Unprecedented Fossil Provides New Understanding of Bird Evolution

Paleontologists have just uncovered the remarkably pristine cranium of an ancient bird along with three partial skulls. These remains combine modern and primitive features in surprising ways to capture a fascinating moment in avian evolution.

The Ichthyornis fossils starkly contrast the skeletons of current birds. Modern birds have less musculature in their jaw and larger braincases than their predecessors. Whereas today’s birds have lightweight, toothless snouts, the fossils have large, toothed upper jaws—more comparable to those of dinosaurs. The Ichthyornis specimens even have openings in the top of their skulls, just like in T. rex fossils, to allow for large muscles.

A remarkably intact skull from the dinosaur-era bird Ichthyornis is giving paleontologists valuable insights into avian history.

Here’s John Pickrell, reporting for National Geographic:

“That is a very surprising observation that we would never have expected to make in an animal as closely related to modern bird as Ichthyornis,” [says study leader Daniel Field of the University of Bath in the U.K.] “The new fossils show a surprisingly late retention of a dinosaur-like architecture of the roof of the skull.”

“Bird skulls are at a real premium among paleontologists, as they don’t get preserved in most circumstances,” [Field says]

Paleontologists have been waiting for a discovery like this for decades. Though fossil–hunters have been uncovering Ichthyornis remains since the 1870s, these fossils have usually been compressed almost flat. The new find has finally allowed researchers to create a 3-D model of these skulls in their original shapes.

Some of the fossils are still lodged in rocks, but that hasn’t deterred paleontologists. They CT-scanned the skulls and put together the data they gathered from all of the different fossils to produce a 3-D digital reconstruction.

The researchers hope that this discovery is only the beginning. Though ancient bird skulls are notoriously difficult to find, they’re optimistic that their success will encourage others to continue the search and take up the shovel.