Paleontologists have described three unique enantiornithine birds from the Cretaceous Hell Creek Formation, two of which signify unique avisaurid species. These birds lived alongside dinosaurs 68 million years in the past and their highly effective toes bones counsel they’ll also have captured and carried off prey.
Reconstruction of an avisaurid (e.g., Avisaurus darwini). Image credit rating: Clark et al., doi: 10.1371/journal.pone.0310686.
Basically the most various birds all the draw via the Cretaceous length had been a now-extinct community known as enantiornithines, known from around the realm all the draw via this time.
On the opposite hand, enantiornithines and diversified Mesozoic birds are essentially known from Lower Cretaceous deposits, with a relatively wretched portray from the Unhurried Cretaceous.
Thus, there could be a conventional lack of consciousness of traits in fowl evolution toward the discontinue of the Mesozoic period.
The fossilized remains of the three unique enantiornithine birds had been stumbled on in the Hell Creek Formation of Montana, dating to the latest Cretaceous length.
Two are unique species named Magnusavis ekalakaensis and Avisaurus darwini, whereas the third is an unnamed species of Avisaurus.
These birds are all greater than Early Cretaceous enantiornithines, with Avisaurus darwini estimated to have weighed over 1 kg, roughly the size of a super hawk.
“These discoveries have successfully doubled the need of fowl species known from the Hell Creek Formation and will almost definitely be essential for helping us to greater ticket why simplest some birds survived the mass extinction that wiped out T. rex and the avisaurids described here,” talked about Dr. Jingmai O’Connor, companion curator of fossil reptiles at Field Museum.
The personnel’s prognosis of the leg bones of Avisaurus and its family published proportions and diversifications same to hawks and owls, indicating highly effective leg muscle groups and toes that can also grip and potentially raise proportionally unprecedented prey, same to some standard raptorial birds.
“Essentially essentially based on clues in their foot bones, we mediate these birds would were ready to get and lift prey, same to what a contemporary hawk or owl does,” talked about Alex Clark, a Ph.D. scholar at the Field Museum and the University of Chicago.
“While they’ll also no longer be the first birds of prey to ever evolve, their fossils are the earliest known examples of predatory birds.”
The unique species win higher the known diversity of Unhurried Cretaceous birds, verify the kind toward unprecedented body size, and highlight how, over time, enantiornithines developed a greater diversity of ecological roles.
“Avisaurids, a community of enantiornithine birds from the latest Cretaceous, rate hindlimb parts indicating solid ankle flexion, which implies the capacity to withhold heavy prey and behaviors same to residing raptorial birds,” the paleontologists talked about.
Their paper looks this day in the journal PLoS ONE.
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A.D. Clark et al. 2024. Fresh enantiornithine diversity in the Hell Creek Formation and the handy morphology of the avisaurid tarsometatarsus. PLoS ONE 19 (10): e0310686; doi: 10.1371/journal.pone.0310686
