First Dinosaur Fossil Found in Washington State | KUOW News and Information

First Dinosaur Fossil Found in Washington State

May 20, 2015

A large bone from a two-legged, meat-eating dinosaur has been discovered in the San Juan Islands – the first dinosaur fossil ever found in Washington state.

Researchers found the fossil by accident. In 2012, they were in Sucia Island State Park collecting sea creature fossils when they stumbled on a bone that looked unusual for that area.

A month later they returned to the site with paleontologists. Initially, Professor Christian Sidor of the Burke Museum didn’t believe it belonged to a dinosaur.  

But one feature of the bone convinced Sidor, a professor of biology at the University of Washington and vertebrate curator at the Burke Museum: “The muscles that actually attach to the back of the leg and retract the femur attach here. So this structure, the shape of it, and how close it is to the head of the femur tell us that this is a carnivorous dinosaur. All dinosaurs have this feature.”  

The scientists don’t know what kind of dinosaur the bone comes from, however, because there’s only a third of the bone. Sidor said it’s likely a therapod, which includes Tyrannosaurus rex, birds and Velociraptors. And they are pretty sure it is from the Late Cretaceous period and is about 80 million years old.

The partial thigh bone measures 16.7 inches long and 8.7 inches wide. Scientists believe the complete bone was likely more than three feet long.

It is unclear if the dinosaur comes from the Pacific Northwest or from further down the West Coast.

“It could Washington’s first dinosaur from Mexico; it could be Washington’s first dinosaur from California, or from Oregon," Professor Christian Sidor said.

The dinosaur fossil was found in the San Juan Islands, which is unusual because dinosaurs were land creatures. It indicates that perhaps the rock came from further south on the West Coast, perhaps Baha Mexico.
Credit Burke Museum

Sidor and Brandon Peecook, a University of Washington biology graduate student, described their fossil discovery in a journal article.

Said Peecook: “This specimen, though fragmentary, gives us insight into what the West Coast was like 80 million years ago, plus it gets Washington into the dinosaur club.”

With this discovery, Washington becomes the 37th state where dinosaurs have been found. To be fair, Washington was mostly underwater when dinosaurs roamed the earth. In a statement, the Burke explained that it is unusual to find dinosaur fossils in marine rocks because they were land animals. 

The San Juan Island beach where the partial dinosaur femur was found.
Credit Burke Museum