Paleontologists have explained three new things Enantiornithine Cretaceous Hell Creek Formation birds, two of which are new species abysauridae seed. These birds lived alongside dinosaurs 68 million years ago, and their powerful leg bones suggest they may have captured and carried off prey.
Restoration of abyssaurids (e.g. Avisaurus Darwini). Image credit: Clark others., doi: 10.1371/journal.pone.0310686.
The most diverse bird species of the Cretaceous period was a now extinct group called the enantiornithines, which were known throughout the world during this period.
However, enantiornithines and other Mesozoic birds are known primarily from Early Cretaceous deposits, with records from the Late Cretaceous being relatively sparse.
Therefore, there is a general lack of understanding of the evolutionary trends of birds towards the end of the Mesozoic Era.
The fossilized remains of three new enantiornithine birds have been discovered in the Hell Creek Formation of Montana and date to the late Cretaceous period.
Two species were named new species. Magnusabis ekarakaensis and Avisaurus Darwiniwhile the third is an unnamed species. Avisaurus.
All of these birds were larger than the Early Cretaceous enantiornithines; Avisaurus Darwini It is estimated to weigh more than 1 kg, making it about the size of a large hawk.
“These discoveries virtually double the number of bird species known from the Hell Creek Formation and are important for a better understanding of why only some birds survived the mass extinction event. It will be.” tyrannosaurus and the abysaurid described here,” said Dr. Jingmai O'Connor, associate curator of fossil reptiles at the Field Museum.
When the team analyzed the leg bones, they found Avisaurus Hawks and owls and their relatives exhibit hawk- and owl-like proportions and adaptations, and, like some modern raptors, have powerful legs that can grasp and carry proportionately large prey. Shows muscles and legs.
“Based on clues in the leg bones, we think these birds were able to capture and transport prey, similar to modern hawks and owls,” said Dr. Alex Clark. students at the Field Museum and the University of Chicago.
“They may not have been the first raptors to evolve, but their fossils are the oldest known examples of predatory birds.”
This new species expands the known diversity of Late Cretaceous birds, confirms trends toward larger body sizes, and sheds light on how enantiornithines evolved a diversity of ecological roles over time. It's highlighted.
“Abyssaurids, the latest Cretaceous enantiornithid birds, display hindlimb features with strong ankle flexion, which contributes to the ability to carry heavy prey and similar behavior to modern raptors. “This suggests that,” the paleontologists said.
their paper Published in today's diary PLoS ONE.
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AD Clark others. 2024. New enantiornithine diversity of the Hell Creek Formation and functional morphology of avian tarsometatarsals. PLoS ONE 19 (10): e0310686;doi: 10.1371/journal.pone.0310686
Source: www.sci.news
