Abstract
Sauropods, the giant long-necked dinosaurs, became the dominant group of large herbivores in terrestrial ecosystems after multiple related lineages became extinct towards the end of the Early Jurassic (190-174 Ma). The causes and precise timing of this key faunal change, as well as the origin of eusauropods (true sauropods), have remained ambiguous mainly due to the scarce dinosaurian fossil record of this time. The terrestrial sedimentary successions of the Cañadón Asfalto Basin in central Patagonia (Argentina) document this critical interval of dinosaur evolution. Here, we report a new dinosaur with a nearly complete skull that is the oldest eusauropod known to date and provide high-precision U-Pb geochronology that constrains in time the rise of eusauropods in Patagonia. We show that eusauropod dominance was established after a massive magmatic event impacting southern Gondwana (180-184 Ma) and coincided with severe perturbations to the climate and a drastic decrease in the floral diversity characterized by the rise of conifers with small scaly leaves. Floral and faunal records from other regions suggest these were global changes that impacted the terrestrial ecosystems during the Toarcian warming event and formed part of a second-order mass extinction event.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Proceedings of the Royal Society B: Biological Sciences
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
