Fig. 5.2.

An impression of the remarkably complete skeleton of a borhyaenid (Lycopsis longirostris). This 15 kg animal was likely an ambush hunter, stalking small-to medium-sized prey. We know that it fed on mammals because fragmented rodent bones and teeth have been found in the stomach cavity of Lycopsis fossils. It was likely not a fast runner, but an ability to invert its hind foot and grasp branches might have allowed it to occasionally escape larger predators of the time. Note the very large head, a common feature of many borhyaenids. Early fossils, consisting only of skull fragments, suggested that borhyaenids were huge, larger than grizzly bears. However, more complete skeletons such as this one suggest they had unusually large heads and their total body weight may have only rarely exceeded 100 kg. The long, low-slung skull suggests these animals may have resembled members of the carnivorous placental mustelid family, such as weasels and martins. Source: Andrew Baker.