A new eutherocephalian (Therapsida, Therocephalia) from the upper Permian Madumabisa Mudstone Formation (Luangwa Basin) of Zambia

Abstract

<div><p>ABSTRACT</p><p>A new therocephalian therapsid, <i>Ichibengops munyamadziensis</i>, gen. et sp. nov., is described on the basis of two partial skulls from the upper Permian (Wuchiapingian) upper Madumabisa Mudstone Formation of the Luangwa Basin, Zambia. The specimens offer insights into the diversity of therocephalians in a poorly sampled region, preserving unique maxillary structures, dental morphology that is intermediate between basal therocephalians and eutherocephalians, and a maxillovomerine bridge forming an incipient secondary palate. A phylogenetic analysis of 135 craniodental and postcranial characters from 56 therapsid taxa (including 49 therocephalians) recovered <i>I. munyamadziensis</i> as the sister taxon of the Russian <i>Chthonosaurus</i>, with both taxa resolving near the hofmeyriid + whaitsiid + baurioid clade (either as the sister group to this clade or nested near whaitsiids). <i>Ichibengops</i> shares with <i>Chthonosaurus</i> several features, including a ventral maxillary flange in which the upper postcanines are situated (also in <i>Lycosuchus</i>), anteroposteriorly short suborbital vacuities with strongly scalloped anterior borders, a furrowed or ridged surface texture on the palatal surface of the palatine, and a possible maxillovomerine bridge (although this latter structure is incompletely preserved in <i>Chthonosaurus</i>). The new taxon, along with its proposed relationship to <i>Chthonosaurus</i>, adds to a list of sister-group pairs of Wuchiapingian tetrapods in southern Gondwana and Laurasia, indicating that effective, though largely unknown, dispersal routes persisted in Pangea at least through early late Permian times.</p><p>http://zoobank.org/urn:lsid:zoobank.org:pub:3C00620E-64B4-4CF0-BFAD-0336AE7C8196</p><p>SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP</p></div