Ben Creisler
A new paper:
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Highlights
Three distinct sauropodomorph faunas are recognized in the Triassic of South America.
A late Carnian fauna (Ischigualasto and Santa Maria formations) is characterized by small body sized animals (<50âkg) that were bipedal and that display diverse dental features compatible with animalivory and/or omnivory.
An early Norian fauna is recorded in the Caturrita Formation (Brazil) and shows the initial stages in the assemblage of the typical early sauropodomorph body plan, evidenced by the neck elongation and an initial development of herbivory.
The mid NorianâRhaetian sauropodomorph fauna is represented in Los Colorados and Quebrada del Barro formations and include a diverse assemblage of sauropodomorphs including the gracile Coloradisuchus, the robust riojasaurids, and lessemsaurids (the first giant sauropodomorphs).
Abstract
Sauropodomorpha is the first major dinosaurian group that radiated during the Triassic. During this time the group underwent major changes in body plan, including the acquisition of features related to herbivory, large body size, and quadrupedality. By the end of the Late Triassic, approximately 30 million years after the origin of dinosaurs, sauropodomorphs predominated the niches of large herbivores in continental ecosystems throughout the world. The Triassic sauropodomorph diversity includes diverse lineages with great disparity in body size, feeding biomechanics, and locomotion types, ranging from small (~10âkg) bipedal taxa to the large (>5 tons) quadrupedal lessemsaurids. The South American record has provided key information to understand certain stages of this evolutionary radiation. We review here the diversity and composition of sauropodomorph faunas throughout the Late Triassic of South America and highlight their contribution for understanding the evolution of this group.
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