A new genus and species of giant colossosaurian titanosaur has been identified from fossils found in Patagonia, Argentina.
An artist’s reconstruction of Notocolossus gonzalesparejasi, a sister taxon of Chucarosaurus diripienda. Image credit: Nobu Tamura, http://spinops.blogspot.com.
The newly-identified species lived in what is now Argentina during the Late Cretaceous epoch, between 95 and 93 million years ago.
Named Chucarosaurus diripienda, it was a large sauropod with relatively slender fore and hindlimbs.
It belongs to Colossosauria, a group of titanosaurian sauropods from the Early Cretaceous through the Late Cretaceous of South America.
“Titanosaurs were the most diverse and abundant terrestrial herbivores in the Southern Hemisphere landmasses during the Late Cretaceous,” said Dr. Federico Agnolin, a paleontologist with the Museo Argentino de Ciencias Naturales ‘Bernardino Rivadavia’ – CONICET and the Fundación de Historia Natural ‘Félix de Azara’ at the Universidad Maimónides, and his colleagues.
“They were globally widespread, and more than 60 valid species are known from South America.”
“Titanosaurs are restricted to the Cretaceous and are the most common dinosaurs found in Upper Cretaceous layers of South America, particularly in Patagonia.”
“A special paleobiogeographic aspect is their high diversity during the latest Cretaceous that rivals that of the hadrosaurid and ceratopsid ornithischians of northern hemisphere ecosystems at the same time.”
“Some titanosaurs are regarded as the most massive terrestrial animals known with weights reaching 70 tons and a size of about 37 m long.”
“Colossosauria comprises most of the truly giant titanosaurs like Argentinosaurus, Notocolossus, Patagotitan and Puertasaurus,” they added.
The specimen of Chucarosaurus diripienda were discovered in the Late Cretaceous layers of the Huincul Formation in the Neuquén Basin, Rio Negro province, northeastern Patagonia.
“It includes appendicular and relatively slender elements, with a femoral total length of about 1.9 m long,” the paleontologists said.
“In spite of being a well-sampled region, up to the date, giant colossosaurs were unknown in Mesozoic deposits from Río Negro province.”
“Chucarosaurus diripienda shows a unique combination of characters indicating that appendicular bones such as the femur, ischium and tibia, show a remarkable morphological variety, greater than previously described, and are morphologically informative as source of phylogenetic data,” they said.
“A cladistic phylogenetic analysis placed Chucarosaurus diripienda well nested within the Colossosauria clade, as a sister taxon of Notocolossus plus (Lognkosauria).”
The discovery of Chucarosaurus diripienda is reported in a paper in the journal Cretaceous Research.
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F.L. Agnolin et al. A new gigant titanosaur (Dinosauria, Sauropoda) from the Upper Cretaceous of Northwestern Patagonia, Argentina. Cretaceous Research, published online February 2, 2023; doi: 10.1016/j.cretres.2023.105487
Source : Breaking Science News