Skip to main content Accessibility help
×
Hostname: page-component-78c5997874-94fs2 Total loading time: 0 Render date: 2024-11-09T22:41:33.892Z Has data issue: false hasContentIssue false

10 - Variation in Tyrannosaurus rex

Published online by Cambridge University Press:  07 September 2010

Kenneth Carpenter
Affiliation:
Denver Museum of Natural History
Philip J. Currie
Affiliation:
Tyrrell Museum of Palaeontology, Alberta
Get access

Summary

Abstract

Individual variation for the large theropod Tyrannosaurus rex may be seen in the maxilla, dentary and ischium. The maxilla is variable in its depth, the size and shape of the maxillary and antorbital fenestrae, and the size and shape of the lacrimal and jugal processes. Even the left and right maxillae of the same skull show variation. Sexual dimorphism is suggested by the presence of two morphs, one more robust than the other. The angle between the ischia and caudals of the robust morph is greater than in the slender morph, and would provide ample space for the passage of eggs. On this basis, the robust morph is considered the female.

Introduction

The large theropod, Tyrannosaurus rex, was named by Osborn in 1905 on the basis of a partial skull and skeleton from the Hell Creek Formation of eastern Montana. The holotype (AMNH 973) was later transferred to the Carnegie Museum of Natural History (CM 9380) where it is presently on display. A second specimen (AMNH 5866) from the Lance Formation of eastern Wyoming, was named Dynamosaurus imperiosus by Osborn (1905) but later synonymized with T. rex (Osborn, 1906). This specimen [BM(NH) R7994 and R7995] is now mounted at the British Museum (Natural History). Numerous additional specimens have since been recovered from the Scollard and Willow Creek formations of Alberta, the Hell Creek Formation of North Dakota, South Dakota, and Montana, and the Laramie Formation of Colorado. These specimens are presently under study by Robert Bakker, Philip Currie, Ralph Molnar, Greg Paul, and myself.

Type
Chapter
Information
Dinosaur Systematics
Approaches and Perspectives
, pp. 141 - 146
Publisher: Cambridge University Press
Print publication year: 1990

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Save book to Kindle

To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Available formats
×

Save book to Dropbox

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.

Available formats
×

Save book to Google Drive

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.

Available formats
×