The vast majority of photographs are thumbnails... Please click on them to see a larger version
Cryptocleidus, a small, long neck
plesiosaur from Great Britain
Trinacromerum sp.
A shortnecked plesiosaur, generally
referred to as a pliosaur. The primary species of
plesiosaur found in this quarry.
This is an attempt to show the work being
done on this site in Grant County, South Dakota from a
paleontological standpoint. This is an active working
quarry and it is sometimes impossible to get in to work due
to the use of explosives in the quarrying. St. Cloud State
University of St. Cloud, Minnesota, has been studying this
site for the last several years, under the leadership of
Dr. Standley Lewis of the Biology Department of SCSU. Some
of the findings over the past few years includes shark
teeth and vertebrae, bony fish skulls,teeth, vertebrae, and
a partial vertebral column, gastropod shells, belemnites, a
few unknowns, two looking like bones from a large
dinosaurian, a couple hadrosaur teeth, and the focus of
this page, plesiosaur remains, with many fossil propodials,
teeth, and vertebrae. A basioccipital was also found along
with various types of ribs. The site was in the past a
boulder strewn beach on an island in the Western Interior
Seaway, which covered most of the center of the United
States during the Mesozoic Age. It's been dated as Turonian
(late Cretaceous) from the Carlile Formation, or about 90
million years old. This following pages will show some of
these fossils, most of which have been identified as
Trinacromerum sp., photos of the site, a few maps, and
drawings from a Masters thesis being done on the site by
Barry Kazmer from SCSU.
Map of Western Interior Seaway from Mike
Everhart at Oceans of Kansas Paleontology
