What is "parahelicoprion"

Parahelicoprion is an extinct genus of shark-like eugeneodontid holocephalid from the Permian of the Ural Mountains and South America. Its name is a derivation of Helicoprion, from the Ancient Greek words "Nearly coiled saw", another holocephalid that shares similar traits to it, including the helical whorl of teeth. One of the primary qualities that separate Parahelicoprion from the aforementioned Helicoprion is the shape, thickness and angle of the tooth whorl. This whorl sharks 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 squid and other small mollusk prey, but inflicting traumatic damage against more durable, faster prey. Their teeth grew at a much slower pace than that of other whorl-tooth sharks, resulting in a depreciated spiral, growing only half of the teeth a Helicoprion would grow in its life time. The tooth spiral also was able to indicate the age of the eugeneodontidans in question.