Cretoxyrhina (Extinct)

A prehistoric thresher?

Cretoxyrhina is an extinct genus of large mackerel shark that lived from the Late Albian to Early Maastrichtian during the Late Cretaceous period 100 to 80 million years ago. It is estimated up to 23 to 26 feet in length.  The common name is the Ginsu shark, because of its theoretical feeding methods being comparable to that of a modern Ginsu knife. Research suggests it was built for great bursts of speed and demolishing prey. It was thought to be a great predator.

Family: †Cretoxyrhinidae


Genus: †Cretoxyrhina

Species: †mantelli



Phylum– Chordata

Class– Chondrichthyles



Common Name– Mackerel

Family– †Cretoxyrhinidae

Common Name– Ginsu shark (named after the Ginsu knife for its razor sharp teeth)

Genus– †Cretoxyrhina

Species– †mantelli

Status: EXTINCT. Cretoxyrhina lived from the Late Albian to Campanian during the Late Cretaceous period, 100-80 million years ago.

Cretoxyrhina was first identified by the famous Swiss Naturalist Louis Agassiz, in 1843, as Cretoxyhrina mantelli. The most complete specimen of this shark was discovered in 1890, by fossil hunter Charles H. Sternberg, who published his findings in 1907.

Average Size and Length: Fossils suggest that Cretoxyrhina had a length of up to 23-26 feet.

Average Weight: 1,000-2,000 pounds

Teeth and Jaw: The teeth of Cretoxyhrina were up to 3 inches long, curved, and smooth-edged, with a thick enamel coating. The jaws of Cretoxyrhina contained up to seven rows of teeth, with 34 teeth in each row of its upper jaw and 36 in each row of its lower jaw.

Head: Cretoxyhrina had a conical head with a blunt snout and large eyes.

Tail: Some Research suggests a lunate tail.

Demographic, Distribution, Habitat, Environment and Range: Cretoxyrhina fossils are cosmopolitan and have been found world-wide, being most frequent in the Western Interior Seaway area of North America.

Diet: Cretoxyrhina was among the chief predators of the seas. Fossil records revealed that it preyed on a variety of marine animals, such as mosasaurs like Tylosaurus, plesiosaurs like Elasmosaurus, giant bony fish like Xiphactinus, and protostegid turtles like Archelon. Research suggests that on occasion Cretoxyrhina fed on a Pteranodon, as a bone from the latter has been discovered with the shark’s tooth embedded in it.

Ram-Suction Index: Cretoxyrhina used force because bite marks and teeth embedded in the bones of its prey are well preserved.

Aesthetic Identification: Cretoxyrhina was a very large shark, and had a fusiform body, looked very similar to a Great White shark based on fossil records.

Some scientists suggest that Cretoxyrhina belonged to the Threshers, and could look more similar to one, yet this research is too early in its stages and Cretoxyrhina remains in the current family.

Biology and Reproduction: Cretoxyrhina was the largest shark during its time. Cretoxyrhina is among the most well-understood fossil sharks to date, with several preserved specimens having revealed a great deal of insight about its physical features and lifestyle. In terms of morphological features including body size and shape, skeletal anatomy, and ecological role, Cretoxyrhina is most similar to the modern Great White shark. However, the two sharks are not closely related, and their similarities are a result of convergent evolution.

Speed:  Research suggests Cretoxyrhina was built for great speeds and distances. Research suggests Cretoxyrhina was capable of bursts up to 43 miles per hour.