Helicoprion
Helicoprion in LOST ZOO
Characteristic for the Buzz saw ratfish is the tooth whorl, reminiscent to a circular saw. How and where the tooth-whorl attached has been a question for scientists for almost 120 years.
In the beginning they placed the tooth-whorl not only within the mouth, but in different body parts, including the dorsal fin and the tail.
But most scientists placed the tooth-whorl in or near to the mouth, like a long, prehensile lash that could be swung amongst a shoal of fish, a hunting behavior similar to the sawfish. If a fish is injured by the tooth-whorl and becomes unable to swim, it can be eaten then. Later it was thought to have a tight tooth-whorl on the tip of a long jaw.
Today we know by CT scanning that the tight tooth-whorl is situated in a short lower jaw and will be used like circular saw to cut cuttlefish when they are eaten.
The various species of marine Buzz saw ratfish lived off the southwestern coast of Gondwana land. It first arose in the oceans 290 million years ago and eventually became extinct 250 million years ago. All the species of Buzz saw ratfish have a strange, but well working spirally arranged cluster of the individual’s teeth, the so called tooth-whorl, strongly reminiscent of a circular saw.
In the beginning scientists regarded the Helicoprion as a shark, but since a CT scanning in 2013 it is obvious now that indeed it is a rat fish and the chimaeras are the closest living relatives.
Body length: depending on the species in average 4-6 m, but some species also up to 10-12 m.
Diameter of tooth-whorl: 45-60 cm, 3 spirals with up to 180 teeth.
