This is a re-creation of a Helicoprion, which lived 270 million
years ago and is the only animal ever with a complete 360-degree
spiral of teeth. By Jennifer Viegas The world’s only animal,
past or present, with a complete 360-degree spiral of teeth was
Helicoprion, which sliced into prey like a buzzsaw. This
sharklike fish, which lived 270 million years ago, is described
in the latest issue of Biology Letters. It had one of the most
unusual mouths and sets of teeth in the animal kingdom. "When
the animal closed its mouth on prey, the spiral of sharp teeth
rotated backwards, like a circular saw, and slashed through the
meat,” lead author Leif Tapanila, an associate professor in the
Department of Geosciences at Idaho State University, told
Discovery News. Tapanila is also the research curator and head
of the Earth Sciences Division at the Idaho Museum of Natural
History. For the study, he and his colleagues took the first
ever 3-D images of Helicoprion remains. Scientists have puzzled
over this animal for more