A small mammal that lived around 60 million years ago had poisonous fangs that enabled it to bite like a snake, the first time that an extinct mammal species has been found with this capacity, a new study says.
The fossilised remains of two curved canines, found in the Canadian province of Alberta, shows a groove from which the creature, Bisonalveus browni, probably shot venom into its prey.
Only a small number of modern mammals, including the duck-billed platypus and a rat-like creature called the Caribbean Solenodon, use venom delivery.
That rarity had led experts to conclude that, early in their evolution, mammals discarded the potential of venom as a way of defending themselves or getting food.
The discovery suggests, though, that mammals may have been far more flexible than was previously thought.
Some species must have developed special venom glands and the systems to deliver the poison, although how and why these evolved characteristics died out remain unclear.
The study, headed by University of Alberta palaeontologist Richard Fox, is published in Thursday's issue of Nature, the British weekly science journal.
(c) 2005 AFP
