Edmontosaurus annectens

Scientific Name: Edmontosaurus annectens

Phylum: Chordata

Class: Dinosauria

Ornithischia

Hadrosauria

Ruth Mason ranched (she died in 1990) near Faith, South Dakota, a prairie community 100 miles northeast of the Black Hills. When she was seven years old, she discovered a bed of ancient bones weathering out of a bluff a few miles from her folks' house. For eighty years she attempted vainly to interest researchers in her find. In the spring of '79, Pete and Neal Larson met Ruth and were taken to the bones. Near the channel of the Moreau River, in a bluff cut by the river, was the graveyard of what appeared to be hundreds of dinosaurs. In a bed about eighteen inches thick, bones were found almost everywhere the Larsons probed with a digging knife.

The Larsons are still working this find, which they called the Ruth Mason Quarry. The find contained the remains of at least two thousand Edmontosaurus annectens, all disarticulated. There is only speculation as to the reason so many bones were in one place. The river system could have transported the bones a few at a time to a sandy coast at the edge of a receding Cretaceous sea. Or a great storm could have trapped and drowned a herd on a spit of land. Various carnivores teeth, including that of T. rex, were also found at the site, which could simply mean that these beasts were scavenging the remains.