Date of Award
Master of Science (MS)
Dr. Richard J. Zakrzewski
A disarticulated skeleton of a theropod from the Late Jurassic (Tithonian) strata of McElmo Canyon in Montezuma County, Colorado was discovered in 1953 by the late J. T. Gregory and D. Techter. For nearly 55 years the specimen remained unnoticed in the collection of the Yale Peabody Museum of Natural History in New Haven, Connecticut. Several cranial and postcranial elements are relatively well preserved and include the premaxilla, maxilla, dentary, teeth, quadratojugal, braincase, metacarpals, partial pubis and ischium, astragalus, partial tibia and fibula, metatarsals, pedal phalanges, and several partially preserved ribs. The specimen represents a new genus and species of basal carcharodontosaurid, which shares some morphological similarities with Late Jurassic allosaurids. As such, the new genus and species is the first unequivocal carcharodontosaurid from the Late Jurassic of North America. The presence of a North American carcharodontosaurid during the Late Jurassic provides evidence that the clade may have originated on that continent and that the Carcharodontosaurids split from the allosaurids in the Middle or Early Jurassic.
Dalman, Sebastian, "A new Carnosaur (Dinosauria: Theropoda) from the Upper Morrison Formation (Late Jurassic, Tithonian) of Colorado" (2010). Master's Theses. 165.
Copyright 2010 Sebastien Dalman