Venomous mammals: a review.

The occurrence of venom in mammals has long been considered of minor importance, but recent fossil discoveries and advances in experimental techniques have cast new light into this subject. Mammalian venoms form a heterogeneous group having different compositions and modes of action and are present in three classes of mammals, Insectivora, Monotremata, and Chiroptera. A fourth order, Primates, is proposed to have venomous representatives. In this review we highlight recent advances in the field while summarizing biochemical characteristics of these secretions and their effects upon humans and other animals. Historical aspects of venom discovery and evolutionary hypothesis regarding their origin are also discussed.