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 The Early Triassic Lystrosaurus Assemblage Zone (AZ) of the Karoo Basin is characterised by relatively low tetrapod diversity and the dominance of the dicynodont Lystrosaurus (Kitching, 1977). Collecting in the Lystrosaurus AZ (Fig. 1A) has traditionally been neglected due to the monotony of Lystrosaurus findings (Kitching, 1977), a genus that comprises up to 95% of the vertebrates in this horizon (Groenewald and Kitching, 1995). The procolophonoid Procolophon is also found in this biozone, occurring in isolated but usually large concen- trations (Groenewald and Kitching, 1995). Procolophonoids are the only clade of parareptiles that survived the Permo-Triassic extinction event and constitute part of the Early Triassic recovery fauna of the Karoo Basin (Fig. 1B; Modesto et al., 2001; Smith and Botha, 2005; Botha and Smith, 2006; Botha et al., 2007). The group radiated throughout Pangaea, and its last members are known from Upper Triassic rocks in Brazil, Britain, Canada * Present address: Departamento de Paleontologia e Estratigrafia, Universi- dade Federal do Rio Grande do Sul, Av. Bento Gonc ¸alves 9500, Porto Alegre, CP 15001, 91540-000, Brazil. Tel.: +55 51 3308 6385; fax: +55 51 3308 7302. E-mail address: cisneros.jc@gmail.com. and USA (Sues et al., 2000; Cisneros and Schultz, 2003; Fraser et al., 2005). In recent years, renewed attention has been given to the tetrapods of the Lystrosaurus AZ, resulting in the description of the new procolophonoids Owenetta kitchingorum (Reisz and Scott, 2002), Saurodektes rogersorum (Modesto et al., 2003), Coletta seca (Gow, 2000) and Sauropareion anoplus (Modesto et al., 2001), and probable new temnospondyl amphibians (Damiani et al., 2000; Damiani and Welman, 2001). Gow (1977) mentioned a procolophonid specimen from the Lystrosaurus AZ that somehow differed from the genus Procolophon in the den- tition. However, Gow (1977) concluded that this specimen was a juvenile Procolophon and the differences with other spec- imens were due to ontogeny. Gow (2000) changed his view and stated the possibility that the fossil could represent a new taxon. Based on this specimen, a new genus and species of basal procolophonid is described herein. 1.1. Institutional abbreviations AMNH, American Museum of Natural History, New York; BP, Bernard Price Institute for Palaeontological Research, Johannesburg; NM, National Museum, Bloemfontein; SAM, 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