Chondrichthyes Wiki
Register
Advertisement

Onchopristis is a genus of extinct giant sawfish that lived in the Lower Cretaceous to Upper Cretaceous in North Africa, North America and New Zealand. It had an elongated snout lined laterally with barbed teeth.

Description[]

Onchopristis is a large sawfish, known from remains throughout North America, North Africa and New Zealand. It was very large, up to 8 m (26.2 ft) long when fully grown. As with modern sawfish, Onchopristis's eyes were on top of its head, to spot predators rather than prey, and its mouth and gills were under its body. The rostrum, or snout, was around 2.5 m (8.2 ft) long, lined with barbed teeth. In the type species, O. numidus, each tooth had one barb, but in O. dunklei there were two to five barbs on each tooth, two to three in the subspecies O. d. praecursor, and three to five in the subspecies O. d. dunklei. The rostrum most likely would have had electrosensors to detect food in the water below them like most modern sharks and some rays. Onchopristis may have raked through the riverbed to find and then eat prey. An alternative hunting strategy might have been to strike prey with the barbed teeth of the rostrum; this may have more sufficiently wounded prey, allowing Onchopristis to swallow dead or wounded prey at leisure.

Predation[]

An Onchopristis tooth found embedded in the tooth socket of a partial skull of a Spinosaurus aegypticus, the largest known carnivorous dinosaur, suggests that Onchpristis was a prey item for the theropod. Such encounters might have been particularly common given the semiaquatic nature of this dinosaur.

Advertisement