This article was downloaded by: [University of Guelph] On: 30 April 2012, At: 12:37 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 Systematic Palaeontology Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/tjsp20 Systematics of the Anteosauria (Therapsida: Dinocephalia) Christian F. Kammerer a a Department of Vertebrate Paleontology, American Museum of Natural History, New York, 10024-5192, USA Available online: 13 Dec 2010 To cite this article: Christian F. Kammerer (2011): Systematics of the Anteosauria (Therapsida: Dinocephalia), Journal of Systematic Palaeontology, 9:2, 261-304 To link to this article: http://dx.doi.org/10.1080/14772019.2010.492645 PLEASE SCROLL DOWN FOR ARTICLE Full terms and conditions of use: http://www.tandfonline.com/page/terms-and-conditions This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, 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 Systematic Palaeontology, Vol. 9, Issue 2, June 2011, 261–304 Systematics of the Anteosauria (Therapsida: Dinocephalia) Christian F. Kammerer∗ Department of Vertebrate Paleontology, American Museum of Natural History, New York 10024-5192, USA (Received 17 December 2009; accepted 26 April 2010; printed 31 May 2011) Anteosaurs (Therapsida: Dinocephalia: Anteosauria) were the dominant terrestrial predators during the late Middle Permian period and are known from southern Africa, the former USSR, China and Brazil. This paper presents a critical taxonomic review of all known anteosaur taxa and a reevaluation of anteosaurian interrelationships. The following anteosaur species are considered to be valid: Anteosaurus magnificus, Archaeosyodon praeventor, Australosyodon nyaphuli, Microsyodon orlovi, Notosyodon gusevi, Sinophoneus yumenensis, Syodon biarmicum, Titanophoneus adamanteus and T. potens. Syodon efre- movi is considered a junior synonym of S. biarmicum, Stenocybus acidentatus to represent juvenile material of Sinophoneus yumenensis, Doliosauriscus yanshinovi a junior synonym of Titanophoneus potens,andParanteosaurus primus a junior synonym of Anteosaurus magnificus. Admetophoneus kargalensis, Archaeosuchus cairncrossi, Brithopus bashkyricus, B. ponderus, B. priscus, Eccasaurus priscus, Lamiasaurus newtoni and Orthopus primaevus are regarded as nomina dubia. ‘Titanophoneus’ rugosus is tentatively considered the first representative of the genus Anteosaurus in Russia. Phyloge- netic analysis of anteosaurs recovers a monophyletic Anteosauridae containing two major clades, Syodontinae (containing Australosyodon, Notosyodon and Syodon) and Anteosaurinae (containing Anteosaurus, Sinophoneus and Titanophoneus). The Russian taxa Archaeosyodon and Microsyodon represent the most basal anteosaurs. Anteosaurian skulls share many features in common with those of large-bodied predatory taxa such as tyrannosaurid dinosaurs, and anteosaurines in particular exhibit characters associated with handling large prey items and possibly bone-crushing. Keywords: Therapsida; Dinocephalia; Anteosauria; Anteosauridae; Permian Introduction Brithopus (a wastebasket taxon for Ural copper measures dinocephalian postcranial material) and better-known Anteosaurs are one of the two major groups of Russian taxa such as Syodon and Titanophoneus. Brithopo- dinocephalians, a diverse but short-lived therapsid clade didae was extensively used by subsequent workers (Romer that represented one of the most widespread and success- 1956, 1966; Watson & Romer 1956; Olson 1962; Boonstra ful amniote radiations in the Middle Permian. Anteosaurs 1963; Kemp 1982; Tchudinov 1983; Sues 1986; King 1988; were the largest terrestrial predators in the Middle Permian Battail & Surkov 2000) to refer to all non-Anteosaurus (∼270–260 Ma; Eodicynodon–Tapinocephalus Assem- anteosaurs (although not all of these authors considered blage Zones of South Africa, Zones I–II of Russia), with ‘anteosaurs’ to represent a natural group), and was later skulls exceeding 80 cm in length. They were also the emended to such nomenclaturally incorrect forms as Downloaded by [University of Guelph] at 12:37 30 April 2012 first non-mammalian therapsids to be discovered, although Brithopidae and Brithopia (Boonstra 1972; Kemp 1982; they were not initially recognized as such (Kutorga 1838). King 1988). Indeed, despite their distinctive cranial anatomy (Fig. Hopson & Barghusen (1986) argued that use of the 1), anteosaurs were not recognized as a separate group term ‘Brithopodidae’ should be discontinued and that the of dinocephalians until work by Boonstra (1954a), who Russian taxa Syodon, Titanophoneus and Doliosauriscus separated Anteosauridae from Titanosuchidae, a group should be placed with Anteosaurus in Anteosauridae. of herbivorous therapsids currently placed in the other They recognized three additional taxa: Anteosauria, a major dinocephalian group, Tapinocephalia (Hopson & monofamilial higher taxon for Anteosauridae to com- Barghusen 1986). plement Tapinocephalia; Anteosaurinae, containing Even following Boonstra’s (1954a) recognition that Titanophoneus, Doliosauriscus and Anteosaurus; and Anteosaurus belonged to a distinct radiation of carnivorous Anteosaurini, containing only the giant anteosaurs dinocephalians, the various taxa currently considered Doliosauriscus and Anteosaurus. King (1988) retained anteosaurs had a tenuous history of association. Efremov Brithopidae [sic] (containing the subfamilies Brithopinae (1954) named a new family, Brithopodidae, to refer to [sic] and Anteosaurinae) and placed both ‘Brithopidae’ ∗Email: [email protected] ISSN 1477-2019 print / 1478-0941 online Copyright C 2011 The Natural History Museum DOI: 10.1080/14772019.2010.492645 http://www.informaworld.com 262 C. F. Kammerer Titanosuchus and Jonkeria. Ivakhnenko (1994, p. 102) also argued that the taxon Brithopodidae is invalid, and that the ‘Titanophoneus-Deuterosaurus group’ probably belongs in Anteosauridae, in which case the proper name for this group would be Deuterosauridae Seeley, 1894. Ivakhnenko (1995, 2003) considered both families to be valid, and united Anteosauridae (including Anteosaurus and Titanophoneus) and Deuterosauridae (Deuterosaurus only) in the superfamily Deuterosauroidea, while placing Syodontidae in Titanosuchoidea. As indicated by the conflicting taxonomic schemes presented above, despite over 170 years of research, anteosaurian systematics remains in a state of great confu- sion. The purpose of this paper is to critically review anteosaur alpha taxonomy and to establish a phylogenetic framework for anteosaur classification. Each nominal taxon currently considered distinct is treated separately. Nomi- nal taxa previously synonymized with other anteosaurian species are dealt with in the section concerning the oldest valid name. Materials Type material of each nominal anteosaurian taxon was personally examined by the author, with the exception of LGU 140/1, the holotypic canine of Syodon biarmicum, and the type material of Titanognathus lotzi, which was apparently destroyed during WWII (King 1988). Institutional abbreviations Figure 1. The skull of a representative anteosaurid (Syodon AMG: Albany Museum, Grahamstown, South Africa; biarmicum)inA, right lateral; B, dorsal; and C, palatal views. AMNH: American Museum of Natural History, New Reconstruction based predominantly on PIN 157/2, the holotype of Cliorhizodon efremovi. Key anteosaurian characters visible in Yo r k C i t y, N e w Yo r k , U S A ; BMNH: Natural History A include the strongly recurved (‘hook-like’) canine, upward Museum, London, UK; BP: Bernard Price Institute, Univer- canted alveolar margin of the premaxilla, bulbous postcanines, sity of the Witwatersrand, Johannesburg, South Africa; and temporal fenestra undercutting the orbit. Note in B the contri- BSPG: Bayerische Staatssammlung fur¨ Palaontologie¨ und bution of the frontal to the anterior edge of the pineal boss and the Downloaded by [University of Guelph] at 12:37 30 April 2012 historische Geologie, Munich, Germany; CGP: Council anterolateral curvature of the edge of the pineal boss where tempo- ral musculature attached, characteristic of Syodon, Australosyodon for Geosciences, Pretoria, South Africa; FMNH:Field and Notosyodon. Key anteosaurian characters visible in C include Museum of Natural History, Chicago, Illinois, USA; the ‘scroll-like’ vomers and quadrate rami of the pterygoid bifur- GMV: Geological Museum of China, Beijing, China; cating the basisphenoid. IGCAGS: Institute of Geology, Chinese Academy of Geological Sciences, Beijing, China; IVPP: Institute for and Titanosuchidae (containing Titanosuchinae and Vertebrate Paleontology and Paleoanthropology, Beijing, Tapinocephalinae) in the superfamily Anteosauroidea. China; LGU: Saint Petersburg State