A near-perfect fossilized cranium found in Antarctica reveals the bridge between prehistoric and fashionable birds, a brand new examine has discovered.
The fossil is a specimen of a species known as Vegavis iaai, which lived round 69 million years in the past – greater than 2 million years earlier than the mass extinction that worn out all non-avian dinosaurs.
It has a protracted pointed beak and a mind form in contrast to some other Mesozoic birds, which had been markedly totally different from species that may evolve into the category of feathered creatures we see round us as we speak.
Ever since Vegavis was described 20 years in the past, some paleontologists suspected the genus is perhaps an early member of contemporary birds, inside the order of waterfowl. Others doubted it since fashionable birds had been extraordinarily uncommon previous to the asteroid influence that triggered the end-Cretaceous extinction.
However they had been lacking what’s arguably a very powerful piece of Vegavis, at the least on the subject of taxonomy: a somewhat-intact cranium.
“Few birds are as likely to start as many arguments among paleontologists as Vegavis,” says lead writer Christopher Torres, a paleontologist from Ohio College.
“This new fossil is going to help resolve a lot of those arguments. Chief among them: where is Vegavis perched in the bird tree of life?”
Chicken fossils could be fairly delicate, and few from this time are preserved in such fine condition as this one. All different Vegavis specimens discovered up to now have been both skeletons sans head, or simply bits of the cranium.
The researchers suspect the species could have survived the mass extinction due to their Antarctic location, which might have provided a temperate local weather with lush vegetation at a time when the remainder of the world was fairly uninhabitable.
“Elsewhere globally, the rapid environmental upheaval characterizing the K–Pg boundary is generally marked by similarly rapid replacement of stem birds by crown birds, followed by diversification of the latter early in the Palaeogene,” the authors write.
That makes V. iaii one of the best consultant now we have for the bridge between prehistoric and fashionable birds.
The researchers used X-ray micro-computed tomography to scan the cranium and digitally reconstruct it in three dimensions, revealing particulars of its braincase, palate, rostrum and mandible, in addition to its mind form.
The specimen hints at options in step with fashionable waterfowl, however in contrast to the geese and geese of as we speak, V. iaai additionally had a slender, pointed beak and highly effective jaw muscle tissues for snapping up fish: options which are extra just like these of diving birds of as we speak like grebes and loons.
It has a well-developed salt gland within the nasal area of its beak, a characteristic that removes sodium chloride from the blood of some marine chicken species with diets excessive in seafood and, consequentially, salt.
The remainder of the fossil skeleton builds on this image of V. iaai‘s aquatic life-style, with legs that positioned the ft to propel the chicken by means of the water in pursuit of swimming prey.
“Those few places with any substantial fossil record of Late Cretaceous birds, like Madagascar and Argentina, reveal an aviary of bizarre, now-extinct species with teeth and long bony tails, only distantly related to modern birds,” says paleontologist Patrick O’Connor from Ohio College.
“Something very different seems to have been happening in the far reaches of the Southern Hemisphere, specifically in Antarctica.”
This analysis was revealed in Nature.
