Fossil mesostigmatid mites (Mesostigmata: Gamasina,Microgyniina, Uropodina), associated with longhorn beetles(Coleoptera: Cerambycidae) in Baltic amber
Jason A. Dunlop & Jen Kontschn & Michael Zwanzig
Received: 14 January 2013 /Revised: 25 February 2013 /Accepted: 1 March 2013 /Published online: 2 April 2013# Springer-Verlag Berlin Heidelberg 2013
Abstract Fossil mesostigmatid mites are extremely rare.Inclusions assignable to the tortoise mites (Mesostigmata,Uropodina) are described here for the first time from Eo-cene (ca. 4449 Ma) Baltic amber. This is the oldest recordof Uropodina and documents the first unequivocal amberexamples potentially assignable to the extant genusUroobovella Berlese, 1903 (Uropodoidea: Urodinychidae). Further mites in the same amber pieces are tentativelyassigned to Microgynioidea (Microgyniina) and Ascidae(Gamasina), both potentially representing the oldest re-cords of their respective superfamily and family groups.This new material also preserves behavioural ecology in theform of phoretic deutonymphs attached to their carriers viaa characteristic anal pedicel. These deutonymphs in amberare intimately associated with longhorn beetles (Coleop-tera: Cerambycidae), probably belonging to the extinct
species Nothorhina granulicollis Zang, 1905. Modernuropodines have been recorded phoretic on species belong-ing to several beetle families, including records of livingUroobovella spp. occurring on longhorn beetles. Throughthese amber inclusions, a uropodinecerambycid associationcan now be dated back to at least the Eocene.
Keywords Parasitiformes . Eocene . Deutonymph .
Anal pedicel . Phoresy
Mites can be divided into two principal branches: Acariformesand Parasitiformes. The latter is further subdivided into fourclades (systematics after Krantz and Walter 2009), the mostspecies rich of which is the Mesostigmata (=Gamasida insome schemes) for whom Beaulieu et al. (2011) recognised11,424 living species. Despite this modern diversity and theirubiquity in soil habitats in particular, mesostigmatid miteshave a poor fossil record. Only four species have been for-mally described, plus some material often tentatively assignedto genera or families (Table 1; see also Discussion). Thisapparent rarity of fossil mesostigmatids remains a puzzle inarachnid palaeontology. It could be an artefact of ambers andother localities, not sampling enough of the soil fauna. Alter-natively, as we demonstrate here, specimens do exist but havenot been recognised or assigned correctly. Three principalclades of mesostigmatid mites are currently accepted: Sejida,Trigynaspida and Monogynaspida. The monogynaspidscan be further subdivided into various cohorts, includingMicrogyniina, Gamasina and Uropodina.
Uropodines are sometimes referred to as tortoise mites,although it should be stressed that this is a morphologicalcharacterisation referring to their often dome-like dorsalsurface, rather than a biological association with tortoises
Communicated by: Sven Thatje
J. A. Dunlop (*)Museum fr Naturkunde, Leibniz Institute for Researchon Evolution and Biodiversity at the HumboldtUniversity Berlin, Invalidenstrasse 43,10115 Berlin, Germanye-mail: Jason.Dunlop@mfn-berlin.de
J. KontschnPlant Protection Institute, Centre for Agricultural Research,Hungarian Academy of Sciences, P.O. Box 102,1525 Budapest, Hungarye-mail: firstname.lastname@example.org
J. KontschnDepartment of Zoology and Animal Ecology, Szent IstvnUniversity, Gdll, Pter Kroly str. 1,2100 Gyr, Hungary
M. ZwanzigScheiblerstrasse 26,12437 Berlin, Germanye-mail: email@example.com
Naturwissenschaften (2013) 100:337344DOI 10.1007/s00114-013-1031-8
Table 1 Overview of the 15currently valid species ofparasitiform mites known fromthe fossil record, plus furtherpublished assignments tofamilies and/or genera
For details and literature, seealso Dunlop et al. (2013)aA recent (i.e. living) species oftick also found as a fossil
No. Taxon Locality Stratigraphy Age (Ma)
OPILIOACARIDA (2 species)
1 Opilioacarus aenigmus Baltic amber Palaeogene (Eocene) 4449
2 Paracarus pristinus Baltic amber Palaeogene (Eocene) 4449
HOLOTHYRIDA (0 species)
No fossil record
IXODIDA (9 species)
3 Carios jerseyi New Jersey amber Cretaceous (Turonian) ca. 92
4 Ornithodoros antiquus Dominican amber Neogene (Miocene) ca. 16
5 Amblyomma cf. argentinaea Dominican amber Neogene (Miocene) ca. 16
6 Amblyomma cf. dissimilea Dominican amber Neogene (Miocene) ca. 16
7 Compluriscutata vetulum Myanmar amber Cretaceous (?Albian) ca. 100
8 Cornupalpatum burmanicum Myanmar amber Cretaceous (?Albian) ca. 100
9 Dermacentor cf. reticulatusa Galacia, Poland Subfossil
or turtles (Testudines). Uropodina are recognisable by areduction in the amount of setae on the legs and palps, aswell as modifications of the mouthparts and tritosternum(Lindquist et al. 2009). While the ecology of only a fewliving species is known in detail, a diversity of lifestyles hasbeen observed across the group (see Discussion). Manyoccur in dung or decaying organic matter where the adultsmay feed on nematodes and/or insect larvae. Numerousmesostigmatids show intimate associations with other ar-thropods (reviewed by Hunter and Rosario 1988). Amonguropodines, this manifests itself as phoresy; the mitehitching a ride on another arthropod in order to facilitateits distribution over a wider area and/or to reach a morefavourable habitat. Specifically, in uropodines, the immaturedeutonymph stage can secrete a stalk-like pedicel from itsanal pedicellar glands and uses this to attach itself to acarrier (Faasch and Schaller 1966; Faasch 1967; Athias-Binche and Evans 1981; Bajerlein and Boszyk 2004). Fora detailed modern account of this attachment mechanismand the associated gland structures, see Bajerlein andWitaliski (2012). A general summary of uropodine biologyand systematics can be found in Karg (1989).
Here, we describe the first formal records of the Uropodinafamily Urodinychidae (superfamily Uropodoidea) from Balticamber, based on deutonymphs in phoretic association withfossil longhorn beetles (Coleoptera: Cerambycidae). Othermites are found in the same amber pieces and are thus poten-tially associated with these beetles, too. They probably belongto two different cohorts: the superfamily Microgynioidea in theMicrogyniina and the family Ascidae in the Gamasina. In allcases, these are the oldest and, in the last two cases, the onlypalaeontological records of their respective (super) families.
Material and methods
Three pieces of Baltic amber were available for studycontaining mites associated with beetles. One of these (Fig. 1)stems is from the collection of one of the authors (MZ) andaccording to the original dealer originated from the Yantarnymine in the Kaliningrad province of the Russian Federation.This specimen has now been deposited in the palaeontologicalamber collections of theMuseum fr Naturkunde, Berlin, underthe repository number MB.A. 1879 (for Museum BerlinArthropoda). The second specimen (Fig. 2) was made availablefrom the private collection of Wolfgang Weitschat. It has alsonow been donated to the Berlin museum under the repositorynumber MB.A. 1900. A third specimen (not figured) camefrom the Geologische-Plaontologisches Institut und Museumin Hamburg (GPIH), no. 0425. For the latter two specimens,exact details of the original locality are not available. Fossilswere examined under a Leica MZ12s stereomicroscope andphotographed using a Nikon D700 digital camera with a series
of lenses. Multiple image stacks were combined into finalimages using the software package Combine ZP. All measure-ments are in micrometres.
Amber is difficult to date accurately, but Baltic am-ber is usually assigned to an Eocene (Lutetian) age ofabout 4449 Ma. The original amber forest has beeninterpreted as a warm temperate to subtropical environ-ment covering much of modern Fennoscandia and be-yond. For a recent overview and geological setting, seeWeitschat and Wichard (2010). Mite nomenclature andhigher taxon names are derived from Lindquist et al. (2009)and Beaulieu et al. (2011).
Order Parasitiformes Reuter, 1909Suborder Mesostigmata G. Canestrini, 1891Cohort Uropodina Kramer, 1881Superfamily Uropodoidea Kramer, 1881Family Urodinychidae Berlese, 1917Genus ?Uroobovella Berlese, 1903 sensu lato (Figs. 1 and 2)
Material, locality and horizon MB.A. 1879 (ex coll.Zwanzig) and 1900 (ex coll. Weitschat); GPIH 0425. Balticamber forest; Palaeogene, Eocene, Lutetian.
Description Small, shield-shaped deutonymphs have a max-imum length 460 and maximum width 300. Idiosoma is thusoval, ca. 1.5 times longer than being wide; colour, reddishbrown. Dorsal part of the body is covered by slightly domedholodorsal shield; ventral part, with sternal and ventral shields.Pedofossae are deep and well developed; legs are short andplaced on their respective pedofossae. Individual mites oftenattached to the carrier via a short, sometimes curved, analpedicel; maximum length is 220. MB.A. 1879 hosts the larg-est number of mites (Fig. 1); isolated deutonymphs hangventrally from the thorax or sit on the femur of the secondleg, with much greater concentrations of at least 20 individualsattached around the coxae of the second leg (near the thoraxabdomen junction) and at least 14 individuals on the thirdfrom the last sternite. In MB.A. 1900, a few deutonymphs areattached to the distal articles of the hindlegs. In GPIH 0425(not figured), three to four deutonymphs are attached to thetrochanter of leg 1 and the femur of leg 3.
Remarks The deutonymph fossils with the anal pedicel aretentatively assigned here to t