Paleontologists from the University of Washington’s Burke Museum of Natural History and Culture have reportedly located the first dinosaur fossil ever discovered in that state: A fossil described by the team as the partial left femur of a two-legged carnivorous theropod.
UW researchers Dr. Brandon Peecook and Dr. Christian Sidor, who detailed their findings in a paper published in the journal PLOS One, made the discovery while collecting fossils along the shores of Sucia Island State Park in the San Juan Islands.
The duo was collecting fossils of ammonites (nautilus-like creatures) at a marine rock area called the Cedar District Formation when they found a 16.7 inches long, 8.7 inch wide fragment of bone that they believe would have been more than three feet long when complete. It belonged to an approximately 80-million-year-old dinosaur from the Late Cretaceous period.
Might belong to a velociraptor
While the bone is incomplete, the study authors report in a statement that it most likely belonged to a theropod because there is a hollow middle cavity in the bone that once would have contained marrow – a feature unique to theropods such as the velociraptor during this time period.
Furthermore, they explained that there is a feature on the surface of the bone (called the fourth trochanter) that is prominent and close to the hip. This combination of characteristics is known to have existed only in some theropods. However, due to the incomplete nature of the fossil, the researchers are unable to identify the exact family and species that the creature belonged to.
“This fossil won’t win a beauty contest, but fortunately it preserves enough anatomy that we were able compare it to other dinosaurs and be confident of its identification,” Dr. Sidor said in a statement. Dr. Peecook added that the new specimen “gives us insight into what the West Coast was like 80 million years ago, plus it gets Washington into the dinosaur club!”
Based on comparison to other specimens, Dr. Sidor and Dr. Peecook were able to estimate that the creature’s complete femur bone would have been about 1.17 meters in length, or somewhat smaller than that of a Tyrannosaurus rex. They found fossilized prehistoric clams in the hollow part of the bone, which indicates that the dinosaur was preserved in marine rock.