North America

For the paleontologist Ben Kigman, the question was: Is this fragile jawbone a pterosourium or not?

Other researchers also had questions about the fossil, unearthed along with thousands of others during an archaeological excavation of decades in a bed of remote bones in the Petrified National Park in Arizona. Some thought the bone could have been a mammal, Kigman told News themezone.

Now, his new research offers information on the oldest known flying reptile in North America that Kigman and other paleontologists say it was the size of a “small seagull.”

The article led by Smithsonian, published on Monday in the minutes of the Magazine of the National Academy of Sciences, details the new Pterosour fossil discovery along with several others, providing information on the late Triassic period.

Kigman remembers looked at the jaw under a microscope in the Smithsonian, where he is a postdoctoral fellow of Peter Buck and where the fossil had been sent, and crossing his “Rolodex” of anatomy of the Triassic jaw, thinking about what species a similar jaw could have. I wanted to solve the mystery from where the delicate jaw belonged.

Through the elimination process and thinking about the characteristics that the pterosaurs have that no other animal has, Kigman said that he and other researchers could conclude that: “Oh, yes, this is definitely a pterosour, therefore, this is a very important discovery.”

The team appointed the pterosaur the eotephradactylus mcintiree, which means “goddess of ashes dawn.” The name of the species refers to its discoverer, Suzanne McIntire, who volunteered in the Fosilab de Smithsonian for 18 years.

McIntire discovered the Pterosaur fossil, which had been taken to the Petrified Forest National Park Museum along with another 1,200 individual fossils, including bones, teeth, fish scales and coprolites, or fossilized excrement.

Volunteers thoroughly clean each fossil, interest flag and perform other fossil conservation tasks. McIntire unearthed his jaw and noticed that the teeth were still in the bone, which facilitated identification.

Winged reptile, a close cousin of dinosaurs and the first animals after insects to evolve the flight with food, would have been small enough to perch comfortably on a person’s shoulder.

“It could have sat on the shoulder, like a small seagull,” Kigman said about the species.

The researchers were able to go out with the fossil 209.2 million years ago, an unusually precise date, Kigman said, due to the level of volcanic ashes where the fossil was found. The finding helps to fill a vacuum in the fossil record that is prior to the extinction of the final Triassic, he said. Very few pterosour fossils exist, Kigman said. After its extinction, its fragile bones are badly preserved, so pterosour fossils are frequently incomplete. Nor did they live near places where fossils tend to form.

“It helps us understand what a pterosour was and how they became what they would become,” Kigman said.

Together with the pterosaur, the study also detailed other findings, including one of the world’s oldest turtle fossils, giant amphibians and armored crocodile relatives, which lived along with evolutionary advertising such as frogs, turtles and pterosaurs.

• Smithsonian
• Arizona
• Science