Dissacus is a paraphyletic extinct genus of faunivore jackal to coyote-sized Mesonychidae, a family of hoofed mammals part of the extinct order Mesonychia. Their fossils in Early Paleocene to Middle Eocene aged strata in Eurasia and North America. Dissacus europaeus likely evolved from a population of North America Dissacus that migrated to Europe, and first appeared in European strata in the Thanetian. A phylogenetic analysis of European mesonychids suggests that Dissacus was part of an early diversification of species in the Paleocene, and other genera diversified in a later episode in the early Eocene. D. europaeus survived the Paleocene-Eocene Thermal Maximum, a period of severe global warming, which suggests it had flexible habits. Orientation patch analysis of the molar teeth of the North American D. praenuntius suggests its faunivore with consisted diet consisting of meat, although it wasn’t a hypercarnivore such a felid or weasel, instead having a diet similar to brown hyenas where insects and plant matter made up a small proportion of its diet. It shared its environment with other omnivorous mammals of a similar body size such as Palaeonictis, although Dissacus had a greater preference of meat.