A small, fossilized mammal had what appears to be poisonous fangs that allowed it to bite like a snake – the first such find in an extinct mammal, Canadian researchers say.

Vertebrate paleontologist Richard Fox of the University of Alberta in Edmonton found the specimen in 1991. Now Fox and his research team say the extinct, mouse-sized creature was built to deliver venom.

The world is home to few living mammals with venom delivery systems: the duck-billed platypus, the Caribbean solenodon, and a few rat-like shrews.

The fossil specimen, Bisonalveus browni, is shown in this recent handout photo. (CP photo)

Scientists concluded that mammals long ago lost the ability to release venom to defend themselves or find food, given how few mammalian species still use the strategy.

The 60-million-year-old fossil of the mouse-sized creature, called Bisonalveus browni, has a deep groove in its upper canine. The length of the tooth may have allowed it to act like a piercing fang, like those found in modern venomous snakes.

"Our discoveries therefore show that mammals have been much more flexible in the evolution of [venom delivery systems] than previously believed," the team concluded in Thursday's issue of the journal Nature.

The fossil teeth were found at two sites in the Paskapoo Formation of central Alberta, an area rich in well-preserved mammalian fossils.

The study shows how even after scientists work on a research project for years, uncovering one small piece of information can lead to new discoveries, Fox said.

The Natural Sciences and Engineering Research Council of Canada and the University of Alberta sponsored the research.