Some were as small as pigeons. Others had bodies as big as a single-engine airplane.

Pterosaurs ruled the skies for more than 150 million years, a remarkable span, from the Triassic to the Cretaceous. They were the first animals with backbones to take flight.

They shared the Earth with dinosaurs, but they weren’t dinosaurs themselves.

We’ve known about pterosaurs since the first fossils were discovered in the late 1700s. But scientists are still learning new things about them, from how well they could fly and their behavior while on the ground to what colors their elaborate head crests might have been.

If you’re as fascinated by pterosaurs as I am, you’ll love today’s show.

Our guest is Dr. Mark Norell, curator and chair of the Division of Paleontology at the American Museum of Natural History in New York.

Dr. Norell is an internationally known paleontologist whose research focuses on the evolutionary relationships between dinosaurs and modern birds. He has hunted for dinosaur fossils in in Mongolia’s Gobi Desert, Patagonia and the Chilean Andes in South America, and the Sahara Desert in North Africa. He’s made major fossil discoveries, including the first embryo of a primitive meat-eating dinosaur, and an Oviraptor found nesting on a brood of eggs, which constituted the first evidence of parental care among dinosaurs.

Dr. Norell is the co-curator of the traveling exhibit “Pterosaurs: Flight in the Age of Dinosaurs,” which is on display at the Cleveland Museum of Natural History through August 12, 2018.