Hybodus

Taxobox
name = "Hybodus"

---

image_caption = "Hybodus fraasi" in the Museum für Naturkunde in Berlin
fossil_range = Late Permian to Late Cretaceous
regnum = Animalia
phylum = Chordata
classis = Chondrichthyes
subclassis = Elasmobranchii
superfamilia = Hybodontoidea
familia = Hybodontidae
genus = "Hybodus"
genus_authority = Agassiz, 1837
subdivision_ranks = Species
subdivision = See text for species.

"Hybodus" ("humped tooth") is an extinct genus of once-common, widespread and long lived sharks, first appearing towards the end of the Permian period, and disappearing at the beginning of the Cretaceous (230-90 million years ago). During the Triassic, Jurassic, and Cretaceous periods the hybodonts were especially successful and could be found in shallow seas across the world. For reasons that are not fully understood, the hybodonts became extinct near the end of the Cretaceous period.

"Hybodus" species grew to about 2 m in length, and are believed to have been opportunist predators. It was not very big, but had the classic streamlined shark shape, complete with two dorsal fins that would have helped it steer with precision. The mouth was not large, and rather than ruthlessly hunt large prey, "Hybodus", was capable of eating a wide range of foods. They had several distinct features that made them stand apart from other primitive sharks: they had two different types of teeth (both sharp and flat), suggesting a wide diet (sharp for catching slippery prey, flat for crushing shelled creatures) , a bony blade on their dorsal fin for apparent protection, and the development of "claspers". These specialized organs aid males in reproduction by directly inserting sperm into the female. This last development has been passed on to modern sharks.

The first fossilized teeth from "Hybodus" were found in England around 1845. Since then teeth (and occasionally dorsal spines) have been recovered from around the world.

pecies

* "Hybodus houtienensis"
* ?"Hybodus butleri"
* ?"Hybodus obtusus"
* ?"Hybodus parvidens"
* ?"Hybodus rajkovichi"
* ?"Hybodus montanendis"

In popular culture

"Hybodus" was featured in the third episode of the popular 1999 documentary series "Walking with Dinosaurs", being attracted to the blood of an "Ophthalmosaurus" in labor. It was unidentified in this episode. "Hybodus" made its return in the 2003 spin-off "Sea Monsters", briefly shown feeding on a giant struggling "Leedsichthys" with "Metriorhynchus".

References

Haines, Tim, and Paul Chambers. The Complete Guide to Prehistoric Life. Pg. 89. Canada: Firefly Books Ltd., 2006.