Synoplotherium (synonym Dromocyon) is an extinct genus of relatively small, wolf-like mesonychids that lived 50 million years ago, in what is now Wyoming.

Synoplotherium coexisted with its larger relative, Mesonyx.

[1] The specimen of Synoplotherium on display at the Peabody Museum of Natural History has a fractured lower jaw.

The jaw is cracked right at the midpoint and shows signs of healing.

Evidence in the form of its worn down teeth show the animal survived to old age.