From July 18- August 1, 2003, Dr. Matthew Carrano is leading an expedition
to the Late Jurassic deposits of south-central Wyoming. This area
is famous for housing some of the most productive dinosaur sites in
the world, most notably Como Bluff. Most of these sites come from
the Brushy Basin Member of the Morrison Formation, which has produced
such familiar dinosaurs as Apatosaurus, Brachiosaurus,
Diplodocus, Stegosaurus, Allosaurus, Ceratosaurus,
The Morrison Formation is a widespread and thick series of geological strata. It crops out all across the West, representing a varied series of environments with small rivers and floodplains, but in places was seasonally dry or even arid. The earliest layers of the Morrison those below the Brushy Basin Member are not nearly as fossiliferous. As a result, the dinosaurs from these layers are less well known.
Dr. Carrano hopes to locate sites in these early Morrison strata. Such dinosaurs would have lived millions of years before the Brushy Basin forms, but may have included their ancestors. A better sample of early Morrison dinosaurs will provide the means to examine this question, and fossils of other contemporary animals will enable him to look at evolution within Morrison environments over several million years.
Accompanying Dr. Carrano are Drs. Robin O'Keefe and Christian Sidor, both from the New York College of Osteopathic Medicine. They are interested in prospecting the Sundance Formation, which lies just below the Morrison and is therefore older. This formation was deposited by a great inland ocean that covered much of the American West during the Middle Jurassic Period. Dr. O'Keefe hopes to locate plesiosaur fossils in these rocks.