Ostrich-like dinosaurs referred to as ornithomimosaurs grew to huge sizes in historical jap North America, in accordance with a examine revealed October 19, 2022 within the open-access journal PLOS ONE by Chinzorig Tsogtbaatar of the North Carolina Museum of Pure Sciences and colleagues.
In the course of the Late Cretaceous Interval, North America was cut up by a seaway into two landmasses: Laramidia to the west and Appalachia to the east. However fossils from Appalachia are uncommon, and due to this fact historical ecosystems from this area are poorly understood. On this examine, Chinzorig and colleagues describe new fossils of ornithomimosaur dinosaurs from the Late Cretaceous Eutaw Formation of Mississippi.
Ornithomimosaurs, the so-called “bird-mimic” dinosaurs, had been superficially ostrich-shaped with small heads, lengthy arms, and powerful legs. The brand new fossils, together with foot bones, are round 85 million years outdated, making them a uncommon glimpse right into a poorly identified interval of North American dinosaur evolution
By evaluating the proportions of those fossils and the patterns of development throughout the bones, the authors decided that the fossils probably signify two totally different species of ornithomimosaurs, one comparatively small and one very massive. They estimate the bigger species to have weighed over 800 kg, and the person examined was probably nonetheless rising when it died. This makes it among the many largest ornithomimosaurs identified.
These fossils present precious insights into the in any other case poorly understood dinosaur ecosystems of Late Cretaceous jap North America. In addition they make clear ornithomimosaur evolution; big physique sizes and a number of species residing side-by-side are recurring traits for these dinosaurs throughout North America and Asia. Additional examine will hopefully elucidate the explanations behind the success of those life methods.
The authors add: “The co-existence of medium- and large-bodied ornithomimosaur taxa throughout the Late Cretaceous Santonian of North America doesn’t solely present key data on the range and distribution of North American ornithomimosaurs from the Appalachian landmass, nevertheless it additionally suggests broader proof of a number of cohabiting species of ornithomimosaurian dinosaurs in Late Cretaceous ecosystems of Laurasia.”
Supplies offered by PLOS. Observe: Content material could also be edited for model and size.