Discovery Location: Harding County, South Dakota
Discovered By: Mike Triebold
Diet: Omnivorous Clams and other shelled Invertebrates
Period: Late Cretaceous
Age: 66-65 million years old
Formation: Hell Creek
Lenght: 3 feet
Location of Original Specimen: RMDRC, Woodland Park, CO
This is the only North American mammal skeleton ever found from the late Cretaceous period. The name means “two womb tooth”. It is a marsupial (pouched animal) from the family Stagodontidae. By studying the remains that were found, Didelphodon is thought to have been semi-aquatic. Animals with similar life styles alive today, burrow into the river banks to make their homes. Didelphodon’s diet could have included crawfish, clams, dinosaur eggs, lizards and plants. This animal had an otter-like body. It’s head resembled that of a Tasmanian Devil.
Until this discovery, fossils of Didelphodon consisted only of pieces of skull and jaw. This skeleton was found about 40 feet from a Triceratops skeleton which had come to rest in an ancient riverbed. It is believed that this animal died in it’s burrow and that is why so much of the fossil (roughly 30%) was found. Furthermore, a concretion (fossil hard water stain) was found surrounding the specimen suggesting that it’s burrow was later filled by fluctuations in the water table.
It took a year to identify the bone fragments and three months to build the reconstruction. This will be the subject of a published paper by Dr. Kraig Derstler, Dr. Greg Wilson, Dr. Robert Bakker, Ray Vodden and Mike Triebold.