New Thinking About Wyoming's Middle Jurassic Dinosaurs

["Richard W. Travsky" <rtravsky@uwyo.edu>]

http://uwadmnweb.uwyo.edu/NEWSLETTER/jurassic.htm

University of Wyoming undergraduates have discovered new evidence for the
existence and behavioral activities of dinosaurs in a time and place never
previously suspected in North America.

Research findings at the Yellow Brick Road Dinosaur Tracksite in the
Bighorn Basin show that 167 million years ago (Middle Jurassic period)
dinosaurs roamed an area of Wyoming that was believed to be underwater. An
article about the tracksite research co-written by Thomas Adams of Shelby,
Iowa (a geology/geophysics and zoology/physiology senior) and Brent
Breithaupt (UW Geological Museum director) appears in Wyoming Geo-Notes
No. 78, published by the Wyoming State Geological Survey (WSGS). A
previous article about the research methodology and site documentation was
published by Adams and Breithaupt in Geo-Notes No. 76.
...
Breithaupt says the tracksite study has furnished opportunities for
undergraduate students to contribute significantly to scientific knowledge
that increases the understanding of an important time period in dinosaur
evolution.

"This research provides a snapshot of a unique period millions of years
ago," Breithaupt says. "Most of the tracks were made within a short period
of time by family packs of carnivorous dinosaurs traveling together.
Footprints like those found in the Bighorn Basin allow us to put together
stories about dinosaur communities and make new interpretations about
Wyoming at that time."

Prior to the discovery of the tracks at the Yellow Brick Road Tracksite
and the nearby Red Gulch Dinosaur Tracksite, it was believed that much of
what is now Wyoming rested under a large, shallow inland sea, called the
Sundance Sea, that covered much of North America approximately 165 million
years ago.

Thousands of tracks at the site were apparently made by made by
two-legged, three-toed meat-eating dinosaurs that traveled along the mucky
shores of the sea.

Since few dinosaur remains from the Middle Jurassic have been found
anywhere, the Yellow Brick Road Dinosaur Tracksite research is especially
noteworthy, Breithaupt says. "We go from knowing almost nothing about
dinosaurs during this time period in Wyoming to this site and others that
provide an exciting and expansive resource to understanding the Middle
Jurassic. In addition, the trackways are evidence of these animals'
activities when they were alive, as opposed to the fossilized bones and
teeth."

The opportunity for undergraduate student involvement in the tracksite
study is a major benefit of this research. Since 2001, UW students and
volunteers have studied thousands of footprints at the site.

Adams, the primary researcher at Yellow Brick Road, took detailed
measurements of hundreds of tracks. He documented the site using
state-of-the art methodologies, including aerial photographs taken from a
blimp and satellite imagery.
...