Paleontologists Find World’s Oldest Known Megaraptorid, Australia’s First Carcharodontosaur Fossils – Sci.News

Paleontologists have unearthed five new theropod fossils from the Cretaceous period, including two carcharodontosaurian specimens, in Victoria, Australia.The landscape of Cretaceous Australia. Image credit: Jonathan Metzger / Museums Victoria.The two carcharodontosaurian specimens provide the first evidence for this dinosaur group in Australia.They came from the Strzelecki Group (121.4-118 million years old) and the Eumeralla Formation (113-108 million years old).“The discovery of 2-4 m long carcharodontosaurs in Australia is groundbreaking,” said Museums Victoria Research Institute and Monash University Ph.D. student Jake Kotevski.“It’s fascinating to see how Victoria’s predator hierarchy diverged from South America, where carcharodontosaurs reached Tyrannosaurus rex-like sizes up to 13 m, towering over megaraptorids.”“Here, the roles were reversed, highlighting the uniqueness of Australia’s Cretaceous ecosystem.”The paleontologists also unearthed two megaraptorid specimens in the Strzelecki Group.The finds demonstrate that this dinosaur group had achieved large body size (6-7 m long) at the time of its first appearance in the fossil record.Additionally, the specimens demonstrate that relatively large-bodied megaraptorids flourished at high latitudes.“Two of the fossils represent the oldest known megaraptorids globally, expanding our understanding of the group’s evolutionary history and suggesting Australia’s theropod fauna played a pivotal role in Gondwanan ecosystems,” Kotevski said.“The findings not only expand Australia’s theropod fossil record but offer compelling evidence of faunal interchange between Australia and South America through Antarctica during the Early Cretaceous,” said Dr. Thomas Rich, senior curator of vertebrate palaeontology at Museums Victoria Research Institute.“The findings also challenge previous assumptions about body-size hierarchies in Gondwanan predator ecosystems highlighting Victoria’s unique Cretaceous fauna.”“Our team continue to survey key fossil sites, including where the fossils of the large megaraptorid were discovered, prompting new avenues of investigation for the Dinosaur Dreaming project, which has led to many significant discoveries including more than 10,000 fossil bones and teeth since the project began,” Kotevski said.A paper describing this research was published in the Journal of Vertebrate Paleontology._____Jake Kotevski et al. Evolutionary and paleobiogeographic implications of new carcharodontosaurian, megaraptorid, and unenlagiine theropod remains from the upper Lower Cretaceous of Victoria, southeast Australia. Journal of Vertebrate Paleontology, published online February 19, 2025; doi: 10.1080/02724634.2024.2441903

Source: https://www.sci.news/paleontology/megaraptorid-carcharodontosaur-fossils-australia-13684.html