(ORDO NEWS) — Paleontologists have discovered in Belgium fragments of the skeleton of a fossil bird, hiding in a piece of rock the size of a grapefruit.
The new species turned out to be a primitive seabird whose beak combined teeth inherited from dinosaur ancestors and a movable palate characteristic of most modern birds.
Modern birds are divided into two main groups: ratites, or paleognaths (Paleognathae, “ancient jaw”), and new-palatine, or neognathae (Neognathae, “new jaw”).
Most of the current birds belong to the latter, and their key feature, as the name implies, is the unfused bones of the palate, which give the beak greater mobility.
It has long been assumed that the structure of the beak of neopalates is a relatively recent evolutionary acquisition, and in the era of dinosaurs, all birds had a fused beak, like those of today’s ostriches. However, a new discovery near the Belgian-Dutch border has disproved these notions.
The new species was named Janavis finalidens : the bird lived 66.7 million years ago, at the very end of the dinosaur era, weighed about one and a half kilograms and was one of the last toothy birds on Earth.
Although the Yanavis had sharp, dinosaur-like teeth in its beak, it had a movable palate, just like modern geese and ducks. Thanks to this, Yanavis could clean plumage and catch slippery fish just as well as modern birds.
Since it occupies a position on the evolutionary tree of birds close to the direct ancestors of modern birds, scientists have come to the conclusion that the “ancient jaws” of modernity – ostriches, emus and cassowaries – are not at all as primitive as we think.
Surprisingly, since the time of Thomas Huxley , “Darwin’s bulldog”, who first identified these two groups of birds, no one has particularly questioned the “primitiveness” of paleognaths and the “progressiveness” of neognathans – largely due to the scarcity of fossil bones found.
And now, at last, janavis has been able to fill the necessary gap in the evolutionary history of birds.
In other words, the fused palate of paleognaths is a “return to the roots” that occurred after the extinction of the dinosaurs and the formation of modern-type birds.
While scientists cannot say why the structure of the beak in ostriches backpedaled, so new finds of the direct ancestors of modern paleognaths will be required to reveal the features of their evolutionary history.
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