Burke Museum paleontologists Liz Nesbitt and Christian Sidor answer questions about their favorite fossil and dinosaur. Learn fun facts about Stegosaurus stenops and then come see our own Stegosaurus.

Title: Curator, Burke Museum Invertebrate Paleontology, and Chair of the Division; Affiliate Assistant Professor, UW Earth and Space Sciences.

Q: What is the oldest fossil you have ever found?

A: Trilobites from the early Cambrian in eastern Washington, 530 million years old.

Trilobites ("TRY-loh-bites") were only common in the earliest Paleozoic seas. They are arthropods (the large group of invertebrate animals that includes insects, spiders, and crabs). Trilobites scurried around the seafloor eating tiny pieces of food lying on the mud. Their closest living relatives are the horseshoe crabs.

From Life and Times of Washington State Exhibit Guide, By Liz Nesbitt and Ruth Pelz

Q: What type of fossils have you wanted to find, but haven't?

A: Giant sea reptiles in Washington State, like the Plesiosaur and Mosasaur on display in the museum.

Title: Curator of Vertebrate Paleontology;
Assistant Professor UW Biology.

Q: What is your favorite dinosaur?

A: Triceratops. The name means "three-horned face" and it lived during the Cretaceous period, about 65 to 75 million years ago. Triceratops had the biggest head of any land-living animal, a heavy frill, and a strong neck. Scientists think that the frill of Triceratops was probably used as a display, like bright feathers of some birds. The three horns of Triceratops were probably used for defense. In the museum you can find a Triceratops skull pieced together by our fossil preparator Bruce Crowley.

Q: Why are dinosaurs extinct?

A: Scientists think that about 65 million years ago a giant asteroid hit the Earth. This impact set off a chain of events like fires, acid rain, and global climate change that eventually killed off many animals. Maybe 70% of the animals on Earth died, including many types of large dinosaurs. However, one group of relatively small dinosaurs survived—birds!