Parahelicoprion

One of the primary qualities that separate Parahelicoprion from Helicoprion is the shape, thickness, and angle of the tooth whorl. Its teeth protrude outwards not like a tightly coiled saw, but instead a curved arrangement of cutting blades indicating it relied less on crushing slow-moving invertebrates and catching cephalopods, or other small mollusk prey, but inflicting traumatic damage against more durable, faster prey.[2] Their teeth grew at a much slower pace than those of other whorl-tooth sharks, resulting in a depreciated spiral, growing only half of the teeth a Helicoprion would grow in its lifetime. The tooth spiral also was able to indicate the age of the eugeneodontidans in question.[3]

The fossils of Parahelicoprion indicate an animal that was overall similar in size but more slender[4] and less heavy than Helicoprion which measured over 25 ft (7.6 m) in length.[5] Largest Parahelicoprion probably reached 12 m (39 ft) in length,[6] making them along with Helicoprion the largest animals of Paleozoic era.[5][6]

Parahelicoprion is thought to have been a nektonic carnivore that probably preyed upon a variety of different species, using its blade-like teeth to cut at exposed flesh like a hatchet or wedge.[7]