in the early Campanian.Considering the large sample size for the early Campanian faunas(about 30,000 teeth), it is very unlikely that the sixteen Santonian spe-cies were present in the early Campanian but not recovered. However,the Santonian/Campanian boundary represents an episode of markedand rapid cooling of the ocean surface waters (e.g. see Jenkyns et al.,

1994, 2004; Clarke and Jenkyns, 1999) and it is more probable thatmost of these species favoured the warmer Santonian ocean waters andmigrated (local extinction) or went globally extinct at the Santonian/Campanian boundary (Guinot, 2013). Yet, there are no reports of thesespecies in younger deposits that could suggest any migratory patterns.Among the ten species that appear in the early Campanian, only one(Paraorthacodus conicus) can be considered as common, being presentin 4 early Campanian faunas. Other taxa are represented by very fewteeth only, in a single or less commonly, two early Campanian faunas.P. conicus has been reported from the Campanian of the North Sea Basin(Davis, 1890; Müller, 1989) and Campanian to Maastrichtian deposits ofBelgium (Leriche, 1929; Herman, 1977) and seems restricted to Borealand Intermediate realms (sensu Burnett, 1998).

In spite of the numerous species shared by the Santonian–earlyCampanian assemblages and the two late Campanian faunas fromMont-Août, the latter differs from others in some respects. These differ-ences are typified by the loss of thirty one taxa previously recorded inthe Santonian–early Campanian interval. Yet, it is very probable thatthe small number of late Campanian faunas considered here (sampledfrom a single site), along with their small sample size, resulted into anincomplete view of the late Campanian diversity in the Anglo-ParisBasin. Nevertheless, among the seven species restricted to the lateCampanian, six (Anomotodon genaulti, Scyliorhinus monsaugustus,Squatirhina cf. lonzeensis, Heterodontus sp. 2, Hemiscylliidae indet. 2,Odontaspididae indet. 1) have congeneric or closely-related representa-tives limited to the Santonian–early Campanian assemblages (respec-tively Anomotodon hermani, Scyliorhinus brumarivulensis, Squatirhinalonzeensis, Heterodontus sp. 3/Heterodontus boussioni, Adnetoscylliumangloparisi, Carcharias adneti). This suggests a faunal turnover, whichprobably occurred in response to the global cooling that took place atthe Santonian/Campanian boundary and continued throughout theCampanian. Thepresence of the squalidCentrophoroides cf. appendiculatusin theMont-Août faunas agreeswith a temperature-driven faunal changeand, more generally, with the presence of squalids (Protosqualus andCentrophoroides) as indicative of cooler ocean waters, as suggested byboth their previously discussed distribution and that of some modernrepresentatives of this group.

4.2.5. Interrelationships between elasmobranch communities andenvironmental factors

The observationsmade on palaeoecological features of the Santonian–Campanian elasmobranch communities allowed global interrelation-ships between elasmobranch ecological patterns and environmentalfactors to be defined (Fig. 10). These interrelationships rest on twomajor environmental factors: productivity and environment heteroge-neity. Productivity is amplified by the nutrient runoff of continental or-igin and light and oxygen input. In addition, high biological productionsare the result of the pre-existing abundance of phosphorus (Cayeux,1939; Charles, 1953; Cook, 1976) and can be considered a consequenceof high phosphorus concentrations in sea waters. In reverse, the decayof biological organisms releases phosphorus in sea waters. Upwellingsystems provide nutrients to surface waters, thus enhancing biologicalproductivity. Additionally, these upwellings are associated with strongbottom currents which eroded the Santonian–Campanian sea floor,hence increasing habitat heterogeneity. Conversely, habitat heteroge-neity is reducedwhen bottom currents wane and allow sediment depo-sition. The combination of aerobic conditions, high productivity andhabitat heterogeneity lead to an increase in evenness and species rich-ness. However, high species densities in restricted environmentsimply small body sizes due to limited resources. The high species rich-ness also results in the overrepresentation of a few groups, thusrestricting the taxonomic distinctness of the elasmobranch assem-blages. On the other hand, taxonomic distinctness is enhanced in thecontext of cool climatic settings, with the presence of squaliforms andhexanchiforms representing additional higher taxonomic orders.

Fig. 10. Theoretical interrelationships between elasmobranch communities and environmental factors. Solid lines indicate positive influence of the environmental factors whereas dashedlines indicate negative influence.


4.3. The place of the Anglo-Paris faunas amongst other Late Cretaceousassemblages from NW Europe

4.3.1. Cenomanian–Coniacian faunasThree main clusters were recognised in the dendrograms including

the 50 faunas considered here. Cluster II encompasses most of theCenomanian, Turonian and Coniacian faunas involved in the analysis.The group II-1 represents Cenomanian elasmobranch assemblages ex-clusively sampled from the Aquitaine Basin (SW France), situated be-tween the Armorican and Central Massifs. These faunas thereforecorrespond to a Tethyan-influenced palaeoenvironment which, alongwith their peculiar corresponding depositional environment, led totheir grouping in a well-differentiated cluster. With the exception of thelate Cenomanian fauna from l'Amas, these (early–middle Cenomanian)assemblages correspond to paralic to neritic coastal palaeoenvironmentsprobably representing mangrove-like, or closely-related environments(Vullo et al., 2003, 2007). Although faunas from Lussant (Landemaine,1991) and Les Renardières (Vullo et al., 2007) correspond to the samehorizon of the same locality, they are not closely placed in the cluster.Similarly, other assemblages studied by Landemaine (1991; Chabonne,Moulin de la Chaussée) are separated from the coeval (or sub-contemporaneous) and geographically close faunas described by Vulloet al. (2007). These differences are due to related to distinct samplingand processing methods as the faunal contents in Landemaine (1991)were considered and revised by Vullo et al. (2007). These coastal Tethyanelasmobranch assemblages are characterised by the presence ofhybodonts (Meristodonoides, Polyacrodus and Tribodus), smallorectolobiforms (e.g. Chiloscyllium, Almascyllium, Cantioscyllium) andrajiforms (e.g. diverse sclerorhynchids, Archingeayia, Engolismaia,Hamrabatis) and by the lack of scyliorhinids, synechodontiforms,hexanchiforms and squaliforms. The late Cenomanian fauna from l'Amasrepresents more open marine conditions but still relatively shallow, anddiffers in the absence of hybodontiforms and in the small number oforectolobiforms and batoids. Lamniforms are also well represented in

these assemblages. Among them, taxa such as Scapanorhynchus minimus,Archaeolamna, Pseudoscapanorhynchus compressidens and Cretolamna arealso present in the Anglo-Paris Basin, thus indicating that these taxawerecosmopolitan and tolerated Tethyan and Intermediate to Boreal environ-mental settings. On the other hand, taxa like Cenocarcharias, Roulletia,Squalicorax baharijensis and ‘Carcharias’ amonensis, are restricted to theTethyan realm and Western Interior Seaway.

Faunas present in the other cluster are divided into groups, II-2 andII-3, separating the Cenomanian–Coniacian faunas from Belgium fromthe Anglo-Paris and Münster Basin assemblages (see above for discus-sion on the placement of the middle Turonian fauna of Justine-Herbigny and on the age of the Glauconie de Lonzée). As far as theCenomanian assemblages are concerned, faunas from southern Englandand NW Germany (STM, TTE, BRG and ASC) are separated from thoseof Belgium (TOU and MSR). In their study of the clay mineralogyof Cenomanian–Campanian chalks from the eastern Paris Basin,Deconinck et al. (2005) suggest that the high early Cenomanian detritalclay content indicates erosion of exposed landmasses and evoked theLondon–Brabant Massif as most probable exposed massif at this time.However, if the London–Brabant Massif represented a geographicalbarrier, Cenomanian assemblages from England, Belgium and Germanyshould be distinct. Yet, English and German faunas are very similar,suggesting connections between these regions and similar palaeo-environmental settings. Herman (1977) described the faunas of Tournaiand Montigny-sur-Roch on the basis of surface-collected materialbelonging to museum collections. As a result, the very large majorityof the small number of taxa reported belongs to lamniforms andptychodontids. With the exception of Polyacrodus and Cretodus, alltaxa reported fromBelgium are present in the English faunas. It is there-fore very likely that the differences seen between these faunas are dueto a bias in the representation of smallmaterial from Belgium. However,the rich Cenomanian faunas from NW Germany and southern Englandare very similar, sharing thirty one genera. These are represented by nu-merous lamniforms, some carcharhiniforms (particularly scyliorhinids)

image of Fig.�10


and Protosqualus, Notorynchus, Synechodus and Squatina. With the ex-ception of some lamniforms, these taxa are not represented in theshallow-waters and Tethyan-influenced faunas from the AquitaineBasin and are thus considered indicative of Intermediate to BorealRealms.

The issues related to sample bias affecting faunas described byHerman (1977) render difficult comparisons between Turonian andConiacian faunas. However, assemblages from the Coniacian of North-ern Ireland and the Glauconie de Lonzée and, to a lesser extent fromMaisières, show similarities that support some of the interpretationsmade earlier. Similar toMinnis North, faunas fromLonzée andMaisièreswere sampled from glauconitic transgressive facies representing shal-low environments (Leriche, 1929). Similarly to the Minnis Northfauna, carcharhiniforms, orectolobiforms and hexanchiforms are notor poorly represented whereas hybodont, anacoracid, heterodontidand ptychodontid remains are common, thus confirming the favourableconditions provided by the shallow glauconitic environments to the lat-ter taxa.

Cenomanian assemblages fromSpeeton (north-east England) arewellseparated from other coeval faunas and groupedwithin cluster I. The suc-cession at Speeton deposited in the Cleveland Basin, north to the MarketWeighton Structure (Mitchell, 1996). This succession corresponds torelatively deep water deposits (Mitchell and Langner, 1996). Some taxareported from southern England such as Protosqualus, Notorynchus,Synechodus, Squatina as well as some carcharhiniforms (Cretascyliorhinus,Pteroscyllium, Scyliorhinus) are present in the Speeton faunas, but thesediffer in other respects. Among those, the absence of diverse lamniforms,the presence of Hexanchus along with that of other squaliforms (Squalusand an undetermined etmopterid) is characteristic. These features areattributed to both the deep water environment and the fully Boreal set-tings,which appear suitable for these taxa. The early–middle Cenomanianfauna from Ascheloh (NWGermany) shares muchmore similarities withthe southern England faunas than with the Speeton assemblages thus in-dicating that although the latter and NWGermanywere part of the samebasin (North Sea Basin), environmental conditions in the southern part ofthe North Sea Basin (Münster Basin) were more comparable to those inthe Anglo-Paris Basin.

4.3.2. The Santonian–Campanian faunasSantonian–Campanian elasmobranch assemblages from NW Europe

are arranged into three sub-clusters among cluster III. Cluster III-3encompasses Santonian–Campanian faunas from the Anglo-Paris Basinand those described by Herman (1977) from the late early (Trivières)and late (Obourg) Campanian of the Mons Basin (Belgium). It is note-worthy that the grouping of the Anglo-Paris faunas is different fromthat seen in previous analyses, which is due to the large number offaunas included in this study, thus removing precision from the results.Although the fauna from the Craie d'Obourg is very similar to coevalassemblages from Mont-Août (see earlier), the Trivières fauna differsfrom contemporaneous (late early Campanian) assemblages from theAnglo-Paris Basin (Downend 1 and 2). The Belgian fauna yieldedrepresentatives of the squaloid Centrophoroides, a genus absent fromthe Anglo-Paris Basin prior to late Campanian. However, the only lateearly Campanian faunas studied from the Anglo-Paris Basin were sam-pled from coeval horizon in the same locality (Downend) situatednear the western margin of the Basin. Considering the hypothesis of aproto-Gulf Stream penetrating the Anglo-Franco-Belgian Basin fromthe west (Luyendyk et al., 1972; Hart, 1976; Jarvis, 1980c; Hay, 2008;Esmerode and Surlyk, 2009), it is probable that Centrophoroides pre-ferred cooler waters present of the Mons Basin (close to the North SeaBasin).

Cluster III-2 groups together the late Campanian faunas from theAquitaine Basin. Although some taxa that can be considered ubiquitousin the late Campanian of NW Europe (e.g. Squatina (Cretascyllium)hassei, Scyliorhinus elongatus, Pseudocorax laevis, Carcharias adneti,Heterodontus, Palaeogaleus, Crassescyliorhinus are present in western

France), the Aquitaine Basin faunas show specificities. Numeroustaxa (mainly lamniforms) such as Paranomotodon, Protolamna,Serratolamna, Plicatoscyllium and Rhombodus are restricted to thispalaeogeographical area. These also lack squalids, triakids and smallorectolobiforms such as Pararhincodon, Chiloscyllium and other smallhemiscylliids, which are common in more northern regions (see Vullo,2005). These features can be regarded as the signature of Tethyan-influenced faunas as the genera Rhombodus, Plicatoscyllium andSerratolamna have been reported from the Late Cretaceous of N. Africa(Arambourg, 1952), southern Western Interior Seaway (Case andCappetta, 1997; Becker et al., 2006) and Spain (Cappetta and Corral,1999). However, the presence of many late Campanian wide-rangingtaxa in the Aquitaine Basin indicates that the closure of the Basse-LoireStrait (see Vullo, 2005) did not preclude faunal exchanges with moreBoreal areas and that observed faunal differences are more likely relatedto climatic contrasts between basins.

Early and late Campanian elasmobranch assemblages from NWGermany (Münster Basin) are groupedwithin cluster III-1. These faunasshow many similar characteristics with those from the Anglo-ParisBasin. Among them, the dominance of small nectobenthic taxa isnoteworthy. In addition, small triakids (Paratriakis, Palaeotriakis,Palaeogaleus) and scyliorhinids (Crassescyliorhinus, Scyliorhinus), alongwith orectolobiforms (Pararhincodon, Chiloscyllium), squatiniforms,Synechodus, Heterodontus and small Scapanorhynchus are representedin both Basins, although not dominating the faunas from the MünsterBasin (see Hübner and Müller, 2010). However, the specificity of thesefaunas is due to their high diversity, and dominance, of squaliforms(see Müller, 1989; Müller and Schöllmann, 1989; Hübner and Müller,2010). Besides the squalid Centrophoroides cf. appendiculatus alsopresent in the Anglo-Paris Basin, representatives of the genus Squalus(Squalus vondermarcki) were also reported from these deposits.Additionally, etmopterids (Eoetmopterus), somniosids (Centroscymnus,Cretascymnus), centrophorids (Deania-like indeterminate taxon) andpossibly echinorhinids are alsowell represented. Such squaliformdiver-sity is unknown from other pre-Maastrichtian faunas. Although thepresence of the squalids Protosqualus and Centrophoroides seems to bemore related to temperature than depth, such a relationship is lessstraightforward for the other squaliform groups. Indeed, modern repre-sentatives of these groups have a wide range of habitats and geograph-ical areas and most of them are found in outer shelves and continentalslopes down to more than a thousand metre deep, with shallower re-cords generally corresponding to cool waters, although some ofthese deep water species tend to migrate towards shallower waters atnight for feeding (e.g. Euprotomicrus; see Compagno 1984). In addition,Squalus and undetermined etmopterid remains are known fromCenomanian deposits of Speeton and although these correspondto the Boreal Realm, the sediments also indicate a rather deeppalaeoenvironment. Despite this, numerous taxa shared between thelate Campanian faunas from Belgium and NE France, along with thepresence of most of these taxa in the early–late Campanian of theMünster Basin indicate that the presence of diverse squaliforms is notdriven by cooler climates but more likely by depth. This is supportedby Schönfeld et al. (2000) and Voigt et al. (2008) who indicated that aperiod of maximal flooding was reached in the mid Campanian in theMünster area and that the corresponding distal facies represented bypelagic chalk was indicative of water depths of 150–200 m or evenmore (see Thies and Müller, 1993). A deep-water environment is con-sistent with the small number non-squaliform taxa, which are likelyto have been transported from shallower waters by turbiditic events(Hübner and Müller, 2010).

5. Conclusion

In this paper, various detailed palaeoecological features of LateCretaceous elasmobranch communities in the Anglo-Paris Basin areidentified and placed into a broader palaeoecological context among


the faunas from NW Europe. The use of univariate and multivariateanalyses based on the taxonomic characteristics of these faunas, alongwith diversitymeasurements and qualitative observations, allowed var-ious patterns to be pointed out. Taxonomic ordinationmethods indicat-ed twomain groups of faunas in the Anglo-Paris Basin: the Cenomanianand Coniacian faunas and the Santonian–Campanian faunas, theTuronian assemblages of Justine-Herbigny showing intermediate char-acteristics. This, along with other ecological indices allowed numerousfeatures to be proposed:

– Cenomanian faunas are characterised by a large number oflamniforms and by the presence of the squalid Protosqualus andthe hexanchid Notorynchus. As in modern ecosystems, the relativelyshallow and mixed waters near a shelf break front are likely to haveprovided suitable environment for the presence of a diverse commu-nity of apex predators.

– The small number of nectobenthic species and the dominance of re-mains belonging to pelagic taxa in the middle Cenomanian faunasindicate a hostile sea floor context in southern England, probably re-lated to dysoxic conditions.

– The absence of hexanchids, synechodontiforms and squalids in themiddle Turonian correlateswith amaximum in palaeotemperatures.Additionally, the presence of diverse carcharhiniform andorectolobiform taxa commonly present in Santonian–Campanianfaunas and the smaller number of large lamniforms indicate achange in environmental conditions probably related to the dramat-ic late Cenomanian sea level rise, which resulted in the spread ofoceanic waters onto the shelf.

– The abundance of remains of Squalicorax and Heterodontus in theConiacian shallow glauconitic facies of Northern Ireland indicates asuitable palaeoenvironment for these taxa. In addition, the presenceof Cenomanian taxa in the Coniacian fauna suggests a probable lateCenomanian/early Turonian migration towards cooler northern At-lantic waters in response to the warming climate, with the subse-quent late Turonian global cooling allowing the development offavourable palaeoenvironmental conditions for some of these taxato return to lower latitudes.

– A model is proposed to explain the ecological features of theSantonian–Campanian faunas in which the heterogeneity of thehabitat is the main factor controlling elasmobranch diversity andevenness. Accordingly, high diversity faunas showing low degreesof dominance correspond to heterogeneous environments whilelow diversity assemblages are related to homogeneous environmentsleading to the dominance of few species (particularly Chiloscylliumfrequens).

– The dominance of species of small size in Santonian–Campanianfaunas is similar to the patterns observed in modern upwelling envi-ronments. The high species density in these unstable eutrophic envi-ronments limits resources and favours small species with highturnover rates.

– The low beta diversity of the early Campanian faunas suggests thatalthough these assemblages were distributed as isolated islets ofproductivity represented by upwelling erosional channels, the largenumber of such palaeoenvironments in the Anglo-Paris Basin andelsewhere in northern Europe provided a wide range of habitats in asufficiently restricted area for species to migrate depending on thelocal ecological conditions.

– Similarities in taxonomic composition of the Santonian–Campanianfaunas indicate a steady basin-scale palaeoenvironment provided bythe continuous upwelling systems supplying high productivities.However, a faunal turnover is identified between the Santonian andearly Campanian faunas. This is probably related to the correspondingrapid global cooling represented, among others, by the presence ofParaorthacodus conicus, which shows Boreal affinities. The continuouscooling induced faunal replacements in the late Campanian as well asthe presence of the squalid Centrophoroides.

Numerous recently published Late Cretaceous faunas from NWEurope were also considered. Although sampling biases occur in somefaunas, the use of hierarchical clustering allowed large-scale ecologicalgroupings to be identified:

– Three main provinces stand out in the Cenomanian of NW Europe.The Aquitaine Basin is represented by Tethyan shallow water taxawhereas faunas from NE England are characterised by Boreal taxa.Anglo-Paris and NW Germany faunas are very similar, thus indicat-ing that although the NE England and NW Germany faunas belongto the same basin (North Sea Basin), the environmental conditionsin the southern part of the latter were more similar to those in theAnglo-Paris Basin.

– Numerous ubiquitous taxa are present in the Campanian of theAquitaine, Münster and Mons Basins. However, the former is typi-fied by thepresence of taxa reported from theTethyanRealm. Strongsimilarities between late Campanian faunas from northern France,Belgium and NWGermany were identified. However, NWGermanyfaunas differ in the presence and abundance of diverse squaliformsrelated to deeper marine palaeoenvironments of the Münster Basin.

Supplementary data to this article can be found online at http://dx.doi.org/10.1016/j.palaeo.2013.07.027.

Acknowledgements

C.J. Underwood, H. Cappetta, S. Adnet, D.J. Ward, A.S. Gale and I.Jarvis are thanked for their advice, constructive comments, and discus-sions. M.J. Vavrek provided extremely valuable help with beta diversitymethods and R codes. P. Upchurch, C.J. Underwood, M. Richter, S. Adnetand A. Müller commented on early drafts of this work. Constructivecomments made by R. Vullo and an anonymous reviewer greatly im-proved the quality of this paper. This study was largely funded by theFrench Centre National de la Recherche Scientifique and the Universityof London Central Research Fund.

References

Ackerman, J.L., Bellwood, D.R., Brown, J.H., 2004. The contribution of small individuals todensity–body size relationships: examination of energetic equivalence in reef fishes.Oecologia 139, 568–571.

Adnet, S., 2000. Les élasmobranches fossiles du Paléogène des Landes (Sud Ouest, France).(Ph.D. Thesis) Implications dans la connaissance des communautés d'élasmobranchesd'eaux profondes. Evolution des Squaliformes et paléoécologie. Université MontpellierII (211 pp.).

Agassiz, L., 1843 (1833–1844). Recherches sur les poissons fossiles. 3, p. 422.Amiot, R., Lécuyer, C., Buffetaut, E., Fluteau, F., Legendre, S., Martineau, F., 2004. Latitudinal

temperature gradient during the Cretaceous Upper Campanian–Middle Maastrichtian:δ18O record of continental vertebrates. Earth and Planetary Science Letters 226,255–272.

Arambourg, C., 1952. Les vertébrés fossiles des gisements de phosphates (Maroc-Algérie-Tunisie). Notes et Mémoires du Service géologique du Maroc 92, 1–372.

Becker, M.A., Chamberlain Jr., A., Wolf, G.E., 2006. Chondrichthyans from the ArkadelphiaFormation (Upper Cretaceous: UpperMaastrichtian) of Hot Spring Country, Arkansas.Journal of Palaeontology 80, 700–716.

Burnett, J.A., 1998. Upper Cretaceous. In: Bown, P.R. (Ed.), Calcareous Nannofossil Biostra-tigraphy. Chapman and Hall, London, pp. 132–199.

Cappetta, H., 1980a. Les sélaciens du Crétacé supérieur du Liban. I. Requins.Palaeontographica Abteilung A 168, 69–148.

Cappetta, H., 1980b. Les sélaciens du Crétacé supérieur du Liban. II. Batoides.Palaeontographica Abteilung A 168, 149–229.

Cappetta, H., 2012. Chondrichthyes (Mesozoic and Cenozoic Elasmobranchii: Teeth).VerlagF, Pfeil, Munich.

Cappetta, H., Corral, J.C., 1999. Upper Maastrichtian selachians from the Condado deTrevino (Basque–Cantabrian Region, Iberian Peninsula). Estudios del Museo deCiencias Naturales de Alava 14, 339–372.

Cappetta, H., Buffetaut, E., Suteethorn, V., 1990. A new hybodont shark from the LowerCretaceous of Thailand. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen11, 659–666.

Case, G.R., Cappetta, H., 1997. A new selachian fauna from the late Maastrichtian of Texas(Upper Cretaceous/Navarroan; Kemp Formation). Münchner GeowissenschaftlicheAbhandlungen 34, 131–189.

Cavin, L., Boudad, L., Kabiri, L., Le Loeuff, J., Rouget, I., Tong, H., 2001. L'évolutionpaléoenvironnementale des faunes depoissonsduCrétacé supérieurdubassindeTafilaltet des régions avoisinantes (Sud-Est du Maroc): implications paléobiogéographiques.Comptes Rendus de l'Académie des Sciences, Paris, série IIa 333, 677–683.



http://refhub.elsevier.com/S0031-0182(13)00360-X/rf0005







































Cayeux, L., 1939. Les Phosphates de chaux sédimentaires de France.III: ImprimerieNationale, Paris (458 pp.).

Chao, A., Chazdon, R.L., Colwell, R.K., Shen, T., 2005. A new statistical approach forassessing similarity of species compositionwith incidence andabundance data. EcologyLetters 8, 148–159.

Charles, G., 1953. Sur l'origine des gisements des phosphates de chaux sédimentaires. 19eCongrès International de Géologie. Compte Rendu, 11, pp. 163–184.

Clarke, L.J., Jenkyns, H.C., 1999. New oxygen isotope evidence for long-term Cretaceousclimatic change in the Southern Hemisphere. Geology 27, 699–702.

Compagno, L.J.V., 2002. FAO species catalogue. Sharks of the world. An Annotated andIllustrated Catalogue of Shark Species Known to Date. Bulhead, Mackerel and CarpetSharks (Heterodontiformes, Lamniformes, Orectolobiformes), vol. 2. FAO, Roma.

Compagno, L.J.V., Dando, M., Fowler, S., 2005. A Field Guide to the Sharks of theWorld.Harper Collins Publishing Ltd., London.

Compagno, L.J.V., 1984. FAO species catalogue, Vol. 4. An anotated and illustrated cata-logue of shark species known to date. Part 1. Hexanchiformes to Lamniformes, FAO,Roma 249p.

Condit, R., Pitman, N., Leigh, E.G., Chave, J., Terborgh, J., Foster, R.B., Núñez, P., Aguilar, S.,Valencia, R., Villa, G., Muller-Landau, H.C., Losos, E., Hubbell, S.P., 2002. Beta-diversityin tropical forest trees. Science 295, 666–669.

Cook, P.J., 1976. Sedimentary phosphate deposits. In: Wolf, K.H. (Ed.), Handbook ofStrata-bound and Stratiform Ore Deposits. Elsevier, Amsterdam, London, New York,pp. 505–535.

Cuny, G., Suteethorn, V., Kamha, S., 2005. A reviewof the hybodont sharks from theMesozoicof Thailand. In:WANNAKAO, L., YOUNGME,W., SRISUK, K., LERTSIRIVORAKUL, R. (Eds.),International Conference on Geology, Geotechnology and Mineral Resources ofIndochina (GEOINDO 2005) 28–30 November 2005 (Khon Kaen, Thailand).

Dalinkevičius, J.A., 1935. On the fossil fishes of the Lituanian chalk. I. Selachii. Mémoires dela Faculté des Sciences de l' Université de Vytautas le Grand 9, 247–305.

Davis, J.W., 1890. On the fossil fish of the Cretaceous formations of Scandinavia. ScientificTransactions of the Royal Dublin Society 2, 363–4344.

Deconinck, J.-F., Amédro, F., Baudin, F., Godet, A., Pellenard, P., Robaszynski, F., Zimmerlin,I., 2005. Late Cretaceous palaeoenvironments expressed by the clay mineralogy ofCenomanian–Campanian chalks from the east of the Paris Basin. Cretaceous Research26, 171–179.

Dineley, D., Metcalf, S., 1999. Fossil Fishes of Great Britain.Joint Nature Conservation Com-mittee, Peterborough.

Esmerode, E.V., Surlyk, F., 2009. Origin of channel systems in the Upper Cretaceous ChalkGroup of the Paris Basin. Marine and Petroleum Geology 26, 1338–1349.

Gale, A.S., 1980. Penecontemporareous folding, sedimentation and erosion in CampanianChalk near Portsmouth, England. Sedimentology 27, 137–151.

Gale, A.S., Smith, A.B., Monks, N.E.A., Young, J.A., Howard, A., Wray, D.S., Huggett, J.M., 2000.Marine biodiversity through the Late Cenomanian–Early Turonian: palaeoceanographiccontrols and sequence stratigraphic biaises. Journal of the Geological Society of London157, 745–757.

Guinot, G., 2013. Regional to global patterns in Late Cretaceous selachian (Chondrichthyes,Euselachii) diversity. Journal of Vertebrate Paleontology 33, 521–531.

Guinot, G., Cappetta, H., Underwood, C.J., Ward, D.J., 2012a. Batoids (Elasmobranchii:Batomorphii) from the British and French Late Cretaceous. Journal of SystematicPalaeontology 10, 445–474.

Guinot, G., Underwood, C.J., Cappetta, H., Ward, D.J., 2012b. Squatiniformes(Chondrichthyes, Neoselachii) from the Late Cretaceous of southern England andnorthern France with redescription of the holotype of Squatina cranei Woodward,1888. Palaeontology 55, 529–551.

Guinot, G., Underwood, C.J., Cappetta, H., Ward, D.J., 2013. Sharks (Elasmobranchii:Euselachii) from the Late Cretaceous of France and the UK. Journal of SystematicPalaeontology 11, 589–671. http://dx.doi.org/10.1080/14772019.2013.767286.

Hammer, Ø., Harper, D.A.T., 2006. Paleontological Data Analysis.Blackwell Publishing, Oxford.Hancock, J.M., Kauffman, E.G., 1979. The great transgressions of the Late Cretaceous. Jour-

nal of the Geological Society of London 136, 175–186.Harrison, S., Ross, S.J., Lawton, J.H., 1992. Beta diversity on geographic gradients in Britain.

Journal of Animal Ecology 61, 151–158.Hart, M.B., 1976. The mid-Cretaceous successions of Orphan Knoll (North-west Atlantic):

micropalaeontology and palaeo-oceanographic implications. Canadian Journal ofEarth Sciences 13, 1411–1421.

Hay, W.W., 2008. Evolving ideas about the Cretaceous climate and ocean circulation. Cre-taceous Research 29, 725–753.

Herman, J., 1977. Les sélaciens des terrains néocrétacés et paléocènes de Belgique et descontrées limitrophes. Eléments d'une biostratigraphie intercontinentale. Mémoirespour servir à l'Explication des Cartes Géologiques et Minières 15, 1–450.

Hübner, T., Müller, A., 2010. Selachian teeth from the Campanian sediments (Upper Cre-taceous) of the Münsterland Cretaceous Basin (NW-Germany). PaläontologischeZeitschrift 84, 437–455.

Jarvis, I., 1980a. Geochemistry of phosphatic chalks and hardgrounds from the Santonianto early Campanian (Cretaceous) of northern France. Journal of the Geological Societyof London 137, 705–721.

Jarvis, I., 1980b. Palaeobiology of Upper Cretaceous Belemnites from the phosphatic chalkof the Anglo-Paris Basin. Palaeontology 23, 889–914.

Jarvis, I., 1980c. The initiation of phosphatic chalk sedimentation — the Senonian(Cretaceous) of the Anglo-Paris basin. In: Bentor, Y.K. (Ed.), Marine Phosphorites—Geochemistry, Occurrence, Genesis. Special Publication of the Economic Palaeontologistsand Mineralogists, 29, pp. 176–192.

Jarvis, I., 1992. Sedimentology, geochemistry and origin of phasphatic chalks: the UpperCretaceous deposits of Europe. Sedimentology 93, 55–97.

Jarvis, I., 2006. The Santonian–Campanian phosphatic chalks of England and France. Pro-ceedings of the Geologists' Association 117, 219–237.

Jarvis, I., Burnett, W.C., Nathan, Y., Almbaydin, F.S.M., Attia, A.K.M., Castro, L.N., Flicoteaux,R., Hilmy, M.E., Husain, V., Qutawnah, A.A., Serjani, A., Zanin, Y.N., 1994. Phosphoritegeochemistry: state-of-the-art and environmental concerns. Eclogae GeologicaeHelvetiae 87 (3), 643–700.

Jenkyns, H.C., Gale, A.S., Corfield, R.M., 1994. Carbon- and oxygen-isotope stratigraphy ofthe English Chalk and Italian Scaglia and its palaeoclimatic significance. GeologicalMagazine 131, 1–34.

Jenkyns, H.C., Forster, A., Schouten, S., Sinninghe Damste, J.S., 2004. High temperatures inthe Late Cretaceous Arctic Ocean. Nature 432, 888–892.

Landemaine, O., 1991. Sélaciens nouveaux du Crétacé supérieur du sud-ouest de laFrance. Quelques apports à la systématique des élasmobranches. 1. Société Amicaledes Géologues Amateurs 1–45.

Leriche, M., 1929. Les poissons de du Crétacé marin de la Belgique et du Limbourghollandais (note preliminaire). Les résultats stratigraphiques de leur étude. Bulletinde la Société belge de Géologie, Paléontologie et Hydrogéologie 377, 199–299.

Luyendyk, B.P., Forsyth, D., Phillips, J.D., 1972. Experimental approach to thepalaeocirculationof the oceanic surface waters. Geological Society of America Bulletin 83, 2649–2664.

Lykke-Andersen, H., Surlyk, F., 2004. The Cretaceous–Palaeogene boundary at StevnsKlint, Denmarks: inversion tectonics or sea-floor topography? Journal of the Geolog-ical Society of London 161, 343–352.

Macpherson, E., Gordoa, A., 1996. Biomass spectra in benthic fish assemblages in theBenguela System. Marine Ecology Progress Series 138, 27–32.

Maisey, J.G., 1982. The anatomy and interrelationships of Mesozoic hybodont sharks.American Museum Novitates 2724, 1–48.

Mantell, G., 1822. Fossils of the SouthDownsor Illustrations of theGeologyof Sussex.LuptonRelfe, London.

McRae, S.G., 1972. Glauconite. Earth-Science Reviews 8, 397–440.Merrett, N.R., Haedrich, R.L., 1997. Deep-sea Demersal Fishes and Fisheries.Chapman and

Hall, London.Mitchell, S.F., 1996. Foraminiferal assemblages from the late Lower and Middle

Cenomanian of Speeton (North Yorkshire, UK): relationships with sea-level fluctua-tions and watermass distribution. Journal of Micropalaeontology 15, 37–54.

Mitchell, S.F., Langner, D., 1996. Palaeobiology of isocrinid crinoids from the Red Chalk ofnorth-east England. In: Emson, R., Smith, A., Campbell, A. (Eds.), Proceedings of theFourth Echinoderms Colloquium, London/United Kingdom/10–13 April 1995. Echino-derm Research, Balkema, London, pp. 197–207.

Mittelbach, G.G., Steiner, C.F., Scheiner, S.M., Gross, K.L., Reynolds, H.L., Waide, R.B., Willig,M.R., Dodson, S.I., Gough, L., 2001. What is the observed relationship between speciesrichness and productivity? Ecology 82, 2381–2396.

Müller, A., 1989. Selachier (Pisces: Neoselachii) aus dem höheren Campanium(Oberkreide) Westfalens (Nordrhein-Westfalen, NW-Deutschland). Geologie undPaläontologie in Westfalen 14, 1–161.

Müller, A., Diedrich, C., 1991. Selachier (Pisces, Chondrichthyes) aus dem Cenomaniumvon Ascheloh am Teutoburger Wald (Nordrhein-Westfalen, NW-Deutschland).Geologie und Paläontologie in Westfalen 20, 3–105.

Müller, A., Schöllmann, L., 1989. Neue Selachier (Neoselachii, Squalomorphii) aus demCampanium Westfalens (NW-Deutschland). Neues Jahrbuch für Geologie undPaläontologie, Abhandlungen 178, 1–35.

Munday, P.L., Jones, G.P., 1998. The ecological implication of small body fishesamong coral reef fishes. Oceanography and Marine Biology, Annual Review 36,373–411.

Novotny, V., Miller, S.E., Hulcr, J., Drew, R.A.I., Basset, Y., Janda, M., Setliff, G.P., Darrow, K.,Stewart, A.J.A., Auga, J., Isua, B., Molem, K., Manumbor,M., Tamtiai, E., et al., 2007. Lowbeta diversity of herbivorous insects in tropical forests. Nature 448, 692–695.

Oksanen, J., Blanchet, G.F., Kindt, R., Legendre, P., O'Hara, R.B., Simpson, G.L., Solymos, P.,Stevens, M.H.H., Wagner, H., 2010. Vegan: community ecology package (R packageversion 1.17-2). Available at http://vegan.r-forge.r-project.org/.

Peters, R.H., 1983. The Ecological Implication of Body Size.Cambridge University Press.Priem, F., 1908. Etude des poissons fossiles du Bassin Parisien. Annales de Paléontologie

1–144.Pucéat, E., Lécuyer, C., Donnadieu, Y., Naveau, P., Cappetta, H., Ramstein, G., Huber, B.T.,

Kriwet, J., 2007. Fish tooth δ18O revising Late Cretaceous meridional upper oceanwater temperature gradients. Geology 35, 107–110.

R Development Core Team, 2010. R: a language and environment for statistical comput-ing. R Foundation for Statistical Computing. Vienna, Austria.

Sanders, H.L., 1968.Marine benthic diversity: a comparative study. Biometrics 25, 517–535.Sauvage, H.E., 1870. Recherches sur les poissons fossiles des terrains crétacés de la Sarthe.

Annales de la Sociéte Géologique du Nord 2, 1–44.Schönfeld, J., Schultz, M.-G., Spaeth, C., 2000. 4.1 Schleswig-Holstein und nordliches

Niedersachsen. In: Kommission Deutschlands, Stratigraphische (Ed.), Stratigraphieveon Deutschanld III. Die Kreide der Bundesrepublik Deutschland. CourierForschungsinstitut Senckenberg, vol. 226, pp. 65–69.

Surlyk, F., Lykke-Andersen, H., 2007. Contourite drifts, moats and channels in the UpperCretaceous chalk of the Danish Basin. Sedimentology 54, 405–422.

Surlyk, F., Jensen, S.K., Engkilde, M., 2008. Deep channels in the Cenomanian–DanianChalk Group of the German North Sea sector: evidence of strong constructional anderosional bottom currents and effect on reservoir quality distribution. AAPG Bulletin92, 1565–1586.

Thies, D., Müller, A., 1993. A neoselachian fauna (Vertebra, Pisces) from the Late Creta-ceous (Campanian) of Höver, near Hannover (NW Germany). PaläontologischeZeitschrift 67, 89–107.

Underwood, C.J., 2004. Environmental controls on thedistributionof neoselachian sharks andrayswithin the British Bathonian (Middle Jurassic). Palaeogeography, Palaeoclimatology,Palaeoecology 203, 107–126.

Underwood, C.J., Mitchell, S.F., 1999. Albian and Cenomanian (Cretaceous) selachianassemblages from north east England. Special Papers in Palaeontology. 60 9–59.




















































http://dx.doi.org/10.1080/14772019.2013.767286

















































































http://vegan.r-forge.r-project.org/































Underwood, C.J., Ward, D.J., 2008. Sharks of the order Carcharhiniformes from theBritish Coniacian, Santonian and Campanian (Upper Cretaceous). Palaeontology 51,509–536.

Vavrek, M.J., 2012. Fossil: palaeoecological and palaeogeographical analysis tools (R packageversion 0.3.7). Available at http://cran.rproject.org/web/packages/fossil/index.html.

Vavrek, M.J., Larsson, H.C.E., 2010. Low beta diversity of Maastrichtian dinosaurs of NorthAmerica. Proceedings of the National Academy of Sciences 107, 8265–8268.

Voigt, S., Wiese, F., 2000. Evidence for Late Cretaceous (Late Turonian) climate coolingfrom oxygen-isotope variations and palaeobiogeographic changes in Western andCentral Europe. Journal of the Geological Society 157, 737–743.

Voigt, S., Gale, A.S., Flögel, S., 2004.Midlatitude shelf seas in theCenomanian–Turoniangreen-house world: temperature evolution and North Atlantic circulation. Paleoceanography19 PA4020.

Voigt, S., Wagreich, M., Surlyk, F., Walaszczyk, I., Ulincy, D., Cech, S., Voigt, T., Wiese, F.,Wilmsen, M., Niebuhr, B., Reich, M., Funk, H., Michalik, J., Jagt, J.W.M., et al., 2008.Cretaceous. In: McCann, T. (Ed.), The Geology of Central Europe. Mesozoic and Ceno-zoic, Vol. 2. The Geological Society, London, pp. 923–997.

Vullo, R., 2005. Selachians from the type Campanian area (Late Cretaceous), Charentes,western France. Cretaceous Research 26, 1–24.

Vullo, R., 2007. Les vertébrés du Crétacé supérieur des Charentes (Sud-Ouest de laFrance): biodiversité, taphonomie, paléoécologie et paléobiogeographie. (Ph.D.Thesis) Université Rennes 1. Mémoires de Géosciences Rennes, 125, pp. 1–302.

Vullo, R., Neraudeau, D., Videt, B., 2003. Un faciès de type falun dans le Cénomanien basalde Charente-Maritime (France). Annales de Paléontologie 89, 171–189.

Vullo, R., Cappetta, H., Neraudeau, D., 2007. New sharks and rays from the Cenomanianand Turonian of Charentes, France. Acta Palaeontologica Polonica 52, 99–116.

Waide, R.B., Willig, M.R., Steiner, C.F., Mittelbach, G., Gough, L., Dodson, S.I., Juday, G.P.,Parmenter, R., 1999. The relationship between productivity and species richness.Annual Review of Ecology and Systematics 30, 57–300.

Warwick, R.M., Clarke, K.R., 1995. New “biodiversity” measures reveal a decrease in taxo-nomic distinctness with increasing stress. Marine Ecology Progress Series 129, 301–305.

Warwick, R.M., Clarke, K.R., 1998. Taxonomic distinctness and environmental assessment.Journal of Applied Ecology 35, 532–543.

Whittaker, R.H., 1960. Vegetation of the Siskiyou Mountains, Oregon and California.Ecological Monographs 30, 279–338.

Whittaker, R.H., 1972. Evolution and measurement of species diversity. Taxon 21, 213–251.Woodward, A.S., 1911. The fishes of the English Chalk. VI. Monographs of the

Palaeontological Society of London, 64 185–224.Woodward, A.S., 1912. The fishes of the English Chalk. VII. Monographs of the

Palaeontological Society of London, 65 225–264.Worm, B., Lotze, H.K., Myers, R.A., 2003. Predator diversity hotspots in the blue ocean.

Proceedings of the National Academy of Sciences 100, 9884–9888.Wray, D.S., Gale, A.S., 2006. The palaoenvironment and stratigraphy of Late Cretaceous

Chalks. Proceedings of the Geologists' Association 117, 145–162.




http://cran.rproject.org/web/packages/fossil/index.html





































Documents

Late Cretaceous elasmobranch palaeoecology in NW Europe