The recent unearthing of a remarkable fossil site in Argentina is offering fresh insights into life towards the end of the Cretaceous period, just prior to the extinction of non-avian dinosaurs.
During the Geological Society of America’s GSA Connects 2023 meeting, Matthew Lamanna, a principal dinosaur researcher at the Carnegie Museum of Natural History, presented exciting fossil discoveries from the Cañadón Tomás Quarry, situated in the Patagonia region of southern Argentina.
Lamanna highlights the scarcity of knowledge regarding Cretaceous dinosaurs and other vertebrates in the Southern Hemisphere compared to the Northern Hemisphere. This imbalance in understanding biodiversity and evolution motivates the investigation into how non-avian dinosaurs in the southern hemisphere fared during the Cretaceous-Paleogene boundary.
The discovery of the Cañadón Tomás site in early 2020 during petroleum exploration led to the unearthing of dinosaur fossils during a paleontological impact study. Noelia Cardozo, a UNPSJB PhD student involved in the research team, recalls the gradual expansion of excavations after the initial recovery of dinosaur bones in 2020, leading to the subsequent discovery of hadrosaur fossils of varying sizes.
The site may have preserved a social group or herd of related hadrosaur individuals buried together, hinting at intriguing investigations ahead. Additionally, the team uncovered remains from two predatory dinosaurs, along with fascinating finds of rare small-bodied vertebrates.
Among these discoveries are a snake vertebra, likely a madtsoiid, marking the first Cretaceous snake found in the Golfo San Jorge Basin. Another significant find was the upper jaw containing teeth of a reigitheriid, a small mammal, a rarity within a site known mainly for its dinosaur record.
The remarkable discovery of the mammal jaw, the first Cretaceous mammal found in the Golfo San Jorge Basin, highlights the importance of comprehending mammalian life in the Cretaceous period. The excavation work at Cañadón Tomás promises further exciting discoveries as it continues.
UNPSJB Ph.D. student Bruno Alvarez notes the substantial diversity and quantity of materials being unearthed at the site, underscoring the need for extensive fieldwork to uncover and study more fossils.
Lamanna expresses eagerness about future discoveries from Cañadón Tomás, anticipating that the site could offer significant insights into Cretaceous-Paleogene faunal dynamics, extinction processes in the Southern Hemisphere, and potentially unveil new animal species. Overall, Cañadón Tomás stands as a site with enormous potential, sparking high excitement and anticipation among the researchers involved.
Header Image Credit : Kara Fikse