Most carnivorous bat

The most carnivorous bat was probably the death-eater (Necromantis adhicaster), a large prehistoric species known from fossil remains obtained in the mid/late Eocene deposits of France's Quercy Phosphorites Formation, and therefore dating back approximately 40 million years. Unique among all bats, present and past, were its carnassials – paired upper and lower teeth (molars in this species) modified to permit enlarged and often self-sharpening edges to pass by each other in a shearing manner, thus enabling the animal to slice through flesh with ease. Only truly carnivorous mammals possess carnassials, which have evolved independently in several different mammal groups, so there can be no doubt that the death-eater was truly carnivorous, although whether it killed and devoured live prey or merely scavenged upon already dead carcasses is presently unclear.

The size of its skull (apart from a single fossil forearm bone, no post-cranial remains have so far been found for it), approximately 3.2 cm (1.2 in), plus its sturdy jaws and masseters (chewing muscles) – and an estimated total body weight of 47 g (1.6 oz) – suggest that the death-eater was quite sizeable and therefore powerful enough to seize and carry off small mammals, reptiles, birds and perhaps even other bats as prey. More recently, fossils of a smaller but closely related death-eater species have been recovered from deposits in Tunisia, showing that these distinctive bats exhibited a wider distribution range that originally assumed.