Look up: Helicoprion

1. Helicoprion
   Helicoprion was an ancient fish from the Late Paleozoic (it appeared during the Carboniferous period, about 345 million years ago). This predatory fish is known only from fossilized teeth; it probably had a cartilaginous body (which does not fossilized well and is possibly why a fossil skeleton from...
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2. Helicoprion
   `Helicoprion` ("Spiral Saw") was a long-lived genus of shark-like cartilaginous fish that first arose in the oceans of the late 280-->, survived the Permian-Triassic extinction event|Permian-Triassic Extinction Event, and eventually went extinct during the early Triassic some . The ...
   Found on http://en.wikipedia.org/wiki/Helicoprion