Dinosaur-Era Bird Fossil Gives Insight Into Birds' Evolution

The well-preserved fossil of a dinosaur-era bird that was discovered in Kansas 148 years ago continues to provide scientists with clues as to how birds evolved from their dinosaur ancestors.

The first delicate fossil of the Ichthyornis dispar, a gull-like bird believed to have lived between 66 and 100 million years ago, was unearthed under the direction of legendary fossil-hunter Othniel Charles Marsh in 1870, according to National Geographic.

It was one of the fossils Charles Darwin referred to as evidence of evolution, because although it resembles modern-day birds in most respects, its beak housed a row of sharp teeth.

After analyzing that and four additional skulls of the Ichthyornis dispar, a team of researchers in the U.S. and the U.K. came up with a well-defined picture of what they believe the bird looked like.

“Now, with greater knowledge, these scientists are showing us just how bizarre the skull of Ichthyornis really was, with an odd combination of derived and primitive features, but many more primitive features than we’d expect,” said Jingmal O’Connor, an expert on early birds at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, China, National Geographic reported.

And in the process, they gained greater insight into the evolution of birds.

“The famous bird archaeopteryx and a lot of the fossils in the early history of bird evolution, they had wings, but their skulls basically looked like little baby dinosaur skulls,” said Dr. Bhart-Anjan Bhullar, a co-author of the research from Yale University, according to The Guardian. “Ichthyornis, it turns out, is just at this transitional moment,” he said, adding that the results “show the order of appearance of modern bird features.”

Unlike modern bird skulls, the toothed upper jaw in Ichthyornis “is very large, and comparable to what you see in a dinosaur like Velociraptor,” said study leader Daniel Field of the U.K.’s University of Bath, according to 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,” Field said. “The new fossils show a surprisingly late retention of a dinosaur-like architecture of the roof of the skull.”

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