This article was downloaded by: [Botha-Brink, Jennifer] On: 20 May 2010 Access details: Access Details: [subscription number 922426270] Publisher Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37- 41 Mortimer Street, London W1T 3JH, UK Journal of Vertebrate Paleontology Publication details, including instructions for authors and subscription information: http://www.informaworld.com/smpp/title~content=t917000010 A new and unusual procolophonid parareptile from the Lower Triassic Katberg Formation of South Africa 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 Karoo Palaeontology, National Museum, Bloemfontein, South Africa 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 PLEASE SCROLL DOWN FOR ARTICLE Full terms and conditions of use: http://www.informaworld.com/terms-and-conditions-of-access.pdf This article may be used for research, teaching and private study purposes. Any substantial or systematic reproduction, re-distribution, re-selling, loan or sub-licensing, systematic supply or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material. Journal of Vertebrate Paleontology 30(3):715–723, May 2010 © 2010 by the Society of Vertebrate Paleontology 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 skull 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 autapomorphies. A cladistic analysis identifies P. dutoitorum as a basal member of the procolophonid clade 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 species to be described from the Induan of the Karoo Basin, providing further support for the hypothesis that procolophonoid evolution was not greatly perturbed by the end-Permian extinction event. INTRODUCTION phonid reptile, and discuss its implications for procolophonid evolution. Parareptiles were the most taxonomically and ecologically di- Institutional Abbreviation—NM, National Museum, Bloem- verse reptiles 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 tetrapods. 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 Extinctions the first major sandstone exposed on the Northern Cape farm (sensu Erwin, 1993). Indeed, procolophonoid fossils 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 Lystrosaurus the genus 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 tetrapod 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 order 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