|1st Species||Temnodontosaurus platyodon|
|2nd Species||Temnodontosaurus eurycephalus|
|3rd Species||Temnodontosaurus nuertingensis|
|4th Species||Temnodontosaurus trigonodon|
|Time Range||198-174 mya|
|Location||United Kingdom, Germany, France|
|Name Meaning||Cutting-tooth reptile|
|Physical Dimensions||7.5 meters long for T.platyodon; 6 meters long for T.eurycephalus; 9.2 meters long for T.trigonodon|
Temnodontosaurus resembled the generic ichthyosaur. It had a sleek, streamlined body, 4 flippers, a long tail with a shark-like fin on its end, a large fin on its back, and a conical head with large jaws. Its body would have been covered in scaly skin.
Temnodontosaurus was a predator, preying on fish, cephalopods, and smaller marine reptiles. In one Temnodontosaurus species, Temnodontosaurus eurycephalus, the teeth were sturdy and robust (heavily built), and were used for crushing large prey, while in other Temnodontosaurus species, the teeth were thin and pointy, and were used for catching slippery fish (although species like Temnodontosaurus trigonodon were not above going after the occasional smaller ichthyosaur); in fact, one Temnodontosaurus species, Temnodontosaurus azerguensis, had no teeth at all.
Due to its streamlined body, Temnodontosaurus was a fast swimmer, often propelling itself through the water using its finned tail (like other ichthyosaurs), as well as using its smaller pectoral fins for steering. Like other marine reptiles, it lived in the open ocean; however, unlike them, it never went near the coast. As well as this, like most other ichthyosaurs, it gave birth to live young, with pups being delivered tail-first in order to prevent any risk of drowning. Most Temnodontosaurus species preferred to snag fish, squid, and belemnites with their pointy teeth, seldom going after larger prey; however, one species of Temnodontosaurus, the aforementioned T.eurycephalus, went after tougher prey such as ammonites and even marine reptiles such as Ichthyosaurus and Plesiosaurus, using its large, heavily-built teeth to crush them and tear them to pieces.