Available online at www.sciencedirect.com Palaeoworld 17 (2008) 126–134 Research paper New basal procolophonid reptile from the Katberg formation (Lower Triassic) of the South African Karoo Juan Carlos Cisneros ∗ Bernard Price Institute for Palaeontological Research, University of the Witwatersrand, Private Bag 3 WITS 2050, Johannesburg, South Africa Received 19 December 2007; received in revised form 1 May 2008; accepted 19 June 2008 Available online 27 June 2008 Abstract A new procolophonid reptile, Kitchingnathus untabeni n. gen. et n. sp., is described from the uppermost strata of the Lystrosaurus Assemblage Zone of the Karoo Basin, South Africa. The new taxon co-occurs with the well-known Procolophon trigoniceps. The most distinctive feature of the new taxon is the presence of numerous small bicuspid molariforms in both the maxilla and the dentary. A phylogenetic analysis indicates that Kitchingnathus occupies a basal position among procolophonids. Character optimisation suggests that bicuspid teeth were acquired independently by the new taxon, and originated twice in procolophonid evolution. © 2008 Nanjing Institute of Geology and Palaeontology, CAS. Published by Elsevier Ltd. All rights reserved. Keywords: Parareptiles; Procolophonids; Lystrosaurus Assemblage Zone; Triassic; South Africa 1. Introduction and USA (Sues et al., 2000; Cisneros and Schultz, 2003; Fraser et al., 2005). The Early Triassic Lystrosaurus Assemblage Zone (AZ) of In recent years, renewed attention has been given to the the Karoo Basin is characterised by relatively low tetrapod tetrapods of the Lystrosaurus AZ, resulting in the description diversity and the dominance of the dicynodont Lystrosaurus of the new procolophonoids Owenetta kitchingorum (Reisz and (Kitching, 1977). Collecting in the Lystrosaurus AZ (Fig. 1A) Scott, 2002), Saurodektes rogersorum (Modesto et al., 2003), has traditionally been neglected due to the monotony of Coletta seca (Gow, 2000) and Sauropareion anoplus (Modesto Lystrosaurus findings (Kitching, 1977), a genus that comprises et al., 2001), and probable new temnospondyl amphibians up to 95% of the vertebrates in this horizon (Groenewald and (Damiani et al., 2000; Damiani and Welman, 2001). Gow (1977) Kitching, 1995). The procolophonoid Procolophon is also found mentioned a procolophonid specimen from the Lystrosaurus AZ in this biozone, occurring in isolated but usually large concen- that somehow differed from the genus Procolophon in the den- trations (Groenewald and Kitching, 1995). Procolophonoids are tition. However, Gow (1977) concluded that this specimen was the only clade of parareptiles that survived the Permo-Triassic a juvenile Procolophon and the differences with other spec- extinction event and constitute part of the Early Triassic recovery imens were due to ontogeny. Gow (2000) changed his view fauna of the Karoo Basin (Fig. 1B; Modesto et al., 2001; Smith and stated the possibility that the fossil could represent a new and Botha, 2005; Botha and Smith, 2006; Botha et al., 2007). taxon. Based on this specimen, a new genus and species of basal The group radiated throughout Pangaea, and its last members procolophonid is described herein. are known from Upper Triassic rocks in Brazil, Britain, Canada 1.1. Institutional abbreviations AMNH, American Museum of Natural History, New York; ∗ Present address: Departamento de Paleontologia e Estratigrafia, Universi- dade Federal do Rio Grande do Sul, Av. Bento Gonc¸alves 9500, Porto Alegre, BP, Bernard Price Institute for Palaeontological Research, CP 15001, 91540-000, Brazil. Tel.: +55 51 3308 6385; fax: +55 51 3308 7302. Johannesburg; NM, National Museum, Bloemfontein; SAM, E-mail address: [email protected]. Iziko, South African Museum, Cape Town. 1871-174X/$ – see front matter © 2008 Nanjing Institute of Geology and Palaeontology, CAS. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.palwor.2008.06.003 J.C. Cisneros / Palaeoworld 17 (2008) 126–134 127 Fig. 1. (A) Map of South Africa and Lesotho showing the location of the type locality (Hobbs Hill) of Kitchingnathus untabeni n. gen. et n. sp. The outcrops that yield Lystrosaurus Assemblage Zone fauna are represented in dark grey (after Groenewald and Kitching, 1995). (B) Stratigraphic chart showing the placement of South African procolophonoids (owenettids and procolophonids) in the geologic time. From left to right: periods, epochs, Karoo assemblage zones, Karoo formations, and taxa. Bars represent taxon ranges and solid circles indicate single specimen occurrences. The interval where the abundance of Procolophon trigoniceps is anomalously high (Neveling, 2004; Botha and Smith, 2006) is represented by a solid box. Owenettids are followed by an asterisk. Taxon ranges and occurrences after Neveling (2004), Botha and Smith (2006), Botha et al. (2007), Abdala et al. (2006) and Cisneros (2008b). Abbreviations: Chang., Changsingian; Ciste., Cistecephalus; Mid., Middleton Formation; P-Tr, Permian-Triassic Boundary; Wuchiaping., Wuchiapingian. 2. Systematic palaeontology niceps specimens collected during field trips led by James W. Kitching in 1952 and 1966. Kitching (1977) assigned the fossil- Parareptilia Olson, 1947 iferous horizons of this locality to the uppermost Lystrosaurus Procolophonoidea Romer, 1956 AZ sandstones. The matrix that holds BP/1/1187 is bright red Procolophonidae Cope, 1889 sandstone, characteristic of the middle-upper Katberg Formation and lowermost Burgersdorp Formation (Johann Neveling, pers. comm., 2006). Kitchingnathus untabeni was most likely col- Kitchingnathus n. gen. lected in the middle or upper horizons of the Katberg Formation Etymology : In honour of the late James W. Kitching, a prominent , a stratigraphic assessment that is consistent with the presence South African palaeontologist and collector of the specimen; and of the index genus Procolophon at the locality. The occurrence gnathus from the Greek , mandible. of Procolophon in South Africa is restricted to the interval Diagnosis : As for the type and only known species. between the middle part of the Katberg Formation and the lower- Type species Kitchingnathus untabeni : n. sp. most Burgersdorp Formation (Neveling, 2004; Smith and Botha, 2005; Botha and Smith, 2006). Kitchingnathus untabeni n. sp. Diagnosis: Autapomorphies of the new taxon include: (1) At (Figs. 2 and 3) least nine upper and eight lower, chisel-like, small bicuspid v. 1977 Procolophon trigoniceps Gow, p. 701, text-fig. 6. molariforms, with labial cusps taller and thinner than lingual Etymology: An isiZulu term meaning “from the hill”, a reference cusps; and (2) a long posterior process of the maxilla that extends to the locality where the fossil was collected. along the rim of the subtemporal emargination as much as the Types: Holotype, BP/1/1187. A partial skeleton, in the collection quadratojugal. of the Bernard Price Institute for Palaeontological Research, Remarks: The new taxon possesses the highest number of bicus- University of the Witwatersrand, Johannesburg. Collected by pid teeth reported for a procolophonid. In Phaanthosaurus James W. Kitching in October 1952. (Contritosaurus) from the Lower Triassic of Russia, a similar Locality and horizon: Hobbs Hill (Windvogelsberg), west of count of bicuspid teeth (up to eight) is recorded in the max- Cathcart, Eastern Cape Province, South Africa; middle-upper illa. However, this form can readily be distinguished from the Katberg Formation, Beaufort Group, Karoo Supergroup, upper- new taxon in having a deeper snout and short upper incisiforms most Lystrosaurus AZ (Kitching, 1977), late Early Triassic which do not surpass the height of the molariforms, and by the (Olenekian). Besides the holotype of Kitchingnathus untabeni, absence of lower bicuspid teeth. The new taxon differs from the locality Hobbs Hill has yielded several Procolophon trigo- Sauropareion anoplus also by having a broader subtemporal 128 J.C. Cisneros / Palaeoworld 17 (2008) 126–134 emargination and a posterior median parietal projection. It is part of the cranium and disarticulated mandibular elements of further distinguished from the co-occurring Procolophon trigo- BP/1/1187 from the largest part of the block. This fracture was niceps by a number of characters (see below), including a longer filled with non-reversible glue, probably in the field or during snout and the absence of quadratojugal horns. preparation for Gow’s (1977) study, making it difficult to search for additional remains of the left side of the cranium. Removal of 2.1. Description the glue could cause serious damage to the prepared and already informative parts of the specimen, and for this reason, no attempt 2.1.1. Cranium of further preparation was done below the exposed regions of The cranium of BP/1/1187 (Figs. 2 and 3A) is compressed the skull. Instead, some additional preparation was carried out laterally and fractured loosely along the midline, producing the on the exposed side of the specimen. separation of right and left sides before burial of the specimen. Kitchingnathus possesses a gracile skull. The snout is elon- Most of the left side of the cranium is probably missing. Some gated, and slightly deeper than in Coletta seca but comparable unidentified flat bones that lay below the posterior margin of to that of Tichvinskia vjatkensis from Russia (see Ivakhnenko, the right side of the cranium presumably belong to the left side. 1973). The external surface of the snout is not well preserved, A tooth bearing fragment may represent a portion of the left and it