|1st Species||Hybodus houtienensis|
|Time Range||260-66 mya|
|Name Meaning||Humped tooth|
|Physical Dimensions||2 meters long|
Hybodus is a hybodontid hybodontiform cartilaginous fish from the Guadalupian-Late Cretaceous of the entire world. It was named in 1837 by Louis Agassiz. It was the most successful shark of all time, even happening to be a notable disaster taxon.
Hybodus was a unique shark. It was a cartilaginous fish with a torpedo-shaped body, triangular pectoral and dorsal fins, a crescent-shaped caudal fin, and a mid-sized head with a blunt nose and mid-sized jaws; however, its dorsal fins had spines attached to them, and its tail looked more like that of a placoderm than that of a modern shark. Its body would have been covered in scaly skin.
Hybodus was a predator, preying on small fish, cephalopods, crustaceans, and bivalves. Its jaws had two kinds of teeth; at the front of its jaws, it had sharp, pointed teeth designed for grabbing prey, while at the back of its jaws, it had more rounded teeth designed for crushing shells.
Hybodus's main key features were its dorsal fins; it is speculated that the spines attached to them were used to stop predators like Liopleurodon or Dakosaurus from effortlessly ripping the shark into pieces, while it is certain that the fins themselves helped the shark steer itself. Along with this, it was a successful predator with a wide diet, as its two teeth were very useful for eating; its sharper front teeth were used for grabbing soft-bodied prey, while its rounded back teeth were used for penetrating the defenses of hard-shelled bottom-dwellers. So far, the only animals that weren't on its list were animals too big to fit in its mouth; this included large fish such as Leedsichthys, as well as large marine reptiles such as Ophthalmosaurus and Cryptoclidus. Along with this, unlike other sharks, which had completely smooth cartilaginous skeletons, Hybodus had a hard, bone-like cartilaginous skeleton; this has helped scientists find out its physiology.
In popular cultureEdit
Hybodus was featured in the 3rd episode of the 1999 documentary Walking with Dinosaurs, where it is shown as an ancient and long-lived predator that still could fall prey to larger predators like (an inaccurately oversized) Liopleurodon; as well as this, it was depicted as being able to eat baby Ophthalmosaurus. It appeared again in a similar documentary, Chased by Sea Monsters, where it (alongside a Metriorhynchus) launches an attack on a dying Leedsichthys (also oversized); however, this is artistic license, as it couldn't eat anything that was bigger than its mouth.