In the
Early to Mid-Cretaceous Period, 100 to 125 million years ago, large
meat-eating dinosaurs roamed the flat muddy shoreline that is now
southeastern Oklahoma. Among these dinosaurs was Acrocanthosaurus
atokensis, whose name means “high-spined lizard”.
This dinosaur lived about 45 million years before the reign of Tyrannosaurus
rex, and is the largest meat eating dinosaur from that era to have
been discovered in North America. Its two outstanding characteristics
are the long spines on its back, and the three claws reaching out
from each forelimb. The claws of Acrocanthosaurus atokensis
measure up to six inches in length and are well designed for capturing
and holding prey, and for tearing flesh from bone.
One of these
ferocious dinosaurs was discovered in 1983 on private land in
McCurtain County. Sid Love and Cephis Hall, paleontologists by
avocation, began to painstakingly excavate the creature’s
fossil remains from a dense, gray mud layer about twelve feet
below the surface. After three years, over 50% of the skeleton
had been recovered, including the skull. Until that time, only
Acrocanthosaurus atokensis limb bones, vertebrae, and
teeth had been found and recorded.
These important
remains were taken to a university laboratory for preparation
and preservation, but stabilization was determined to be too costly
and to take too much time to complete. Meanwhile, the fossils
continued to deteriorate. Finally, with the advice and support
of Allen and Fran Graffham of Geological Enterprises in Ardmore,
Oklahoma, Love and Hall sent the fragile remains to the Black
Hills Institute for Geological Research in South Dakota. Over
a period of five years, specialists worked on them in a dedicated
laboratory space. The costs associated with this work were so
high that it became necessary to sell the fossils. In 1992, the
stabilized remains were purchased by the North Carolina Museum
of Natural Sciences in Raleigh. Molds were made of the ‘bones’
as well as of ‘missing pieces’ to provide complete
cast skeletons for exhibition. The Acrocanthosaurus atokensis
displayed at the Museum of the Red River, which acquired it in
2003, is one of the earliest casts made. |
