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A new and unusual procolophonid parareptile from the Lower of South Sean P. Modesto a; Diane M. Scott b; Jennifer Botha-Brink cd;Robert R. Reisz b a Department of Biology, Cape Breton University, Sydney, Nova Scotia, Canada b Department of Biology, University of Toronto in Mississauga, Mississauga, Ontario, Canada c Palaeontology, National Museum, Bloemfontein, d Department of Zoology and Entomology, University of the Free State, Bloemfontein, South Africa

Online publication date: 19 May 2010

To cite this Article Modesto, Sean P. , Scott, Diane M. , Botha-Brink, Jennifer andReisz, Robert R.(2010) 'A new and unusual procolophonid parareptile from the Lower Triassic Katberg Formation of South Africa', Journal of Vertebrate Paleontology, 30: 3, 715 — 723 To link to this Article: DOI: 10.1080/02724631003758003 URL: http://dx.doi.org/10.1080/02724631003758003

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ARTICLE

A NEW AND UNUSUAL PROCOLOPHONID PARAREPTILE FROM THE LOWER TRIASSIC KATBERG FORMATION OF SOUTH AFRICA

SEAN P. MODESTO,*,1 DIANE M. SCOTT,2 JENNIFER BOTHA-BRINK,3 and ROBERT R. REISZ2 1Department of Biology, Cape Breton University, Sydney, Nova Scotia, B1P 6L2, Canada, sean [email protected]; 2Department of Biology, University of Toronto in Mississauga, 3359 Mississauga Road, Mississauga, Ontario, L5L 1C6, Canada, [email protected]; 3Karoo Palaeontology, National Museum, P.O. Box 266, Bloemfontein 9300, South Africa; Department of Zoology and Entomology, University of the Free State, Bloemfontein, 9300, South Africa, [email protected]

ABSTRACT—A small collected from the base of the Katberg Formation of South Africa represents a new Early Tri- assic procolophonid parareptile. Phonodus dutoitorum, gen. et sp. nov., is diagnosed by a roughly straight ventral temporal margin, prefrontals that contact each other along the dorsal midline, presence of a large posterior maxillary tooth, an eden- tulous pterygoid, a reduced transverse flange of the pterygoid, and other . A cladistic analysis identifies P. dutoitorum as a member of the procolophonid Leptopleuroninae. The presence of large maxillary teeth, their po- sitioning ventral to strongly developed antorbital buttresses, and the loss of the ventral temporal emargination are suggestive of a durophagous diet. Phonodus dutoitorum is recognized as the oldest known leptopleuronine. Optimization of geographic distributions onto procolophonid phylogeny indicates that the presence of P. dutoitorum in the Karoo Basin of South Africa is explained most parsimoniously as the result of migration from Laurasia. Phonodus dutoitorum is the fifth procolophonoid to be described from the of the Karoo Basin, providing further support for the hypothesis that procolophonoid evolution was not greatly perturbed by the end- event.

INTRODUCTION phonid , and discuss its implications for procolophonid evolution. Parareptiles were the most taxonomically and ecologically di- Institutional Abbreviation—NM, National Museum, Bloem- verse at the end of the Paleozoic Era, but were eclipsed fontein. by eureptiles following the end-Permian mass extinction of 252 million years ago (Mundil et al., 2004). Procolophonoids are the only parareptiles that survived this extinction event, and phyloge- netic studies suggest that they experienced a reduced extinction GEOLOGICAL SETTING level (Modesto et al., 2001, 2003) compared to other . Recent field work in South Africa (Botha et al., 2007) indicates The skull described in this paper (NMQR 3564) was collected that procolophonoids of the earliest Triassic (Induan) appear to as part of a small block of conglomerate found ex situ atop Downloaded By: [Botha-Brink, Jennifer] At: 06:14 20 May 2010 have flourished in the wake of the Mother of Mass the first major sandstone exposed on the Northern Cape farm (sensu Erwin, 1993). Indeed, procolophonoid are often lo- Bergendal. The block appeared to have been ‘calved’ from a cally abundant where they are present (Kitching, 1977; Li, 1983; sandstone layer that lies less than 1 m above the lowermost sand- Botha et al., 2007). stone. Collecting at the locality yielded numerous specimens of In the course of field work in the Lower Triassic the Lystrosaurus attributable to L. murrayi and possibly Assemblage Zone, Karoo Basin of South Africa, the authors col- L. declivis, and a single specimen of a small therocephalian at- lected the skull of a small in a block of intraforma- tributable to Tetracynodon darti (NMQR 3597). The specimens tional conglomerate from the Lower Triassic Katberg Forma- of the former genus indicate that the Lystrosaurus Assemblage tion on the Northern Cape farm Bergendal. Little more than the Zone (AZ) broadly crops out on Bergendal. Tetracynodon darti weathered tips of the transverse flanges, quadrate condyles, and is known from Lystrosaurus-AZ localities in both the northern the alveolar regions of the maxillae were exposed in ventral as- and southern portions of the Karoo Basin: the holotype is from pect. Mechanical preparation revealed the skull of a small rep- the farm New Castle (formerly an annex of the farm Admiralty tile of unusual morphology, one characterized by a large tooth Estates) in KwaZulu-Natal Province (Sigogneau, 1963; Kitching, in each maxilla, a palate with edentulous palatines and ptery- 1977), for which an exact placement of the fossiliferous strata goids, a reduced transverse flange of the palate, and the pres- in the Lystrosaurus AZ has not been determined. All referred ence of a small lateral temporal opening. Although most of the specimens of T. darti have been collected from localities in the skull table, the braincase, and the mandible are missing, the southern part of the Karoo Basin, and have been positioned in specimen preserves a suite of apomorphies that, among Permo- the Triassic portion of the Palingkloof Member of the Balfour Triassic reptiles, is known only in procolophonids. We describe Formation (Damiani et al., 2004; Botha and Smith, 2006). The the Bergendal specimen as a new genus and species of procolo- specimen of T. darti collected at Bergendal was found in situ approximately 1 m below the first major sandstone. We infer that this sandstone marks the base of the Katberg Formation on Bergendal, and that NMQR 3564 comes from the base of this *Corresponding author. formation.

715 716 JOURNAL OF VERTEBRATE PALEONTOLOGY, VOL. 30, NO. 3, 2010

FIGURE 1. Phonodus dutoitorum, gen. et sp. nov., NMQR 3564. Photographs of skull in (A) left lateral, (B) palatal, (C) oblique posterolateral, and (D) occipital views.

Downloaded By: [Botha-Brink, Jennifer] At: 06:14 20 May 2010 MATERIAL AND METHODS Diagnosis—Small procolophonid characterized by the fol- lowing autapomorphies: ventral temporal roughly straight with NMQR 3564 is preserved ventral up in the conglomerate contact between maxilla and quadratojugal; bifurcated maxil- (Fig. 1). As preparation progressed dorsally, up the lateral sur- lary process of premaxilla; relatively large posterior-most max- faces of the skull roof, we realized that not only was the braincase illary tooth; prefrontal-prefrontal dorsal midline contact; lat- missing, but the skull table (consisting of the frontals, the pari- eral temporal fenestra present; vomer with two large conical etals, the postfrontals [if present as distinct elements], the postor- teeth; pterygoid edentulous; transverse process of pterygoid rel- bitals, the supratemporals, and the postparietals) was lost prior atively small; and small accessory process present medially on to burial as well. In to ensure the integrity of the snout and quadrate. temporal regions, we decided not to remove the skull completely Holotype—NMQR 3564, a partial skull. from the block, but to leave it attached via the dorsolateral sur- Locality and Horizon—A locality on the farm Bergendal in face of the right side; only the left side together with the dorsal Noupoort District, Northern Cape Province, Republic of South surface of the snout of the skull roof is revealed for the following Africa. Katberg Formation, , . description. NMQR 3564 is positioned low stratigraphically in the Katberg Formation and, thus, low in the Lystrosaurus Assemblage Zone (Groenewald and Kitching, 1995). Lower Triassic; Induan Stage. SYSTEMATIC PALEONTOLOGY Detailed locality data are available from the Department of Ka- Olson, 1947 roo Palaeontology of the National Museum, Bloemfontein, to Lydekker in Nicholson and Lydekker, qualified researchers. 1889 Etymology—From phonos and odus, Greek for ‘murderous’ LEPTOPLEURONINAE Ivachnenko, 1979 and ‘tooth’ respectively, gender masculine. The specific epithet PHONODUS DUTOITORUM, gen. et sp. nov. honors Jan and Susan du Toit, owners of the farm Bergendal, for (Figs. 1, 2) their hospitality and interest in our work. MODESTO ET AL.—NEW TRIASSIC PROCOLOPHONID PARAREPTILE 717

DESCRIPTION that would be indicative of the insetting seen in and other procolophonids (Carroll and Lindsay, 1985:fig. 3; Sues The holotype and only known specimen of Phonodus dutoito- et al., 2000:fig. 2e). Posteromedially the maxilla contacts the pala- rum preserves little more than half of the skull roof. The pre- tine and the ectopterygoid, and forms the medial margin of the maxillae have been eroded away almost entirely, and the alveolar choana. Posteriorly the maxilla reaches the subtemporal fenestra portions of both maxillae are heavily weathered. The palate, in- and separates the jugal from the ectopterygoid in palatal aspect. cluding both quadrates, is preserved in articulation with the skull What is preserved of the maxillary dentition on both sides is roof, but the transverse flanges and condyles of both quadrates a single, relatively enormous tooth crown base that is positioned are weathered to varying degrees. The braincase, the mandible, just anterior to the level of the antorbital margin (Fig. 2B). In and the skull table are not preserved. palatal aspect the crown bases on both sides are irregularly oval in The skull is 25 mm long, a length that falls in the range of ju- outline. The mesiodistal diameter of both teeth is slightly greater venile of Procolophon trigoniceps (Carroll and Lindsay, than a third of the antorbital length of the skull. Damage to both 1985) and fenneri (Sues et al., 2000). The deeply teeth allows us to determine that the thickness of the tooth wall serrate dorsal midline suture formed by the nasals suggests, how- (sensu Modesto and Reisz, 2008) measures approximately 0.2–0.3 ever, that the skull is that of an adult individual. We use this crite- mm. The left tooth base is more complete than the right, and what rion of ontogenetic age from the cranial description of H. fenneri remains of its profile in both lateral and occipital aspects suggests by Sues and colleagues, which documents a straight internasal that it was a bulbous molariform tooth similar to the large maxil- contact in a juvenile specimen (Sues et al., 2000:fig. 3a) and an lary tooth of the procolophonid Haligonia bolodon interfingering suture in an adult (Sues et al., 2000:fig. 2a). (Sues and Baird, 1998:fig. 2). No other maxillary teeth are pre- served, but a small, circular, ventrally facing pocket immediately Skull Roof anterior to the left tooth base is probably the weathered alveolus Little more than fragments remain of both premaxillae. The for a small tooth. largest fragments are the enlarged maxillary processes and the Both nasals are preserved but only the left is exposed enough tips of the palatal processes. The former has an extensive con- for description. In lateral view the nasal is a relatively long, gen- tact with the anterior end of the maxilla and consists of two tly curving sheet of bone that extends from the anterior-most tip dorsally extending processes. The anterior process makes con- of the snout posteriorly to the prefrontal. It forms nearly the en- tact with the ventral margin of the nasal, thereby excluding the tire dorsal margin of the external naris. The dorsal surface of the maxilla from the external naris. The posterior ramus overlies the bone is smooth apart from a prominent, anteriorly directed fora- lateral surface of the maxilla and forms the posterior boundary men. This opening is in the same relative position as a cluster of of the maxillary depression (sensu Carroll and Lindsay, 1985). similarly oriented foramina on the nasal of seca (Modesto The palatal processes extend slightly farther posteriorly than the et al., 2002:fig. 1b) and Contritosaurus simus (Ivachnenko, 1974), maxillary processes. Each appears to contact the anterior end of although the nasal in NMQR 3564 does not appear to contribute the vomer via a scarf joint. The dorsal processes of the premax- to the maxillary depression as it does in those taxa. The oblique illae are preserved as tiny fragments in contact with the anterior view shows that the nasals formed a deeply serrate sagittal suture tips of the nasals. In ventral view the cross-section of each dorsal and that the nasal was bounded posteriorly by the prefrontal (i.e., process is seen to be transversely compressed (i.e., narrow), as no contact with the frontal). in procolophonoids and their close relatives (deBraga and Reisz, The prefrontals contact each other dorsally and form a short, 1996). deeply serrate suture along the midline (Fig. 2C). Heretofore a Septomaxillae are usually prominent elements positioned pos- prefrontal midline contact among parareptiles was known only teriorly in or along the posterior margin of the external naris, in owenettids (Reisz and Scott, 2002; Cisneros et al., 2004). The but no such structures are present. A pair of thin, weakly curved prefrontal forms the anterodorsal corner of the orbit and the dor- bones, exposed in section in palatal aspect immediately postero- sal half of a relatively broad antorbital buttress. It contacts the medial to the external nares, may be all that remains of the sep- nasal via a weakly sigmoidal suture, and shares deeply interfin- tomaxillae. gering contacts with the lacrimal and the palatine. Dorsally the Downloaded By: [Botha-Brink, Jennifer] At: 06:14 20 May 2010 The maxilla is a relatively deep, semilunar bone. Its lateral sur- posteromedial margin of the left prefrontal is well preserved and face is characterized by an extensive anterior fossa, the maxillary indicates that it shared a serrate suture with the frontal as well. A depression, and two conspicuous foramina. The maxillary depres- prefrontal ‘spur’ is not present. sion is a relatively shallow excavation with a distinct, nearly verti- The lacrimal is closely comparable to that of Procolophon cally aligned posterior margin and a bowed anterior margin that (Carroll and Lindsay, 1985). It has a roughly triangular facial por- extends to the suture with the nasal and the anterior ramus of tion that contacts the nasal anteriorly, the prefrontal dorsally, and the maxillary process of the premaxilla. Just posterior to the pos- the maxilla and the jugal ventrally, and a tongue-like orbital ex- terior ramus of the maxillary process of that element and dor- tension that overlies the lateral edge of the palatine and contacts sal to the ventral margin of the maxilla lies the anterior lateral the ectopterygoid. Together the lacrimal and the palatine, and maxillary foramen (sensu Laurin and Reisz, 1995). It is approx- perhaps a superficial contribution from the ectopterygoid as well, imately twice the size of the posterior foramen and it opens an- form the dorsal opening of the suborbital foramen, as in other terolaterally, as this opening does in other parareptiles (Modesto, procolophonids (Carroll and Lindsay, 1985:fig. 9b; Modesto et al., 1999). The smaller opening appears to be a supralabial foramen, 2001:fig. 1a). Two lacrimal foramina, the dorsal one slightly larger in the position that one or two such openings are usually seen than the ventral, perforate the bone along the antorbital margin in procolophonoids (Modesto et al., 2002:fig.1a; Reisz and Scott, (Fig. 2C). 2002:fig. 2d). The slightly serrate suture with the nasal is relatively Phonodus dutoitorum is an unusual procolophonid in the sense long compared to those with the lacrimal and the jugal. Although that it exhibits neither a ventral temporal emargination nor a the maxilla and the quadratojugal are separated on both sides in quadratojugal cheek spine. The jugal does not have an exposed palatal aspect, this appears to be the result of lithostatic compres- ventral margin because the maxilla and the quadratojugal make sion and we infer that these two elements made a touch contact contact and form a distinctly sigmoidal ventral margin for the and excluded the jugal from the ventral margin. In lateral aspect skull roof. The jugal forms an extensive and deeply serrate su- the ventral margin of the maxilla is slightly concave, but anteri- ture with the quadratojugal, and a prominent foramen issues orly the alveolar margins of both elements are heavily weathered. anteriorly approximately midway along this contact. Anteriorly There is no ventral beveling of the lateral surface of the bone the jugal contacts the lacrimal and the ectopterygoid, and has a 718 JOURNAL OF VERTEBRATE PALEONTOLOGY, VOL. 30, NO. 3, 2010

FIGURE 2. Phonodus dutoitorum, gen. et sp. nov., NMQR 3564. Interpretive drawings of skull in (A) left lateral, (B) palatal, (C) oblique postero- lateral, and (D) occipital views. Abbreviations: ar fl, arcuate flange; br, basicranial recess; de, maxillary depression; ec, ectopterygoid; f,vomerine fang; j, jugal; l,lacrimal;ltf, lateral temporal fenestra; m, maxilla; mf, anterior lateral maxillary foramen; n, nasal; pal, palatine; prf, prefrontal; prm,

Downloaded By: [Botha-Brink, Jennifer] At: 06:14 20 May 2010 premaxilla; pt, pterygoid, q, quadrate; qfl, quadrate flange of the pterygoid; qj, quadratojugal; sm, septomaxilla; sq, squamosal; t, maxillary tooth; tr fl; transverse flange of the pterygoid; v,vomer.

moderately long overlapping suture with the maxilla. Anterodor- most conspicuous features of the quadratojugal, that it shares an sally the jugal forms the gently concave ventral margin of the extensive interfingering contact with the jugal and excludes that orbit, and posterodorsally it projects an acuminate process that bone from the ventral margin in making a touch contact with the bears an elongate contact surface for the postorbital. Interest- maxilla, were noted above. ingly, the posterior edge of the posterodorsal end of the ju- Both squamosals are present and are typically procolophonid gal forms a free, moderately concave margin, which has its in construction. The facial portion of the bone, however, is greatly counterpart in a shallow, anteriorly facing emargination in the reduced to a slender, gently curving strip bordering the posterior squamosal. Thus, a small lateral temporal fenestra was present. temporal emargination. The anterodorsal edge of the bone forms The dorsal margin of this opening was presumably formed by the posterior margin of the small, elongate lateral temporal fen- the postorbital and, as suggested by the extensive contact surface estra ventrally and a narrowly quadrangular contact surface for that runs along the entire dorsal edge of the squamosal, possibly the supratemporal. The squamosal forms the approximate dor- by the supratemporal as well, in analogous fashion to the lateral sal half of the deep posteromedially aligned flange within the temporal fenestra restored for the owenettid barbouri posterior temporal emargination. This portion extends ventrally (Cisneros et al., 2004). to terminate just dorsal to the condylar region of the quadrate. The quadratojugal forms the ventral margin of the temporal The posterior margin of this region of the squamosal is thick- region and the ventral half of the posterior temporal emargina- ened and has the appearance of a pilaster in occipital view. The tion. The latter is defined ventrally by a dorsoventrally deep pos- squamosal has a deep overlapping contact with the dorsal lamella teroventral extension of the facial portion of the quadratojugal. of the quadrate, and a less extensive overlapping contact with the The facial portion of the bone is smooth and featureless. The quadrate process of the pterygoid. MODESTO ET AL.—NEW TRIASSIC PROCOLOPHONID PARAREPTILE 719

Palate ing surfaces of the quadrate condyles, indicating that when com- plete the transverse flange must have extended ventral to both The vomer is a narrow bone that bridges the premaxilla to the the quadrate and the ventral margin of the skull roof, as in H. rest of the palate (Fig. 2B). The ventral surface of each vomer fenneri and L. lacertinum. A thickened ridge runs posteriorly is dominated by two sharp, conical fangs. The double paired from the posterior corner of the transverse flange to the me- vomerine fang complex is positioned directly between the large dial edge of the arcuate flange formed by the ventral portion pair of maxillary teeth. The interchoanal portion is slightly thick- of the quadrate flange of the pterygoid, as it does in Pr. trigo- ened and is the broadest region of the bone, whereas the pos- niceps. The quadrate flange extends posterolaterally from the terior, post-dental third is conspicuously narrower and largely palatal portion of the bone. It is relatively abbreviated compared confluent with the ventral surface of the neighboring palatine to those of other procolophonids, comprising no more than about and pterygoid. Although the bones are slightly separated ante- 40% of the maximum length of the pterygoid, whereas this fig- riorly, what is visible of the sagittal contact (anterior and poste- ure is approximately 50% in Pr. trigoniceps (Carroll and Lind- rior to matrix that has been left to shore up the vomerine fangs) say, 1985:fig. 1b). The occipital view shows the quadrate flange of suggests that the intervomerine suture runs straight down the NMQR 3564 to be as deep as that in Pr. trigoniceps (Carroll and ventral midline. In ventral aspect, the free lateral margin of the Lindsay, 1985:fig. 1e, f). The dorsolateral corner of the quadrate bone forming the medial edge of the choana is slightly convex flange has an overlapping contact with the deep portion of the on the right side and weakly sigmoidal on the right. Posteriorly, squamosal. the vomer extends slightly more than half way (from the level The quadrate differs little from those of other procolophonids. of the posterior end of the choana) to the interpterygoid open- It consists of a condylar portion that abuts the medial surface of ing and makes contact with the pterygoid via a deeply serrate the quadratojugal and a dorsal lamella that appears to be sand- suture. wiched between the squamosal and the pterygoid. The condy- The most striking feature of the palatine is the absence of teeth, lar portion appears to be the same approximate anteroposte- an apomorphy that is shared only with the Late Triassic procolo- rior thickness as that seen in Pr. trigoniceps. The articulating phonids Hypsognathus fenneri (Sues et al., 2000) and Leptopleu- facets of both elements are weathered and their former bound- ron lacertinum (Sail¨ a,¨ 2008a). The palatine forms the shallowly aries cannot be delineated, but the facets appear to have been concave posterior margin of the choana. It contacts the vomer at least twice as broad as they were anteroposteriorly long and medially, forms a conspicuously serrate suture with the pterygoid vaguely dumbbell-shaped in outline. The dorsal lamella, nar- posteriorly, a weakly interfingering suture with the ectopterygoid rowly exposed in occipital view between the squamosal and laterally, and abuts the maxilla anterolaterally. The suborbital the pterygoid, is relatively tall; it is approximately one-half the foramen opens dorsally between the palatine and the lacrimal, preserved height of the skull. A remarkable feature of the but there is no evidence of a ventral egress for this foramen. In quadrate is a small, posterodorsally directed and medially curv- dorsal aspect the palatine forms the ventral half of a relatively ing process that extends from the posteromedial corner of the broad antorbital buttress, the lateral margin of which forms the bone, where the condylar portion meets the dorsal lamella (Fig. medial margin of the orbitonasal foramen. 2D). No other procolophonid exhibits a small process of this In ventral aspect the ectopterygid is a slender, narrowly kind. waisted element. Its slightly expanded anterior end contacts the maxilla and the jugal, whereas medially and posteromedially the ectopterygoid is bounded by the palatine and the pterygoid, re- DISCUSSION spectively. The bone forms a distinctly thickened anteromedial Relationships of Phonodus dutoitorum margin for the subtemporal fenestra. As in other procolophonids, the transversely thickened posterior end of the ectopterygoid Despite the absence of procolophonid hallmarks such as the contributes to the structure of the transverse flange. The apices of presence of a ventral temporal margin or quadratojugal spines, both flanges have been planed down by weathering, and thus the NMQR 3564 exhibits apomorphies that are indicative of a phy- full extent of the relative contributions of the ectopterygoid and logenetic placement within Procolophonidae. These include the

Downloaded By: [Botha-Brink, Jennifer] At: 06:14 20 May 2010 the pterygoid to the flange is unknown, but the resultant sections presence of a maxillary depression, the presence of a large maxil- reveal that the former element forms a slightly serrate internal lary tooth, and contact between the lacrimal and the ectoptery- contact with the latter. goid. In addition, the edentulous palatines are suggestive of a The structure of the pterygoid (Fig. 2B, C) differs in many re- close relationship with Leptopleuron lacertinum and Hypsog- spects from that seen in other procolophonids such nathus fenneri. as Procolophon trigoniceps, and resembles more the pterygoid of In order to test the hypothesis that Phonodus dutoitorum is Late Triassic forms. Most notably, it is devoid of teeth, like the a leptopleuronine procolophonid, we added this taxon to the pterygoid of H. fenneri (Sues et al., 2000). Anteriorly the ptery- data matrix of Cisneros (2008b) and reran the augmented matrix ∗ goids contact each other along the midline via a suture that pro- in PAUP 4.0b10 (Swofford, 2002). We added Kitchingnathus gresses from weakly meandering anteriorly to deeply serrate pos- untabeni to the matrix of Cisneros (2008b) using the line of teriorly. The interpterygoid vacuity is triangular in ventral aspect coding provided by Cisneros (2008c), but changed the codings and appears relatively long. Unlike the long, triangular opening for characters 1 and 40 to ‘0’ and ‘2,’ respectively. We also in the basal procolophonid Sauropareion anoplus (Modesto and changed the codings for characters 0, 1, 10, 24, and 37 to ‘0,’ ‘0,’ Damiani, 2007), the interpterygoid vacuity of NMQR 3564 ex- ‘0,’ ‘?,’ and ‘?,’ respectively, for Coletta seca (based on Modesto tends anteriorly only as far as the level of the posterior ends et al., 2002); the codings for characters 16 and 49 to ‘0 and ‘1,’ of the palatines, as in Pr. trigoniceps (Cisneros, 2008a:fig. 3a) respectively, for Sauopareion anoplus (based on Modesto and and phylogenetically younger procolophonids. A basicranial re- Damiani, 2007); the coding for character 1 to ‘0’ for Tichvinskia cess of moderate size demarcates the posterior end of the me- vjatkensis (based on Ivachnenko, 1973); and the coding for dial margin forming the interpterygoid vacuity. The transverse character 37 to ‘0’ for Leptopleuron lacertinum (based on Sail¨ a,¨ flange is reduced in lateral extent compared to that of Pr. trigo- 2008a). Whereas Cisneros (2008b) ordered six of his characters, niceps (Carroll and Lindsay, 1985), but not to the extent seen in we ran all characters unordered to minimize assumptions of H. fenneri (Sues et al., 2000) and L. lacertinum (Sail¨ a,¨ 2008a). character evolution. A branch-and-bound search discovered 90 The occipital view reveals that the preserved portions of both optimal trees (each 121 steps in length), the strict consensus transverse flanges extend ventrally to the level of the articulat- of which is shown in Figure 3. Apart from the inclusion of P. 720 JOURNAL OF VERTEBRATE PALEONTOLOGY, VOL. 30, NO. 3, 2010

FIGURE 3. Strict consensus of 90 opti- mal trees discovered in a PAUP∗ 4.0b10 analysis of a modified version of the data matrix from Cisneros (2008b). Tree length = 121, consistency index (CI) = 0.67, CI excluding uninformative characters = 0.66, rescaled CI = 0.53. We have condensed nine of the terminal taxa into more inclusive taxa for this figure, as follows: Theledectinae (‘Eumetabolodon’ dongshengensis, Theledectes perforatus), Procolophoninae (Eumetabolodon bathycephalus, Kapes spp., Procolophon trigo- niceps, Teratophon spinigenis, Thelephon con- tritus, Thelerpeton oppressus, Timanophon raridentatus). Phonodus dutoitorum is coded for the 58 characters of Cisneros (2008b) as follows: 1?A1111??? ?0001???1? ????????10 ?B0?1121?? ?????????? ???????? where ‘A’ and ‘B’ indicate uncertainty for states 1 and 2 and for states 3 and 4, respectively.

dutoitorum, the topology of the consensus tree is the same as Paleobiology of Phonodus dutoitorum that presented by Cisneros (2008c:fig. 5), with the exception that Dietary modes in procolophonoid reptiles have been inferred Kitchingnathus untabeni forms a polytomy with Coletta seca, primarily on the basis of the marginal dentition. Owenettids Pintosaurus magnidentis,andSauropareion anoplus at the base and basal procolophonids (e.g., Kitchingnathus untabeni)are of Procolophonidae (whereas only C. seca, P. magnidentis,and regarded as insectivores because most exhibit numerous, sim- S. anoplus formed a polytomy with a clade containing all other ple, non-occluding teeth, whereas larger and phylogenetically procolophonids in Cisneros, 2008b, and C. seca and S. anoplus younger procolophonids, including Procolophon trigoniceps and formed a clade at the base of Procolophonidae in Cisneros, Hypsognathus fenneri, are thought to be high-fiber be- 2008c [P. magnidentis was excluded in the analysis of Cisneros, cause they possess a reduced marginal dentition that features rel- 2008c]). atively large, occluding molariform teeth (Gow, 1978; Reisz and In all of our optimal trees Phonodus dutoitorum is a leptopleu- Sues, 2000; Cisneros, 2008c). Sues et al. (2000) cautioned, how- ronine. In a third of the optimal trees P. dutoitorum is the sister ever, that the consumption of arthropods with hard exoskeletons taxon of the least inclusive clade that includes Sclerosaurus ar- in addition to plant matter could not be ruled out for Pr. trigoni- matus and Hypsognathus fenneri; in another third it is the sister ceps, H. fenneri, and closely related forms. species of Neoprocolophon asiaticus; and in the remaining third it The severe weathering sustained by the marginal dentition of is the sister taxon of the least inclusive clade that includes N. asi- NMQR 3564 greatly complicates an assessment of the diet of aticus and H. fenneri. The decay analysis reveals that most Downloaded By: [Botha-Brink, Jennifer] At: 06:14 20 May 2010 Phonodus dutoitorum. Only the relatively enormous posterior within Procolophonidae collapse with the addition of a single maxillary teeth remain of the marginal dentition. Although some step, and there is no resolution among procolophonids following procolophonid taxa possess relatively large posterior maxillary two extra steps. teeth (e.g., Anomoiodon liliensterni:Sail¨ a,¨ 2008b; Thelerpeton op- Phonodus dutoitorum is the oldest known leptopleuronine. pressus: Modesto and Damiani, 2003), only Haligonia bolodon, The Induan age of this species mandates downward range exten- from the of Nova Scotia (Sues and Baird, 1998), has a pos- sions for two or three leptopleuronine lineages, depending on the terior maxillary tooth of such relative enormity. The remains of a exact phylogenetic position of P. dutoitorum. The topology with comparably small alveolus immediately anterior to the left max- the least stratigraphic debt positions P. dutoitorum as the sister illary tooth in NMQR 3564 suggests that the maxilla supported taxon of a leptopleuronine clade that contains N. asiaticus,and at least one much smaller tooth anterior to the large bulbous requires a long ghost lineage for Pentaedrusaurus ordosianus,a tooth, akin to the condition seen in Ha. bolodon (Sues and Baird, short ghost lineage for N. asiaticus, and a ghost taxon for the 1998:fig. 2). The large maxillary tooth of Ha. bolodon displays a ancestor of the clade containing the latter species and the re- small lingual wear facet on its apex. Sues and Baird (1998:527) maining leptopleuronines (Fig. 4A). The other two tree topolo- remark that this wear facet is poorly defined, and inferred that gies (Fig. 4B, C) exhibit slightly greater stratigraphic debt, and occlusion between upper and lower dentitions in Ha. bolodon require ghost lineages for both Pe. ordosianus and N. asiaticus was not developed to the degree seen in Pr. trigoniceps and H. and a ghost taxon for clade ‘N.’ These inferred range extensions fenneri. Possibly the occlusal condition seen in Ha. bolodon also indicate that a modest leptopleuronine diversity should be rep- pertained to P. dutoitorum, but the utter absence of crown apices resented in continental vertebrate faunas of Olenekian age, but in the latter precludes any inference into occlusion in that species. this is not evident in assembages of the late Early Triassic. Despite the lack of information on the crown morphology of In strong contrast, abundant fossils of representatives of the lep- the large maxillary teeth, certain aspects of the general skull mor- topleuronine , Procolophoninae, are not uncommon phology suggest that P. dutoitorum was durophagous: the largest at localities of Olenekian age (Kitching, 1977; Li, 1983; Cisneros, maxillary teeth are positioned ventral to well-developed antor- 2008b). bital buttresses and, apart from the presence of a small lateral MODESTO ET AL.—NEW TRIASSIC PROCOLOPHONID PARAREPTILE 721

FIGURE 4. Stratigraphically calibrated trees illustrating the implications of the three pos- sible phylogenetic positions of Phonodus du- toitorum within Leptopleuroninae for lepto- pleuronine diversity during the Olenekian. A, topology with the least stratigraphic debt. B–C, topologies with greater debt. The black bars in- dicate known ranges, the gray bar indicates un- certainty in the placement of the stratigraphic range of Pentaedrusaurus (following Cisneros, 2008b), and open bars indicate ghost lineages and ghost taxa. Clade ‘N’ refers to the clade of leptopleuronines identified in Figure 3. Nu- merical dates from Mundil et al. (2004) and Lehrmann et al. (2006).

temporal fenestra, the temporal region is entirely roofed over in relative to overall tooth size. At first glance, this suggests that the bone and there is no ventral emargination. The deeply interdig- teeth of the former taxon were structurally weaker than those of itating suture between the jugal and the quadratojugal presum- the former. However, Evans and Sanson (1998) remark that teeth ably served to resist the tensile forces that would have manifested of the same shape but of different sizes require different forces to between the alveolar region and the jaw articulation when the penetrate food items. A direct comparison of tooth efficiency be- large maxillary teeth were engaged during feeding. Our tree tween P. dutoitorum and C. aguti is complicated by the damage topology indicates that the temporal morphology seen in P. du- to those of the former taxon and minor shape differences, but toitorum is clearly a secondary condition, one that is derived from a corollary of Evans and Sanson’s (1998) observation on tooth the ventrally emarginated temporal condition retained in such efficiency is that one needs to be mindful of the absolute size taxa as Neoprocolophon asiaticus and Procolophon trigoniceps. of the . It follows that it is possible that the smaller size The closure of the ventral temporal emargination in P. dutoito- of P. dutoitorum, with a skull length of 25 mm, could account rum is analogous to the closure of the lateral temporal fenestra in for the absence of expected modifications for strengthening the the genus Araeoscelis, which was inferred by Reisz et al. walls of its teeth, because this procolophonid was probably not

Downloaded By: [Botha-Brink, Jennifer] At: 06:14 20 May 2010 (1984) to be an adaptative response to a durophagous diet of able to generate the jaw adductor forces that individuals of C. invertebrates. In P. dutoitorum, however, the ventral margin ap- aguti, which attained skull lengths of 80 mm (Seltin, 1959), would pears to have been closed by extensions of both the jugal and the have by virtue of their larger size. Pursuant to Evans and San- quadratojugal, resulting in a deeply interfingering contact. Given son’s (1998) statement on the relationship between tooth scale the uncertain relationship of P. dutoitorum to phylogenetically and tooth efficiency, it is interesting that the largest teeth of the younger taxa such as Scoloparia glyphanodon and Leptopleu- acleistorhinid parareptile Colobomycter pholeter are character- ron lacertinum, it is unclear whether the condition seen in P. ized by folding of the relatively thin tooth walls (Modesto, 1999; dutoitorum is ancestral to the condition seen in those younger Modesto and Reisz, 2008). Modesto and Reisz (2008:677) sug- leptopleuronines, in which a ventral emargination is also absent gested that this folding may have served to strengthen the largest but the ventral margin of the temporal region is markedly convex. teeth in C. pholeter. In this respect, we note that the skull of C. The evidence marshaled above for the hypothesis of pholeter is estimated to have attained at least 50 mm in length durophagy in P. dutoitorum is seemingly at odds with the obser- (Vaughn, 1958), thereby reaching twice the size of the skull of P. vation that the walls of the large maxillary teeth appear relatively dutoitorum. The walls of the large maxillary teeth of the latter thin: the thickness of the tooth wall ranges 0.2–0.3 mm, forming parareptile may not have required either thickening or mechan- roughly 8–12% of crown basal diameter (measured transversely ical support in the form of tooth folding because of the tiny size across the right tooth). To our knowledge, no histological work of its skull. has been published on procolophonoid dentition, but the work Finally, clues to the diet of Phonodus dutoitorum may be of Ricqles` and Bolt (1983:fig. 15) on the Early Permian eureptile drawn from the palatal dentition. The palate of this species Captorhinus aguti (a durophagous captorhinid according to Hot- is nearly edentulous apart from the presence of two pairs of ton et al., 1997) documents that the crown walls of the labial-most vomerine fangs. In addition to their conspicuous size, what is re- tooth in the multiple-rowed portion of the maxilla are 0.23–0.27 markable about the vomerine teeth is that they extend ventrally mm thick and form 33–44% of the basal diameter of the crown. directly between the large, bulbous maxillary teeth. It is difficult Thus, the crown walls of P. dutoitorum are approximately the to dismiss this organization of the marginal and palatal teeth as same absolute thickness as those of C. aguti, but they are thin coincidental, but given the incomplete crown morphology of the 722 JOURNAL OF VERTEBRATE PALEONTOLOGY, VOL. 30, NO. 3, 2010

large maxillary teeth, it would be premature to draw conclusions recovery fauna from refugia in the Gondwanan hinterland. The on the purpose of this dental organization. The vomerine teeth latter hypothesis was proposed specifically to explain the origin do not exhibit distinct facets or other conspicuous wear, so of the archosauromorph reptiles of the South African Triassic it seems likely that they were used to pierce or to hold food (Reisz et al., 2000). Yates and Warren (2000) considered the pos- items. Pursuant to this observation, the apices of these fangs are sibility that stereospondyl temnospondyls may have weathered directed slightly posteriorly, which suggests that they served to the end-Permian extinctions in a Gondwanan refugium possibly keep food from moving (or slipping) anteriorly. We know of no located in what is now Africa, but favored a putative refugium in herbivorous tetrapods with remarkably few and relatively large because they thought central Gondwana might have palatal teeth with this orientation, so it seems plausible to us that been too dry to support a diverse temnospondyl fauna during the P. dutoitorum preyed on small invertebrates. We hope that future Permian. Such conditions were probably less of an impediment material will preserve more of the dentition than is present in for procolophonoids and other reptiles. the holotype and only known specimen, to test these inferences. CONCLUSIONS Origins of the Karoo Procolophonid Fauna We describe the anatomy of a new genus and species of lepto- Our description of Phonodus dutoitorum adds a new element pleuronine procolophonid from the Lower Triassic Katberg For- to the procolophonoid assemblage of the Induan part of the mation of South Africa. Phonodus dutoitorum, gen. et sp. nov., Lystrosaurus Assemblage Zone of South Africa. Previously we is an unusual leptopleuronine because it lacks quadratojugal pro- (Botha et al., 2007) reported a modest diversity of Induan pro- cesses and a ventral temporal emargination, but exhibits a lat- colophonoids that spanned the uppermost strata of the Balfour eral temporal fenestra. It is diagnosed also by the presence of a Formation and lowermost strata of the Katberg Formation, and single large maxillary tooth, midline dorsal contact between the formed part of a Permo-Triassic recovery fauna (sensu Smith prefrontals, reduced pterygoid flanges, and several other autapo- and Botha, 2005), and suggested that procolophonoids were not morphies. The damage to the marginal dentition and the nearly greatly perturbed by the mass extinction of 252 million years ago. edentulous palate together preclude a definitive statement on the This small assemblage of Induan-age Karoo procolophonoids probable diet of P. dutoitorum, but the presence of large marginal now comprises two owenettids (‘’ kitchingorum and teeth is suggestive of durophagy, and the presence and the mor- Saurodektes rogersorum), two basal procolophonids (Coletta seca phology of well-developed vomerine fangs suggest that this lep- and Sauropareion anoplus), and a basal leptopleuronine procolo- topleuronine preyed on invertebrates. A phylogenetic analysis phonid (Phonodus dutoitorum). It exceeds the taxonomic and positions P. dutoitorum basally in Leptopleuroninae. The pre- morphological diversity of procolophonoids from the Laurasian cise relationship between P. dutoitorum and the other leptopleu- Induan, represented by Contritosaurus convector, C. simus,and ronines cannot be determined with the available evidence, but Phaanthosaurus ignatjevi from the Russian Platform. These the new species does not appear to be the most basal leptopleu- Laurasian taxa were thought to be so similar that Spencer and ronine. Each one of the three possible phylogenetic positions for Benton (2000) regarded the former genus to be a junior synonym P. dutoitorum suggests that the early evolutionary history of Lep- of the latter. topleuroninae is poorly recorded in the Lower Triassic. The de- The owenettid and procolophonid members of the Karoo scription of P. dutoitorum increases the number of Karoo Ind- Induan fauna are probably endemic forms (Modesto et al., uan procolophonoids to five, and it supports the hypothesis that 2002). Optimization of Laurasian and Gondwanan distributions procolophonoid evolution was not greatly affected by the Permo- onto the tree seen in Figure 3 (Fig. 1S, Supplementary Data Triassic mass extinction. 1, www.vertpaleo.org/jvp/JVPcontents.html) indicates that it is most parsimonious to infer that a Laurasian distribution is an- ACKNOWLEDGMENTS cestral for Leptopleuroninae, and that P. dutoitorum is a lepto- pleuronine migrant to the Karoo Basin. Accordingly, the taxo- We thank Jan and Susan du Toit for permission to prospect nomic diversity of Karoo Induan procolophonoids is comprised on Bergendal, and reviewers J. Cisneros and L. Sail¨ a¨ for useful Downloaded By: [Botha-Brink, Jennifer] At: 06:14 20 May 2010 predominantly of endemic Gondwanan taxa (the owenettids, Co. commentary. S.P.M. thanks M.V.H. Wilson for going above and seca,andS. anoplus), and it is enriched slightly by a faunal ele- beyond as editor to make last minute corrections to this paper. ment of Laurasian aspect (P. dutoitorum). This project was funded by discovery grants (nos. 288126-04 and The taxonomic and morphological diversity of the Karoo Ind- 288126-07) from the Natural Sciences and Engineering Research uan procolophonoids described here supports the hypothesis that Council (NSERC) of Canada to S.P.M. and R.R.R., a New Op- procolophonoid reptiles were not greatly perturbed by the envi- portunities Fund award from the Canadian Foundation for Inno- ronmental degradation that must have characterized terrestrial vation to S.P.M., and a grant (GUN 2061695) from the National environments in the wake of the extinctions that mark the Permo- Research Foundation of South Africa to J.B.B. Triassic boundary (PTB). This agrees with the general conclu- sions of Botha and Smith (2006) that terrestrial vertebrate fau- LITERATURE CITED nas in the Karoo Basin recovered from the PTB extinctions rela- tively rapidly, within about 5 million years (time equivalent to the Benton, M. J., V. P. Tverdokhlebov, and M. V. Surkov. 2004. Ecosystem remodelling among vertebrates at the Permian-Triassic boundary in Lystrosaurus AZ). This idea is consonant with the conclusions of Russia. Nature 432:97–100. Fraiser and Bottjer (2007) and Chen et al. (2007), but it contrasts Botha, J., and R. M. H. Smith. 2006. Rapid vertebrate recovery in the starkly with the interpretation that continental tetrapod faunas Karoo Basin of South Africa following the end-Permian extinction. of the Russian Platform showed little sign of recovery in the 15 Journal of African Earth Sciences 45:502–514. million years following the PTB event (Benton et al., 2004), and Botha, J., S. P. Modesto, and R. M. H. Smith. 2007. Extended pro- that full global recovery for continental tetrapod faunas required colophonoid reptile survivorship after the end-Permian extinction. some 30 million years (Sahney and Benton, 2008). Thus, it seems South African Journal of Science 103:54–56. likely that either continental environments in the Karoo Basin Carroll, R. L., and W. Lindsay. 1985. Cranial anatomy of the prim- during the Induan fostered a relatively rapid recovery of terres- itive reptile Procolophon. Canadian Journal of Earth Sciences 22:1571–1587. trial faunas, possibly owing to the monsoonal climate that char- Chen, Z. Q., J. Tong, K. Kaiho, and H. Kawahata. 2007. Onset of bi- acterized central Gondwana (Smith and Botha, 2005), or the Ka- otic and environmental recovery from the end-Permian mass ex- roo Basin was more successful in recruiting members for its PTB tinction within 1–2 million years: a case study of Lower Triassic of MODESTO ET AL.—NEW TRIASSIC PROCOLOPHONID PARAREPTILE 723

the Meishan section, South China. Palaeogeography, Palaeoclima- Modesto, S., H.-D. Sues, and R. Damiani. 2001. A new Triassic pro- tology, Palaeoecology 252:176–187. colophonoid reptile and its implications for procolophonoid sur- Cisneros, J. C. 2008a. Taxonomic status of the reptile genus Procolophon vivorship during the Permo-Triassic extinction event. Proceedings from the Gondwanan Triassic. Palaeontologia Africana 43:7–17. of the Royal Society of London B 268:2047–2052. Cisneros, J. C. 2008b. Phylogenetic relationships of procolophonid Modesto, S. P., R. J. Damiani, A. M. Yates, and J. Neveling. 2003. A new parareptiles with remarks on their geological record. Journal of Sys- Triassic owenettid parareptile and the Mother of Mass Extinctions. tematic Palaeontology 6:345–366. Journal of Vertebrate Paleontology 23:715–719. Cisneros, J. C. 2008c. New basal procolophonid reptile from the Kat- Mundil, R., K. R. Ludwig, I. Metcalf, and P. R. Renne. 2004. Age and tim- berg Formation (Lower Triassic) of the South African Karoo. Palae- ing of the Permian mass extinctions: U/Pb dating of closed-system oworld 17:126–134. zircons. Science 305:1760–1763. Cisneros, J. C., R. Damiani, C. Schultz, A.´ da Rosa, C. Schwanke, L. P. Nicholson, H. A., and R. Lydekker. 1889. A Manual of Palaeontology for Neto, and P. L. P. Aurelio.´ 2004. A procolophonoid reptile with tem- the Use of Students, third edition, Volume II. William Blackwood poral fenestration from the of Brazil. Proceedings of and Sons, Edinburgh and London, 735 pp. the Royal Society of London B 271:1541–1546. Olson, E. C. 1947. The family Diadectidae and its bearing on the classifi- Damiani, R., J. Neveling, S. Modesto, and A. Yates. 2004. Barendskraal, cation of reptiles. Fieldiana Geology 10:63–77. a diverse locality from the Lystrosaurus Assemblage Zone, Reisz, R. R., and D. Scott. 2002. Owenetta kitchingorum, sp. nov., a small Early Triassic of South Africa. Palaeontologia Africana 39:53–62. parareptile (: ) from the Lower Triassic [dated 2003] of South Africa. Journal of Vertebrate Paleontology 22:244–256. deBraga, M., and R. R. Reisz. 1996. The Early Permian reptile Acleis- Reisz, R. R., and H.-D. Sues. 2000. Herbivory in late Paleozoic and Trias- torhinus pteroticus and its phylogenetic position. Journal of Verte- sic terrestrial vertebrates; pp. 9–41 in H.-D. Sues (ed.), Evolution of brate Paleontology 16:384–395. Herbivory in Terrestrial Vertebrates: Perspectives from the Fossil Erwin, D. H. 1993. The Great Paleozoic Crisis: Life and Death in the Record. Cambridge University Press, Cambridge, U.K. Permian. Columbia University Press, New York, 327 pp. Reisz, R. R., D. S Berman, and D. Scott. 1984. The anatomy and rela- Evans, A. R., and G. D. Sanson. 1998. The effect of tooth shape on the tionships of the Lower Permian reptile Araeoscelis. Journal of Ver- breakdown of insects. Journal of Zoology, London 246:391–400. tebrate Paleontology 4:57–67. Fraiser, M. L., and D. J. Bottjer. 2007. Elevated atmospheric CO2 and Reisz, R. R., S. P. Modesto, and D. Scott. 2000. Acanthotoposaurus brem- the delayed biotic recovery from the end-Permian mass extinction. neri and the origin of the archosauromorph reptile fauna of South Palaeogeography, Palaeoclimatology, Palaeoecology 252:164–175. Africa. South African Journal of Science 96:443–445. Gow, C. E. 1978. The advent of herbivory in certain reptilian lineages Ricqles,` A. de, and Bolt, J. R. 1983. Jaw growth and tooth replacement in during the Triassic. Palaeontologia Africana 21:133–141. Captorhinus aguti (Reptilia: Captorhinomorpha): a morphological Groenewald, G. H., and J. W. Kitching. 1995. Biostratigraphy of the and histological analysis. Journal of Vertebrate Paleontology 3:7–24. Lystrosaurus Assemblage Zone; pp. 35–39 in B. S. Rubidge (ed.), Sahney, S., and M. J. Benton. 2008. Recovery from the most profound Biostratigraphy of the Beaufort Group (Karoo Supergroup). Coun- mass extinction of all time. Proceedings of the Royal Society B cil for Geosciences, Pretoria. 275:759–765. Hotton, N. C., III, E. C. Olson, and R. Beerbower. 1997. Amniote origins Sail¨ a,¨ L. K. 2008a. Leptopleuron, Anomoiodon and the Russian Permian and the discovery of herbivory; pp. 207–264 in S. S. Sumida and K. procolophonoids: a study of the interrelationships, evolution and L. M. Martin (eds.), Amniote Origins: Completing the Transition to palaeobiogeography of . Ph.D. dissertation, Uni- Land. Academic Press, San Diego. versity of Bristol, United Kingdom, 246 pp. Ivachnenko, M. F. 1973. Skull structure in the Early Triassic procolopho- Sail¨ a,¨ L. K. 2008b. The osteology and affinities of Anomoiodon nian Tichvinskia vjatkensis. Paleontological Journal 7:511–518. liliensterni, a procolophonid reptile from the Lower Triassic Ivachnenko, M. F. 1974. New data on the Early Triassic procolophonids Bundsandstein of Germany. Journal of Vertebrate Paleontology of the USSR. Paleontological Journal 8:346–351. 28:1199–1205. Ivachnenko, M. F. 1979. [Permian and Triassic procolophonians of Seltin, R. J. 1959. A review of the family Captorhinidae. Fieldiana Geol- the Russian Platform]. Trudy Paleontologicheskogo Instituta, ogy 10:461–509. Akademiia Nauka SSSR 164:1–80. [Russian] Sigogneau, D. 1963. Note sur une nouvelle espece` de Scaloposauridae. Kitching, J. W. 1977. The distribution of the Karroo vertebrate fauna. Palaeontologia Africana 8:13–37. Bernard Price Institute for Palaeontological Research, Memoir Smith, R., and J. Botha. 2005. The recovery of terrestrial vertebrate di- 1:1–131. versity in the South African Karoo Basin after the end-Permian ex- Laurin, M., and R. R. Reisz. 1995. A reevaluation of early amniote tinction. Comptes Rendus Palevol 4:555–568. Downloaded By: [Botha-Brink, Jennifer] At: 06:14 20 May 2010 phylogeny. Zoological Journal of the Linnean Society 113:165– Spencer, P. S., and M. J. Benton. 2000. Procolophonids from the Permo- 223. Triassic of Russia; pp. 160–176 in M. J. Benton, M. A. Shishkin, Lehrmann, D. J., J. Ramezani, S. A. Bowring, M. W. Martin, P. Mont- D. M. Unwin, and E. N. Kurochkin (eds.), The Age of Dinosaurs gomery, P. Enos, J. L. Payne, M. J. Orchard, H. M. Wang, and J. Y. in Russia and Mongolia. Cambridge University Press, Cambridge, Wei. 2006. Timing and recovery from the end-Permian extinction: U.K. geochronologic and biostratigraphic constraints from south China. Sues, H.-D., and D. Baird. 1998. Procolophonidae (Reptilia: Pararep- Geology 34:1053–1056. tilia) from the Upper Triassic Wolfville Formation of Nova Scotia, Li, J. L. 1983. Tooth replacement in a new genus of procolophonid from Canada. Journal of Vertebrate Paleontology 18:525–532. the Early Triassic of China. Palaeontology 26:567–583. Sues, H.-D., P. E. Olsen, D. M. Scott, and P. S. Spencer. 2000. Cranial Modesto, S. P. 1999. Colobomycter pholeter from the Lower Permian of osteology of Hypsognathus fenneri, a latest Triassic procolophonid Oklahoma: a parareptile, not a protorothyridid. Journal of Verte- reptile from the Newark Supergroup of eastern . brate Paleontology 19:466–472. Journal of Vertebrate Paleontology 20:275–284. Modesto, S. P., and R. J. Damiani. 2003. Taxonomic status of Theleg- Swofford, D. L. 2002. PAUP∗: Phylogenetic Analysis Using Parsimony nathus browni Broom, a procolophonid reptile from the South (∗and Other Methods). Version 4.0b10. Sinauer Associates, Sunder- African Triassic. Annals of the Carnegie Museum 72:53–64. land, Massachusetts. Modesto, S. P., and R. Damiani. 2007. The procolophonid reptile Sauro- Vaughn, P. P. 1958. On a new pelycosaur from the Lower Permian of pareion anoplus from the lowermost Triassic of South Africa. Jour- Oklahoma, and on the origin of the family Caseidae. Journal of Pa- nal of Vertebrate Paleontology 27:337–349. leontology 32:981–991. Modesto, S. P., and R. R. Reisz. 2008. New material of Colobomycter Yates, A. M., and A. A. Warren. 2000. The phylogeny of the ‘higher’ pholeter, a small parareptile from the Lower Permian of Oklahoma. temnospondyls (Vertebrata: Choanata) and its implications for the Journal of Vertebrate Paleontology 28:677–684. monophyly and origins of the Stereospondyli. Zoological Journal of Modesto, S., R. Damiani, and H.-D. Sues. 2002. A reappraisal of Co- the Linnean Society 128:77–121. letta seca, a basal procolophonoid reptile from the Lower Triassic of South Africa. Palaeontology 45:883–895. Submitted February 4, 2009; accepted August 24, 2009.