A new species of basal rhynchosaur (Diapsida: Archosauromorpha) from the early Middle Triassic of South Africa, and the early evolution of Rhynchosauria. (23rd June 2015)

• Record Type: Journal Article
• Authors: Butler, Richard J.; Ezcurra, Martín D.; Montefeltro, Felipe C.; Samathi, Adun; Sobral, Gabriela
• Is Part Of: Zoological journal of the Linnean Society. Volume 174:Number 3(2015:Jul.)
• Page Start: 571
• Page End: 588
• Publication Date: 2015-06-23
• Subjects: Zoology -- Periodicals; 590
• DOI: 10.1111/zoj.12246
• Languages: English
• ISSNs: 0024-4082

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Rhynchosauria was an important clade of herbivorous archosauromorph reptiles during the Triassic, with a worldwide distribution. We describe a new genus and species of early rhynchosaur, <italic><bold>E</bold></italic><bold><italic>ohyosaurus wolvaardti</italic> gen. et sp. nov.</bold>, from the early Middle Triassic (early Anisian) <italic>Cynognathus</italic> Assemblage Zone (Subzone B) of the Karoo Supergroup, South Africa. <italic>Eohyosaurus wolvaardti</italic> is known from a single skull, and is recovered as the sister taxon of Rhynchosauridae in a new phylogenetic analysis. <italic>Cynognathus</italic> Subzone B has previously yielded the stratigraphically oldest well‐understood rhynchosaur species, <italic>Mesosuchus browni</italic> and <italic>Howesia browni</italic>. <italic>Eohyosaurus wolvaardti</italic> increases the rhynchosaur diversity within this stratigraphical horizon to three species. Intriguingly, all currently confirmed rhynchosaur occurrences from the Early Triassic to earliest Middle Triassic are from South Africa. This may suggest a relatively restricted palaeogeographical distribution for early rhynchosaurs, followed by a global dispersal of rhynchosaurids during the Middle Triassic. © 2015 The Linnean Society of London</p> </abstract>