Fossil Shows Poison-Biting Small Mammal

A Canadian university student has discovered a fossil of a 60 million-year-old mouse-like mammal that had a rare, poisonous bite.

Doctoral student Craig Scott was sorting through a box of fossils at the University of Alberta in Edmonton when he made the find, the Chicago Tribune said.

Scott and a lab technician first noticed a groove along the upper front canine teeth on the recovered jaw of a Bisonalveus browni.

Scott said he first thought the groove was a cavity, but then realized it was a system for delivering venom.

The groove in these teeth would have acted as a gutter, conducting fluid from its source in glandular tissues in the upper jaw down the height of the crown to its tip, he said.

His professor, vertebrate paleontologist Richard Fox agreed.

Our discovery shows that mammals have been much more flexible in the evolution of venom delivery systems than previously believed, Fox said.

The discovery is described in the Thursday issue of the research journal Nature.