The complete anatomy and phylogenetic relationships of Antetonitrus ingenipes (Sauropodiformes, Dinosauria): implications for the origins of Sauropoda. (28th March 2014)

• Record Type: Journal Article
• Authors: McPhee, Blair W.; Yates, Adam M.; Choiniere, Jonah N.; Abdala, Fernando
• Is Part Of: Zoological journal of the Linnean Society. Volume 171:Number 1(2014:May)
• Page Start: 151
• Page End: 205
• Publication Date: 2014-03-28
• Subjects: Zoology -- Periodicals; 590
• DOI: 10.1111/zoj.12127
• Languages: English
• ISSNs: 0024-4082

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>We present a comprehensive description and phylogenetic analysis of the important transitional sauropodomorph <italic>Antetonitrus ingenipes</italic>. New information sheds light on the stepwise acquisition of sauropod‐like traits just prior to the Triassic/Jurassic boundary. Although the forelimb of <italic>Antetonitrus</italic> and other closely related sauropodomorph taxa retains the plesiomorphic morphology typical of a mobile grasping structure, the changes in the weight‐bearing dynamics of both the musculature and the architecture of the hindlimb document the progressive shift towards a sauropodan form of graviportal locomotion. Nonetheless, the presence of hypertrophied muscle attachment sites in the femur of <italic>Antetonitrus</italic> suggests the retention of an intermediary form of facultative bipedalism. The term Sauropodiformes is adopted here and given a novel definition intended to capture those transitional sauropodomorph taxa occupying a contiguous position on the pectinate line towards Sauropoda. A re‐examination of the biased distribution of Sauropodomorpha in the earliest Jurassic suggests the presence of genuine palaeo‐environmental processes that may have excluded the large‐bodied, graviportal taxa from participating in a number of Early Jurassic ecosystems. © 2014 The Linnean Society of London</p> </abstract>