NEW RARE MIDDLE JURASSIC DINOSAUR TRACKSITE FOUND IN NORTHERN
WYOMING Erik P. Kvale 1 Gary D. Johnson 2 Debra L. Mickelson 3
Kate Keller 2 1. Department of Geological Sciences, Indiana
Geological Survey, Indiana University Bloomington, IN, USA 2.
Department of Earth Sciences, Dartmouth College, Hanover, NH,
USA 3. Department of Earth Sciences, University of Colorado at
Boulder, Boulder, CO, USA The Middle Jurassic (159 – 187 million
years ago) dinosaur record is considered sparse worldwide with
relatively little known about dinosaurs from this period.
However, recent discoveries in the Bighorn Basin of northern
Wyoming are changing that with the discovery of the most
extensive Middle Jurassic dinosaur tracksites in North America.
In 1997, near the town of Shell, researchers found extensive
dinosaur track-bearing deposits in 167 million year old rock
once thought to have been totally marine. Now the same
researchers report the presence of an even older more extensive
dinosaur track-bearing layer. The new disco