Allosaurus Fragilis: A Revised Osteology (B-109)

By: J. H. Madsen, Jr.

Forty-nine years have elapsed since the initial collection of dinosaur remains by professional paleontologists from the Cleveland-Lloyd Dinosaur Quarry, during which time little descriptive work has been published on this extraordinary site. A massive accumulation of dinosaur bones pertaining to at least eleven genera, and possibly more, lie within the Brushy Basin Member of the Late Jurassic Morrison Formation. Allosaurus Fragilis, the most common taxon, is represented by bones from many individuals of different size. Bones from the Cleveland-Lloyd Dinosaur Quarry are extremely well preserved but from almost completely disarticulated skeletons. Sixty or more individuals are indicated by more than ten thousand elements. Practically every bone of the skeleton of Allosaurus Fragilis from juvenile to adult has been recovered since the first organized excavation in 1927. Growth stages of this species represent individuals ranging from one to four and one-half meters in height and from three to twelve meters in length. The disassociation of skeletal material is an advantage in illustrating and describing contacts and sutures between those bones normally found together or ossified. The variety, preservation, and great number of bones may never be as well represented for any other theropod genus. Although descriptions and illustrations are often of composite bones, they are based on numerous elements. The material is also more than adequate for studies of growth, individual variation, and abnormality.

Other Information:
Published: 1976 (reprinted 1993)
Pages: 163 p.
Location: Emery County
Media Type: Paper Publication