Osteology of a large allosauroid theropod from the Upper Jurassic (Tithonian) Morrison Formation of Colorado, USA

Journal Title: Volumina Jurassica - Year 2014, Vol 12, Issue 2

Abstract

Two partial skeletons of allosaurid theropods belonging to an adult and a juvenile from the Upper Jurassic (Tithonian) Morrison Formation of McElmo Canyon in Montezuma County, southwestern Colorado, were discovered in 1953 by the late Joseph T. Gregory and David Techter. The adult specimen consists of several isolated cranial and postcranial skeletal elements that are exceptionally well-preserved and include the left premaxilla, maxilla, dentary, teeth, quadratojugal, two caudal vertebrae, pubic peduncle, ischium, proximal tibia, a nearly complete left foot, and several isolated teeth, whereas the juvenile specimen is represented by the distal portion of the right dentary and a fragmentary splenial. The specimens represent a new species of [i]Allosaurus[/i], here named [i]Allosaurus lucasi[/i], which differs from [i]Allosaurus fragilis[/i] by having a relatively short premaxilla and robust quadratojugal with short jugal process and a short quadrate process of the quadratojugal that is at the same level as the rostral quadratojugal ramus. The presence of a new species of [i]Allosaurus [/i]in the Tithonian of North America provides further evidence of the taxonomic and morphological diversity of the Allosauridae clade and their continuous evolutionary success, which extended to the Cretaceous.

Authors and Affiliations

Sebastian G. DALMAN

Keywords

Related Articles

Additional Tithonian and Berriasian ammonites from the Vaca Muerta Formation in Pampa Tril, Neuquén Basin, Argentina

The ammonite fauna of the Tithonian–Berriasian of the Vaca Muerta Formation in Pampa Tril has been recently described in detail. New important specimens and additional information are presented in this paper. The phyleti...

BUSINESS INTELLIGENCE IN MANAGING THE HOSPITAL

In the article was presented the conception of the Intelligence Business in the context of functioning of a managerial computer system at the public hospital, with particular reference to using the specific System of Man...

The stratigraphy and palaeogeographic position of the Jurassic successions of the Priborzhavske-Perechin Zone in the Pieniny Klippen Belt of the Transcarpathian Ukraine

The Jurassic deposits which crop out in the quarries at Priborzhavske, Perechin and Novoselitsa in the Transcarpathian Ukraine comprise fairly similar successions, allowing their interpretation as corresponding to a sing...

Download PDF file
  • EP ID EP67990
  • DOI 10.5604/17313708 .1130141
  • Views 58
  • Downloads 0

How To Cite

Sebastian G. DALMAN (2014). Osteology of a large allosauroid theropod from the Upper Jurassic (Tithonian) Morrison Formation of Colorado, USA. Volumina Jurassica, 12(2), 159-180. https://europub.co.uk./articles/-A-67990