A new species of Phrynopus (Anura, Strabomantidae) … · A new species of Phrynopus (Anura, Strabomantidae) ... A new species of Phrynopus (Anura, Strabomantidae) from Peru ... the

Phyllomedusa - 7(1), September 2008

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A new species of Phrynopus (Anura, Strabomantidae)from Peru, with comments on the osteologyof the genusLinda Trueb1 and Edgar Lehr2

1 Division of Herpetology, Biodiversity Research Center, and Department of Ecology and Evolutionary Biology, TheUniversity of Kansas, Lawrence, Kansas 66045-7561, USA. E-mail: [email protected].

2 Staatliche Naturhistorische Sammlungen Dresden, Museum für Tierkunde, Königsbrücker Landstrasse 159, D-01109Dresden, Germany. E-mail: [email protected].

Received 4 June 2008.Accepted 1 July 2008.Distributed September 2008.

Phyllomedusa 7(1):11-24, 2008© 2008 Departamento de Ciências Biológicas - ESALQ - USP

ISSN 1519-1397

AbstractA new species of Phrynopus (Anura, Strabomantidae) from Peru, with commentson the osteology of the genus. A new, small species of Phrynopus is described fromthe eastern slopes of the Cordillera Oriental just north of the Río Huallaga in centralPeru. The species resembles P. montium, but is distinguished from it and othercongeners by its spatulate snout. The anterior end of the maxillary arcade is broadlyrounded in dorsal view, and composed of wide premaxillae that bear extraordinarilylarge alary processes that are deflected posteriorly at an acute angle. The configurationof the premaxillae accounts for the wide, depressed snout in this species, which inother osteological features resembles P. montium. The osteology of Phrynopusmontium is described in some detail in comparison to the new species, with theintention of establishing a baseline for future morphological studies and taxonomicdescriptions of strabomantine anurans of this and related genera.

Keywords: Anura, Strabomantidae, Strabomantinae, species description, Phrynopusmontium, osteology, Peru.

Introduction

In their revision of Brachycephalidae (sensuFrost et al. 2006), Hedges et al. (2008a) erecteda new taxon, Terrarana, for the 843 species ofNew World direct-developing frogs, of whichPhrynopus is one genus. Phrynopus is one of 16genera and 490 species placed in the largeSouth American subfamily Strabomantidae,

with the remaining South American taxa beingallocated to Brachycephalidae, and the WestIndian and Mesoamerican direct-developinganurans belonging to Eleutherodactylidae andCraugastoridae, respectively (Hedges et al.2008a).

Strabomantid frogs are arranged in twosubfamilies. Phrynopus belongs to the large,diverse Strabomantinae, which contains 465species and 10 genera distributed mainly innorthwestern South America, where it is mostdiverse in Andean regions of Colombia,Ecuador, and Peru. Strabomantines are distin-


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guished from members of its smaller sistergroup, Holoadeninae (25 species in 6 genera),by the narrow terminal digits on the fingers andtoes, and the usual absence of circumferentialgrooves in holoadenines. Strabomantinesusually have expanded terminal digits andcircumferential grooves. These morphologicaldifferences are not especially trenchantcharacters to distinguish among members of thisspeciose, widely distributed, and phenotypicallychallenging anuran clade; thus, it is hardlysurprising that occasionally, molecular data arerequired for unequivocal allocation tosubfamily, especially in the absence of compa-rative morphological data.

An unintended consequence of this majorreorganization of direct-developing frogs is thatwe must reassess our morphological knowledgeof the group, owing to the rearrangement oftaxa. Phrynopus is a case in point. Currently, 21species are recognized—auriculatus, ayacucho,barthlenae, bracki, bufoides, dagmarae,heimorum, horstpauli, juninenesis, kauneorum,kotosh, miroslawae, montium, nicoleae,oblivius, paucari, peruanus, pesantesi,tautzorum, tribulosus, and thompsoni (Chaparroet al. 2008, Hedges et al. 2008a). Severalspecies formerly placed in Phrynopus weretransferred to other genera. Among these are:bagrecito (Psychrophrynella), brunneus(Hypodactylus), columbianus (Niceforoniacolumbiana), cophites (Bryophryne), elasso-discus (Hypodactylus), fallaciosus (Hypo-dactylus), flavomaculatus (Lynchius), laplacai(synonym of wettsteini), lucida (Hypodactylus),nanus (Niceforonia nana) , nebulanastes(Lynchius), nigrovittatus (Hypodactylus),parkeri (Lynchius), peraccai (Hypodactylus),pereger (Oreobates), peruvianus (part =Noblella peruviana; part = Psychrophrynella sp.nov.), spectabilis (synonym of Pleurodemamarmorata), simonsii (Pristimantis), andwettsteini (Psychrophrynella). Osteologicalcharacters have figured significantly intaxonomic studies of Phrynopus and allied taxabeginning with Lynch’s (1971) seminal work on

leptodactylid frogs. Table 1 summarizescontributions to our osteological knowledge ofthese taxa (sensu lato) by Lynch (1971, 1975,1986) and Cannatella (1984). Of the 18 speciesof Phrynopus listed as having been described orfigured in previous publications, only three areretained in the genus today—Phrynopusperuanus, the type species of the genus, and P.dagmarae and P. kauneorum, two speciesrecently described by Lehr et al. (2002a,b).Lynch (1975) provided a drawing of part of thepectoral girdle of the type species, P. peruanus.Lynch (1975) also provided illustrations of thebony skull for one other taxon, Niceforoniamontia, which now is placed in Phrynopus.Thus, the irony of our osteological knowledgeof Phrynopus is that we seemed to have arelatively firm grasp on it 30 years ago; however,today, we have available three renderings of thebony skull of one taxon, Phrynopus montium, adrawing of a portion of the pectoral girdle of thetype species, P. peruanus, and drawings of thedentigerous processes of the vomers of P.dagmarae and P. kauneorum and the terminalphalanges of P. kauneorum.

Many collections contain undescribedspecies, and as Hedges et al. (2008a) observed,“… their analyses and resulting classificationmust be regarded as an initial effort waiting tobe expanded and refined.” Herein, wesupplement their classification with thedescription of a new species of strabomantidanuran of the genus Phrynopus from Peru. Thespecies was discovered in the collections ofLouisiana State University Museum of NaturalScience and is distinguished from all otherPhrynopus by its unusually broad, sloping snoutsupported by an unusual configuration of themaxilla and premaxilla.

Materials and Methods

The taxonomy of strabomantid frogsfollows that of Hedges et al. (2008a,b). Theterminology specific to these anurans isadopted from Lynch and Duellman (1997)

Trueb and Lehr


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Table 1 - Summary of osteological data published in association with the generic name Phrynopus, with the currenttaxonomic status of the taxon noted. Taxa denoted with an asterisk are included in the strabomantid subfamilyHoloadeninae, whereas all others are included in Strabomantinae (Hedges et al. 2008a).

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A new species of Phrynopus (Anura, Strabomantidae) from Peru


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except that the term “dentigerous processes ofvomers” is used instead of “vomerineodontophores.” We follow the definitions ofconditions of the tympanum by Lynch andDuellman (1997); the otic region wasdissected in order to evaluate the condition ofthe tympanic annulus. Specimens weremeasured with digital calipers to thenearest 0.1 mm and include the followingmeasurements: SVL (snout–vent length), tibialength, foot length (distance from proximalmargin of inner metatarsal tubercle to tip ofToe IV), head length (from angle of jaw to tipof snout), head width (at level of angle ofjaw), eye diameter, IOD (interorbitaldistance), upper eyelid width, internarialdistance, and eye–nostril distance (straight-line distance between anterior corner of orbitand posterior margin of external naris).

Comparative lengths of Toes III and V weredetermined when both were adpressed againstToe IV; lengths of Fingers I and II wereestimated when adpressed against each other.Drawings were made with a stereomicroscopeequipped with a camera lucida. Osteologicaldata were gathered from radiographs of the newtaxon, and comparisons were made with acleared-and-stained congener, Phrynopusmontium. Specimens were submerged in ethanolor isopropanol and photographed. Codes formuseum collections are: KU = Natural HistoryMuseum, University of Kansas; LSUMZ =Louisiana State University, Museum of NaturalScience; MHNSM = Museo de Historia Natural,Universidad Nacional Mayor de San Marcos;MTD = Museum für Tierkunde, Staatliche Natur-historische Sammlungen Dresden. Comparativespecimens examined are listed in Appendix I.

Species Description

Phrynopus lechriorhynchus sp. nov.(Figures 1–6)

Holotype - LSUMZ 31886 (Figure 1), anadult male from Punta de Esperanza on trail to

Huaylaspampa, above Acomayo, Departamentode Huánuco, Peru, obtained by Ted Parker inJanuary 1975.

Paratype - LSUMZ 32308, juvenile from SHualayspampa, Bosque Cutirragra ca. 2744 m(= 9100 feet), 18 July 1973, obtained by D. A.Tallman.

Etymology - The specific epithet is derivedfrom the Greek adjective lechrios, meaning“slanting,” and the Greek noun rhynchos,meaning nose, in reference to the broad,spatulate snout and rostrum of this small frog.

Diagnosis - A strabomantid anurandistinguished by the following combination ofcharacters: (1) Skin on dorsum finely shagreen;dorsolateral folds absent; skin on venter weaklyareolate; discoidal fold absent; (2) tympanicmembrane and tympanic annulus absent; (3)snout spatulate, long and depressed, broadlyrounded in dorsal profile and sloping in lateralview; (4) upper eyelid without tubercles; uppereyelid width narrower than IOD; cranial crestsabsent; (5) dentigerous processes of vomerssmall, oblique; (6) males lacking vocal slits andnuptial pads; (7) Finger I shorter than Finger II;discs on fingers slightly expanded, marginalgroove not discernable except on Finger III; (8)fingers without lateral fringes; (9) ulnar andtarsal tubercles absent; (10) heel lackingtubercles; inner tarsal fold present; (11) innermetatarsal tubercle ovoid, slightly larger thansubconical outer metatarsal tubercle, elevated,slightly conical in lateral view; supernumeraryplantar tubercles absent; (12) toes withoutlateral fringes; toe webbing absent; Toe Vslightly shorter than Toe III; toe discs slightlysmaller than those on fingers, marginal groovenot discernable; (13) in preservative, dorsummottled tan and brown with a white middorsalstripe, belly and chest tan with dark brownflecks, throat tan with a white middorsal stripeand minute brown spots; (14) SVL in singlemale 16.6 mm.

As discussed above, Phrynopus lechriorhyn-chus is most likely to be confused with one of

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depressed (acuminate vs. blunt) in profile andthe nostril is located about midway between ante-rior margin of the eye and the end of the snout(Figure 2A, B). Phrynopus lechriorhynchus alsomight be confused with male Hypodactylusnigrovittatus, which bear a fleshy protuberanceon the end of the snout (Figure 2C, D). However,the snout in H. nigrovittatus is pointed, ratherthan broadly rounded, in dorsal view, and theprotuberance, which is present only in males,lacks underlying skeletal support that is presentin P. lechriorhynchus and described below.

Description of the holotype - Head as wideas body, slightly longer than wide (Figure 1);head width 36.1% SVL; head length 37.4%SVL; snout long and depressed, broadlyrounded in dorsal view and sloping antero-ventrally in lateral view (Figure 2A, B); top ofhead between eyes and nares slightly concave;

the smaller species of Phrynopus, with which itshares a number of common external features.However, no other known Phrynopus possessessuch a distinctly spatulate snout as does P.lechriorhynchus; the snout of this species is

Figure 1 - Holotype of Phrynopus lechriorhynchus(LSUMZ 31886) in lateral (A), dorsal (B), andventral (C) views. Photos by E. Lehr.

Figure 2 - Head of Phrynopus lechriorhynchus (holotype;LSUMZ 31886) in lateral (A), and dorsal (B)views. Note position of naris, which is locatedabout midway between end of snout and ante-rior margin of eye. Lateral (C) and dorsal (D)views of head of male Hypodactylusnigrovittatus (KU 222017, male, 19.8 mmSVL), which bears a fleshy protuberance at theend of the snout. Note position of naris, whichis closer to end of snout than it is to anteriormargin of eye. Drawings by E. Lehr.



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eye diameter 150% eye–nostril distance; nostrilsslightly protuberant, directed dorsolaterally;canthus rostralis straight in dorsal view, broadlyrounded in section; loreal region concave; lipsrounded; upper eyelid flat (artifact ofpreservation?), without tubercles; upper eyelidwidth 52.6% interorbital distance; tympanicmembrane and annulus absent; supratympanicfold not distinct; two low, slightly enlargedpost-rictal tubercles on each side of head.Choanae small, ovoid, not concealed by palatalshelf of maxilla; dentigerous processes ofvomers thin, widely separated, situatedposteromedial to choanae; each vomer bearingbarely visible teeth in an oblique row; tongue1.5× as long as wide, not notched behind, freeposteriorly for half of its length.

Skin on dorsum finely shagreen with smalltubercles dorsolaterally; dorsolateral foldsabsent (Figure 1); skin on flanks with smalltubercles; skin on thighs, belly, chest, and throatweakly areolate, skin on other ventral surfacessmooth; discoidal fold absent; cloacal sheathshort; large tubercles absent in cloacal region.Ulnar tubercles absent (Figure 3A); palmartubercles slightly elevated, outer palmartubercle bifid, approximately 2× the size ofovoid, thenar tubercle; subarticular tuberclesindistinct; fingers without lateral fringes; FingerI shorter than Finger II; discs on fingers narrow;marginal grooves absent (Figure 3A).

Hind limbs slender, tibia length 40.4% SVL;foot length 39.8% SVL; upper surfaces of hindlimbs weakly tuberculate; posterior and ventralsurfaces of thighs weakly areolate; heel withouttubercles; tarsus without tubercles or fold; innermetatarsal tubercle elevated, ovoid, about twiceas large as round outer metatarsal tubercle(Figure 3B); plantar supernumerary tuberclesindistinct; subarticular tubercles rounded, flat;toes without lateral fringes; webbing absent;Toe V slightly shorter than Toe III; discs ontoes narrow, marginal groove absent; relativelengths of toes: 1 < 2 < 3 < 5 < 4.

Measurements (in mm) of holotype: SVL 16.6;tibia length 6.7; foot length 6.6; head length 6.2;

head width 6.0; diameter of eye 1.8; interorbitaldistance; 1.9; width of upper eyelid 1.0; internarialdistance 2.0; eye–nostril distance 1.2.

Coloration of holotype in preservative -Dorsum mottled tan and brown with narrow

white middorsal stripe from snout to cloaca;arms and legs mottled tan and brown; margin ofupper lip with cream flecks separated by brownflecks; canthal and supratympanic stripes darkbrown; flanks colored as dorsum but slightlydarker; groin mottled tan and dark brown;anterior surface of thighs dark brown with fewtan flecks; posterior surface of thighs darkbrown, close to knee bend with three ovoid,white blotches on each side; concealed surfacesof shanks dark brown with irregularly shapedwhite blotches; belly and chest tan with darkbrown flecks, throat tan with a white middorsal

Figure 3 - Hand (A) and foot (B) of holotype ofPhrynopus lechriorhynchus (holotype, LSUMZ31886). Drawings by E. Lehr.

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stripe and minute brown spots; iris gray.Coloration of holotype in life unknown.

Variation - The single paratype is ajuvenile in which the spatulate snout is notobviously developed; in other respects, the frogis morphologically identical to the holotype.Tuberculation of the ventral surfaces of thehand and feet is more distinct, probably becauseit is better preserved. The upper eyelid bearssmall tubercles. A marginal groove is visible onFinger III. The dorsum is brown with a whitemiddorsal stripe bordered on both sides by darkbrown extending from the tip of snout to cloaca;a broad, pale gray dorsolateral stripe extendsfrom the posterior eyelid to insertion of legs. Amidventral stripe runs from tip of lower lip tothe posterior surfaces of thighs. A white stripeextends from the ventral surface of each armacross the chest, and another white stripeextends from the cloaca diagonally to proximaledge of posterior surface of each thigh.

Distribution - This species is known fromtwo localities at elevations of 2740–2800 m onthe eastern slopes of the Cordillera Oriental justnorth of the Río Huallaga in central Peru.Presumably, it occurs in remnants of humidmontane forest.

Osteology - Cranium. The skull width isabout equal to its length, and the greatest widthis at the level of the articulation of the maxillaand quadratojugal at the posterior level of theoptic fenestra and orbit (Figures 4, 5). Theposterior end of the upper jaw lies anterior tothe fenestra ovalis at the anterior corner of theotic capsule. The braincase is broad, nearly one-third the greatest width of the skull. The oticcapsules are quadrangular, completely ossifieddorsally with well-developed epiotic eminences;the anterior epiotic eminence is about 30%longer than the posterior. The crista parotica iscartilaginous except for a small, ossified portionadjacent to the anterolateral corner of the oticcapsule. The endocranial cartilage of the

exoccipital and prootic regions of the braincaseseems to be completely mineralized. Theoccipital condyles are widely separated andstalked. Dorsally, the paired parietal fontanellesare separated from one another by the taeniatecti medialis and from the large frontal fonta-nelle by the taenia tecti transversalis. Thebraincase is roofed by paired frontopairetalbones, the limits of which cannot be distinguishedin the radiographs; likewise, the shape of thenasals is difficult to determine. Ventrally, alarge prootic foramen and small oculomotorforamen are visible in the prootic. The sphen-ethmoid is complete dorsally and ventrally. Inventral and lateral views, its posterior margincan be seen to lie at about the midlevel of theorbit. The sphenethmoid contributes to theposterior walls of the olfactory capsule, andextends about one-third the distance lateraltoward the maxilla. The rostrum (i.e., that partof the cranium anterior to the braincase) isextraordinarily large in this species, accountingfor nearly 30% the length of the skull. However,close examination of the radiographs reveals apeculiarity. The olfactory capsules occupy onlythe posterior two thirds of this space. Theanterior end of the snout is composed of broadpremaxillae that bear large alary processes thatare deflected at a steep posterior angle (Figure 4).

The maxillary arcade is complete, but thearticulation between the maxilla and quadra-tojugal is weak (Figure 4). Teeth are present onthe maxillae and premaxillae. A moderatepalatal shelf is evident on the maxilla. Thepremaxilla is distinguished by extraordinarilyhypertrophied medial palatine processes andlateral palatine processes. These processes,together with the broadly splayed alary processconfigure the premaxilla, which forms aterminal rostral bone that lies anterior to theolfactory capsule on each side (Figures 4, 5).The maxilla bears a well-developed pars facialisanterior to the orbit that covers the lateral aspectof the olfactory capsule. The pterygoid is welldeveloped with a slender, approximatelystraight anterior ramus that parallels the



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Figure 5 - Cranial osteology of Phrynopus montium (KU 206652, female, 24.2 mm SVL). Dorsal (A), ventral (B), andlateral (C) views of skull. (D) Ventral aspect of mandible and hyoid apparatus. Bones are stippled and cartilageis shown in gray. Cranial morphology resembles that of P. lechriorhynchus. However the snout is less spatulate;the premaxillae are slightly narrower, and the alary processes of premaxilla are smaller and not deflectedposteriorly at such a great angle as in P. lechriorhynchus.



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braincase. The medial ramus of the pterygoidabuts the anterolateral margin of the oticcapsule ventrally and is approximately the samelength as the more slender posterolateral ramusof the bone. The squamosal is surprisingly welldeveloped; the otic ramus caps the lateralmargin of the crista parotica and the zygomaticramus is a short, blunt blade extending aboutone-quarter the way to the maxilla. The ventralramus is stout, completely investing the lateralaspect of the palatoquadrate.

The parasphenoid is robust. The width of thecultriform process is about one-third that of thebraincase; the process tapers slightly anteriorlyand its anterior terminus is broadly separatedfrom the anterior margin of the orbit. Theposterolateral alae are broad, completelyflooring the otic capsules, but the exact limitsare difficult to determine owing to synostosis. Atympanic annulus is absent, as is the plectralapparatus; however, a cartilaginous operculumlies in the fenestra ovalis.

The anterior palatal region is distinguishedby well-developed neopalatines, anteriorossification of the sphenethmoid in the olfactoryregion, and elimination of vomerine dentition.The vomers are present as flat palatal bones, butlack dentigerous processes (Figure 5B).

Axial column. The vertebral column iscomposed of eight procoelous presacralvertebrae (Figure 4). The transverse processesof Prescrals II and III are slightly expandeddistally; those of Presacral II are orientedanterolaterally, whereas those of III are slightlycurved and lateral in orientation. The relativesizes (overall width) of the vertebral elements isas follows: I < VI = VII = VIII < V < II < IV =sacrum < III. The sacral diapophyses arenarrowly expanded, with the distal width beingonly about twice that of the base. The leadingedge of the diapophysis is straight and formsnearly a right angle with the longitudinal axis ofthe body, whereas the posterior margin iscurved and describes an acute angle with thebody axis. The sacrum has a bicondylar

articulation with the urostyle, which bears asimple dorsal flange.

Pectoral girdle. Although the pectoralgirdle clearly is arciferal in origin, it seems tobe functionally firmisternal (Figure 6). Theclavicle is moderately robust and uniform inwidth along the procoracoid cartilage (Figure4). The medial ends of the clavicles are bluntand distinctly separated from one another. Themedial arms of the clavicles are slightlyconcave and oriented anteromedially such thattheir tips lie at a level slightly anterior to that ofthe lateral head of the fused clavicle and parsacromialis of the scapula. The omosternum is aslender spindle of cartilage (Figures 4, 6). Theclavicle seems to be synostotically united withthe coracoid by means of mineralization of theprocoracoid cartilage in the region of theglenoid fossa. The coracoid is a robust bone.The width of the bone at the glenoid cavity isabout 1.5× that of the midshaft width, whereasthat at the sternal end is more than 2× themidshaft width; the length of the bone is abouttwice the width at the sternal end. The parsacromialis of the scapula is fused to the clavicleand separated by a distinct cleft from the parsglenoidalis. Both the anterior and posteriormargins of the scapula are broadly concave; theslender midshaft width is only about half thewidth of the dorsal scapular margin, which in

Figure 6 - Pectoral girdle of Phrynopus montium (KU206652, female, 24.2 mm SVL) in ventralview. The scapula and suprascapula have beendeflected into the ventral plane for thepurposes of illustration. Bones are stippled andcartilage is shown in gray.

Trueb and Lehr


21

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22

turn, is narrower than the ventral portion of thebone. The suprascapula is narrow, with thedorsal margin being only about 30% broaderthan the ventral margin. The cleithrum isevident as a narrow band of bone along theanterior margin that grades into mineralizationof the suprascapular cartilage posteroventrally.

Discussion

The results of molecular studies (Hedges etal. 2008a,b) reveal that Phrynopus is a memberof a clade composed of 10 genera with a centerof diversity in northwestern South America. Theosteological characters that have been used todiagnose these taxa are listed in Table 2.Phrynopus is one of four genera that possessesknob-shaped terminal phalanges, the othersbeing Lynchius, Niceforonia, and Oreobates.Based on the generalized and miscellaneousosteological characters listed in this table,Phrynopus is not clearly distinct fromNiceforonia. It differs from Lynchius primarilyin the relative lengths of Fingers I and II, andfrom Oreobates in the relative lengths ofFingers I and II, and III and V.

Published illustrations of the skulls ofLynchius flavomaculatus and L. parkeri (Lynch1975: figs. 9, 10), and L. nebulanastes (Cannatella1984: fig. 4, right) permit us to identify charactersthat distinguish Lynchius and Phrynopus. Theskulls of Lynchius are robust and much wider thanlong (length 86% width in flavomaculatus andparkeri; 84% in nebulanastes), whereas those ofPhrynopus are about equal in width and length.All of these species have well-ossified skulls withlarge nasals that overlap the ossified sphenethmoidand articulate with one another medially orare narrowly separated (nebulanastes) andthat cover most of the lateral portion of theolfactory capsule, whereas the nasals are muchsmaller in Phrynopus. The frontoparietals arelarge, articulated medially or narrowly separated(nebulanastes), and exostosed in L. flavoma-culatus; they are similar in Phrynopus, but showno tendency toward exostosis.

In both Lynchius and Phrynopus, the oticcapsules are well ossified and synostoticallyunited with the cristae paroticae. The squamosalarticulates with the crista parotica in eachspecies except nebulanastes, in which it isnarrowly separated from the bony crista, as it isin Phrynopus. Lynchius nebulanastes differsfrom its congeners and Phrynopus in havingincomplete ossification of the exoccipital; thereare gaps in the ossification dorso- andventromedially, as well as along the posteriorepiotic eminence at the union of the exoccipitaland prootic. Neither Lynch (1975) norCannatella (1984) illustrated the plectralcomplex; so, nothing can be added about this.

The maxillary arcades of Lynchius andPhrynopus differ significantly, although in bothgenera they are dentate and robust, bearingwell-developed facial flanges and stoutquadratojugals. In Lynchius, the alary processesof the premaxillae are more or less vertical,whereas in Phrynopus, they are deflectedposteriorly. The mandible is long, with theangle of the jaw lying at about the level of thefenestra ovalis or slightly posterior to it inLynchius; a transverse line projected across adorsal view of the skull at the level of the angleof the jaw would transect the posterior epioticeminence in Lynchius, whereas the same metricin Phrynopus would transect the anterior epioticeminence. The maxillae bear moderately welldeveloped palatal shelves in both genera, andthe premaxillae are characterized by extraor-dinarily large medial and lateral palatineprocesses (condition unknown in L. flavoma-culatus). (Alternately, some authors mightdescribe this condition as an extraordinarilywide palatal shelf that is deeply incised.) Thesizes of these palatal components of thepremaxilla seem more exaggerated inPhrynopus, perhaps by comparison with therelatively more delicate pars palatina of theadjacent maxilla in this genus than in Lynchius.

The dentate vomers of Lynchius are welldeveloped in parkeri and nebulanastes, with theposterior parts of the vomers lying at the level

Trueb and Lehr


23

of the neopalatines and anterior end of thecultriform process of the parasphenoid.Phrynopus, in contrast, lacks dentigerousprocesses of the vomers, although the posteriorvomerine processes terminate adjacent to theneopalatines. The cultriform process of Phrynopusis much shorter than that of L. parkeri and L.nebulanastes, in which the anterior terminus ofthis bone lies at the anterior margin of the orbit atthe level of the neopalatines. In both of the latterspecies, the cultriform process is narrower at itsbase than it is at mid-orbit; anteriorly, it graduallytapers in width. The pterygoid is robust in bothLynchius and Phrynopus, with the anterior ramusarticulating with the maxilla in the anterior part ofthe orbit.

Lynch (1971: fig. 104) provided the firstillustrations of the skull of Phrynopus montium inhis account of Niceforonia montia; these drawingsare based on specimens stained only for bone andthus, are supplemented herein with drawings of aspecimen showing cartilage and bone. The latter,of course, provides more information about agreater range of body parts, but there isremarkable parity in our observations of the bonyelements of the skull. We see a slightly greaterposterior deflection of the alary processes of thepremaxillae, a somewhat different shape of thepars facialis of the maxilla, a shorter maxillaryarcade, and a less robust quadratojugal than Lynchillustrated; the length the upper jaw and even thedeflection of the alary processes (in dorsal view)can be a function of the tilt of the plane in whichthe specimen is viewed. We suspect that thisaccounts for the discrepancy because the length ofthe maxillary arcade appears significantly shorterin his ventral view of the same specimen than itdoes in his dorsal view. We also think that hesimplified his interpretation of the neopalatines orcould not distinguish them from the underlyingcartilage in the region of the planum antorbitale.

Lynch (1975) redescribed Phrynopusperuanus, the type species of the genus, andprovided drawing of the zonal elements of thepectoral girdle based on a dissection of apreserved specimen. Based on his illustration

(Lynch 1975: fig. 13), P. peruanus has anarciferal girdle with broadly overlappingepicoracoid cartilages. The coracoid is a short,stout element that is slightly wider at is glenoidend than its sternal end; the coracoids arebroadly separated from one another by a widthequivalent to the length of the coracoid bone. Incontrast, in the girdles of P. montium and P.lechriorhynchus, the epicoracoid areas arenarrower, and coracoids longer; in P. montium,it is possible to discern that the epicoracoids arepartially fused to one another medially. Lynchdepicts a simple, broad sternum with ashallowly notched posterior margin for P.peruanus. The sternum of Phrynopus montium,in contrast, has lateral notches and a curvedposterior margin. All three taxa have simple,spindle-like cartilaginous omosterna and robustclavicles, with the medial tips of the claviculararms lying anterior to the level of the fusedheads of the clavicle and pars acromialis of thescapula.

As morphologists and taxonomists, it isgratifying to note that the extensivereorganization based on molecular data of thesespeciose and often troublesome anurans hasyielded an arrangement that seems to makesense—at least for the few taxa about which weknow something osteologically. Thus, amongthe knob-fingered genera, Lynchius can bedistinguished from Phrynopus, and both genera,in turn, seem to have combinations of featuresthat may prove to distinguish them from othergenera. Although it is more difficult to gatherdata about bones, they have fascinatingfunctional and evolutionary stories to tell. It ishoped that the information provided in Tables 1and 2, along with the results of this paper, willencourage other evolutionary biologists toinvestigate the osteological diversity ofstrabomantid anurans.

Acknowledgments

We are grateful to W. E. Duellman for histhoughtful commentary on a preliminary draft



24

of this manuscript. Specimens were kindlyloaned by Chris Austin (LSUMZ), and JohnWoodward (MCZ) and Andrew Campbell (KU)provided radiographs of specimens. Lehr’sresearch was supported by a postdoctoral grantfrom the Alexander von Humboldt-Foundation,a DFG grant, and an Ernst Mayr Grant providedby the Museum of Comparative Zoology. Trueb’sresearch was supported by a grant from theNational Science Foundation, EF–0334928.

References

Cannatella, D. C. 1984. Two new species of the leptodactylidfrog genus Phrynopus, with comments on the phylogenyof the genus. Occasional Papers of the Museum ofNatural History, The University of Kansas 113: 1–16.

Chaparro, J. C., J. M. Padial and I. De la Riva. 2008. Twosympatric new species of Phrynopus (Anura:Strabomantidae) from Yanachaga Chemillén NationalPark (central Peruvian Andes). Zootaxa 1761: 49–58.

Frost, D. R., T. Grant, J. Faivovich, R. H. Bain, A. Haas,C. F. B. Haddad, R. O. de Sá, A. Channing, M.Wilkinson, S. C. Donnellan, C. J. Raxworthy, J. A.Campbell, B. L. Blotto, P. Moler, R. C. Drewes, R.A. Nussbaum, J. D. Lynch, D. M. Green, and W. C.Wheeler. 2006. The amphibian tree of life. Bulletin ofthe American Museum of Natural History 297: 1–371.

Hedges, S. B., W. E. Duellman and M. P. Heinicke. 2008a.New World direct-developing frogs (Anura:Terrarana): molecular phylogeny, classification,biogeography, and conservation. Zootaxa 1737: 1–182.

Hedges, S. B., W. E. Duellman and M. P. Heinicke. 2008b.A replacement name for Isodactylus. Zootaxa 1795:67–68.

Lehr, E., C. Aguilar and G. Köhler. 2002a. Two sympatricnew species of Phrynopus (Anura: Leptodactylidae)from a cloud forest in the Peruvian Andes. Journal ofHerpetology 36: 208–216.

Lehr, E., C. Aguilar and J. H. Córdova. 2002b.Morphological and ecological remarks on Phynopuskauneorum (Amphibia, Anura, Leptodactylidae).Zoologische Abhandlungen Museum für TierkundeDresden 52: 71–75.

Lynch, J. D. 1971. Evolutionary relationships, osteology,and zoogeography of leptodactyloid frogs. Universityof Kansas Museum of Natural History MiscellaneousPublication 53: 1–238.

Lynch, J. D. 1975. A review of the Andean leptodactylidfrog genus Phrynopus. Occasional Papers of theMuseum of Natural History, The University of Kansas35: 1–51.

Lynch, J. D. 1986. New species of minute leptodactylidfrogs from the Andes of Ecuador and Peru. Journal ofHerpetology 20: 423–431.

Lynch, J. D. and W. E. Duellman. 1997. Frogs of the genusEleutherodactylus in western Ecuador. Systematics,ecology, and biogeography. The University of KansasNatural History Museum Special Publication 23: 1–236.

Appendix I – Comparative Material Examined

Hypodactylus nigrovittatus: ECUADOR: NAPO: S slope Cordillera del Due above Río Coca, 1150 m:KU 123503–42, 123544–65. PERU: LORETO: jct. Río Sucusari & Río Napo: KU 220354; jct. RíoYanamono & Río Amazonas: KU 220355, KU 220447–48; San Jacinto, 175–190 m: KU 22017–18;1.5 km N Teniente López, 310-340 m: KU 222019–20.

Noblella duellmani: PERU: PASCO: Cillapata (approximately 1.5 km NNE Auquimarca), 2900 m:MHNSM 19856 (holotype).

Phrynopus montium: PERU: JUNÍN: Monaynioc, 72 km NE Tarma, 3660 m: KU 206650–52.

Pristimantis cruciocularis: PERU: JUNÍN: Pampa Hermosa, 1540 m: MHNSM 18685 (holotype).

Pristimantis flavobracatus: PERU: Pasco: Km 34 on road from Oxapampa to Yaupi, 1770 m:MHNSM 19871.

Pristimantis rhabdocnemus: PERU: PASCO: 2.9 km N and 5.5 km E (airline) of Oxapampa, 2600 m:KU 291646 (holotype), 291651 (paratype), 291647–291650, 291652–291656.

Trueb and Lehr

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