Published: Fri, May 04, 2018
Science | By Joan Schultz

It's a bird. It's a ... dinosaur?

It's a bird. It's a ... dinosaur?

After analyzing the CT scans and comparing them against earlier fossils, the researchers found that Ichthyornis was not unlike modern birds in the way it moved its beak, as it was able to lift its upper beak without having to move the rest of its skull. Most of its fossils have been found in sedimentary rocks that accumulated in a broad seaway that once stretched from the Gulf of Mexico to the Arctic Ocean, says Bhart-Anjan Bhullar, a vertebrate paleontologist at Yale University and co-author of the study.

Ichthyornis dispar lived almost 100 million years ago in North America, looked something like a toothy seabird, and drew the attention of such famous naturalists as O.C. Marsh (who first named and described it) and Charles Darwin.

It is the fossils of an ancient bird known as Ichthyornis Dispar which offered a better understanding of the evolution of birds. For instance, every time someone makes a comment about dinosaurs being extinct, you can just chime in and say that dinosaurs aren't gone - they're all around us.

Field hopes these recent discoveries will prompt fossil hunters to recover yet more dinosaur-era bird skulls.

A three-dimensional representation of fossils of the Ichthyornis dispar revealed how the dinosaurs transitioned to modern-day birds with beaks.

There are, of course, dramatic differences between birds and dinosaurs. The research team carried out complete CT scans, reconstructing the bird's skull.

Dr Steve Brusatte of the University of Edinburgh, who is not connected with the research, described the study as a game-changer in how we understand the evolution of the bird beak and brain.

The seagull-sized bird had a beak and a brain much like modern birds, but the sharp teeth and powerful jaws of dinosaurs like Velociraptor. This unusual mix of features would have enabled preening and object manipulation after arms became wings, and goes to show that the feeding apparatus of living birds evolved earlier than previously thought.

Scientists first discovered Ichthyornis in the 1870s, but the first fossilised specimens were crushed and incomplete.

The brain was also relatively modern, but the temporal region was unexpectedly dinosaurian. The creature did, however, also have teeth and a jaw with enough muscles to effectively use those teeth, two things modern gulls don't. This study has revolutionized the knowledge concerning the origin of the avian beak.

"Bird brains are larger relative to their body size than is the case for reptiles, and the relative size of bird brains is comparable to that of placental mammals", paleontologist Kevin Padian of the University of California, Berkeley, says in response to the study published today in the journal Nature.

The combination of traits that this creature possessed could have been the key to answering this question. This is in contrast to velociraptors and other dinosaurs whom birds are believed to have evolved from, where the animals had tiny brains in relation to their body. While we still don't know all those things, this attractive reconstruction provides a valuable stepping stone for future studies, and will undoubtedly serve as a resource for future paleontological studies.

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