A research led by The College of Texas at Austin is offering a glimpse into dinosaur and chicken variety in Patagonia through the Late Cretaceous, simply earlier than the non-avian dinosaurs went extinct.
The fossils symbolize the primary file of theropods — a dinosaur group that features each fashionable birds and their closest non-avian dinosaur kinfolk — from the Chilean portion of Patagonia. The researchers’ finds embrace big megaraptors with giant sickle-like claws and birds from the group that additionally contains at this time’s fashionable species.
“The fauna of Patagonia main as much as the mass extinction was actually various,” mentioned lead writer Sarah Davis, who accomplished this work as a part of her doctoral research with Professor Julia Clarke on the UT Jackson Faculty of Geosciences Division of Geological Sciences. “You’ve obtained your giant theropod carnivores and smaller carnivores in addition to these chicken teams coexisting alongside different reptiles and small mammals.”
Since 2017, members of the Clarke lab, together with graduate and undergraduate college students, have joined scientific collaborators from Chile in Patagonia to gather fossils and construct a file of historic life from the area. Through the years, researchers have discovered plentiful plant and animal fossils from earlier than the asteroid strike that killed off the dinosaurs.
The research focuses particularly on theropods, with the fossils courting from 66 to 75 million years in the past.
Non-avian theropod dinosaurs had been largely carnivorous, and embrace the highest predators within the meals chain. This research reveals that in prehistoric Patagonia, these predators included dinosaurs from two teams — megaraptors and unenlagiines.
Reaching over 25 ft lengthy, megaraptors had been among the many bigger theropod dinosaurs in South America through the Late Cretaceous. The unenlagiines — a gaggle with members that ranged from chicken-sized to over 10 ft tall — had been in all probability coated with feathers, identical to their shut relative the velociraptor. The unenlagiinae fossils described within the research are the southernmost recognized occasion of this dinosaur group.
The chicken fossils had been additionally from two teams — enantiornithines and ornithurines. Though now extinct, enantiornithines had been probably the most various and plentiful birds tens of millions of years in the past. These resembled sparrows — however with beaks lined with enamel. The group ornithurae contains all fashionable birds dwelling at this time. Those dwelling in historic Patagonia could have resembled a goose or duck, although the fossils are too fragmentary to inform for certain.
The researchers recognized the theropods from small fossil fragments; the dinosaurs largely from enamel and toes, the birds from small bone items. Davis mentioned that the enamel glinting on the dinosaur enamel helped with recognizing them among the many rocky terrain.
Some researchers have urged that the Southern Hemisphere confronted much less excessive or extra gradual climatic adjustments than the Northern Hemisphere after the asteroid strike. This will have made Patagonia, and different locations within the Southern Hemisphere, a refuge for birds and mammals and different life that survived the extinction. Davis mentioned that this research can help in investigating this concept by increase a file of historic life earlier than and after the extinction occasion.
Examine co-author Marcelo Leppe, the director of the Antarctic Institute of Chile, mentioned that these previous information are key to understanding life because it exists at this time.
“We nonetheless must understand how life made its approach in that apocalyptic state of affairs and gave rise to our southern environments in South America, New Zealand and Australia,” he mentioned. “Right here theropods are nonetheless current — now not as dinosaurs as imposing as megaraptorids — however as the various array of birds discovered within the forests, swamps and marshes of Patagonia, and in Antarctica and Australia.”
The analysis was funded by the Nationwide Science Basis, the Nationwide Company for Analysis and Growth of Chile, and the Jackson Faculty of Geosciences.
The research’s co-authors embrace Clarke and researchers on the College of Chile, Main College, the College of Concepción and the Chilean Nationwide Museum of Pure Historical past.
Header Picture Credit score : Mauricio Alvarez and Gabriel Diaz