Allosaurus fragilis

Photo by Dane Penland

Catalogue number: USNM 4734
Allosaurus fragilis
Collected in 1883 by M.P. Felch, Fremont County, Colorado
Jurassic Period, about 150 million years ago

This specimen measures 21 feet from nose to tip of tail.

M.P. Felch, a collector for both the U.S. Geological Survey and O.C. Marsh of Yale University, collected this specimen in 1883 at Canon City, CO. At the time Marsh studied and named this dinosaur, this specmen was still encased in matrix. It wasn't until 30 years later that it was prepared by Charles Gilmore to study, and nearly 70 more years passed before it was mounted for exhibition by Arnold E. Lewis in 1981.

During its lifetime this animal broke its left scapula (shoulder blade), but there are no tooth marks or missing bone pieces to indicate that it happened during a fight with another dinosaur. According to David Norman in his book The Illustrated Encyclopedia of Dinosaurs, Allosaurus was not built for high-speed chases. They probably preyed upon large herbivorous dinosaurs such as Camptosaurus and Stegosaurus. It was one of the largest flesh-eating dinosaurs (about 30 feet long) that lived during the Jurassic Period, over 140 million years ago.

*This skeleton was featured on the cover of the book, Prehistory of the Far Side, by Gary Larson.

For more information see:

Farlow, J.O. and M.K. Brett-Surman, (eds) 1997. The Complete Dinosaur. Indiana University Press (Bloomington, IN), p. 752.

Also, click here to see additional Allosaurus exhibits:

Foot

Injury

Pelvis