Didelphodon

Didelphodon (meaning "two womb tooth") is a genus of stagodont marsupials from the Late Cretaceous of North America.

Description
Although perhaps little larger than a Virginia Opossum, it was one of the largest mammals of the Mesozoic. The teeth have specialized bladelike cusps and carnassial notches, indicating that the animal was a predator; the jaws are short and massive and bear enormous, bulbous premolar teeth which appear to have been used for crushing.[3]

A recently found specimen, located just 40 m (130 ft) away from a Triceratops in a riverbed, shows the anatomy of Didelphodon. Before the find, only a lower jaw and a partial skull were assigned to the species. This new find shows that Didelphodon possessed an otter-like body with a tasmanian devil-like skull. A study that is being prepared by Kraig Derstler, Greg Wilson, Robert Bakker, Ray Vodden and Mike Triebold will describe this new specimen, housed in the Rocky Mountain Dinosaur Resource Center.

Paleobiology
Fossil evidence suggests Didelphodon was a small predator, perhaps filling the niche that otters do today. A specimen of this stagadont was found to have a skeleton similar to that of an otter yet it had strong jaws suggesting it mostly fed on molluscs. It probably had an omnivorous diet, possible for feeding on molluscs, dinosaur eggs, lizards and plants.