CLEVELAND -- Mark Norell, author of the award-winning books Discovering Dinosaurs and A Nest of Dinosaurs, has made more than 20 international science expeditions looking for dinosaurs. Norell will give a free public talk at 5 p.m. Tuesday, November 20 in the Thwing Center Ballroom, 11111 Euclid Avenue, at Case Western Reserve University. The College Scholars Program is the sponsor.

The topic of his talk is "The Evolution, Origin and Assembly of Birds: New Evidence from Asia." He will answer such questions as: Why Tyrannosaurs and Velociraptors have many downy feathers to keep them warm? Did dinosaurs develop feathers at the same time that they developed warm bloodedness?

Norell is a curator and paleontologist from the American Natural History Museum in New York City. He will present information about new discoveries about dinosaurs that are adding important new details to our understanding of evolution.

Since age 14, Norell has taken more than 20 international expeditions to Patagonia, Cuba, the Chilean Andes, the Sahara, West Africa, and Mongolia, primarily looking evidence of dinosaurs. He has made numerous discoveries about dinosaurs, including dinosaurs with feathers and evidence of their nesting on a clutch of eggs like birds. He also has named several species.

Discovering Dinosaurs (1995) won Scientific American's Young Readers Book of the Year Award, and A Nest of Dinosaurs received the Orbis Pictus award from the National Council of Teachers as a noteworthy title.

For more information, call 216-368-0528.