Metriorhynchus is a metriorhynchid reptile from the Late Jurassic of the United Kingdom, France, Switzerland, and Germany. It was named in 1832 by Christian Erich Hermann von Meyer. It was a unique crocodylomorph, as it was heavily adapted to life in the ocean, even losing all its osteoderms in exchange for swift swimming.
Physiology[]
Despite being a crocodylomorph, Metriorhynchus had a build similar to that of ichthyosaurs and mosasaurids. It had a sleek, streamlined body, 4 flippers, a long tail with a shark-like fin on its end, and a long, conical head with a mouth filled with sharp, interlocking teeth. Its body would have been covered in scaly skin.
Diet[]
Metriorhynchus was a predator, preying on fish, cephalopods, and pterosaurs. Its sharp teeth were used for getting a hold of slippery prey, as well as tearing into their flesh.
Ecology[]
Like many marine reptiles, Metriorhynchus had anatomical features that allowed it to live life in the water, such as a slender, streamlined body, legs that evolved into flippers, and a large tail fin; in fact, it even devolved its osteoderms in order to not be weighed down while swimming. Of course, it is often debated whether Metriorhynchus was able to crawl onto land and lay eggs in a similar manner to a turtle; with a build so similar to the plesiosaurs and ichthyosaurs it lived with, it is unlikely that it would do so, being fully aquatic and giving birth to live young instead. Further evidence that Metriorhynchus had a seagoing lifestyle is the presence of salt glands; with salt glands removing excess salt from its blood, it would have been able to drink seawater and eat saltwater prey without dehydrating. A plesiosaur skeleton with tooth marks belonging to Metriorhynchus was found, and had reflected upon an explanation that the crocodylomorph had scavenged the plesiosaur's carcass; this shows that Metriorhynchus was capable of diving down to the seafloor in order to scavenge.
In popular culture[]
Metriorhynchus was featured in the 3rd episode of the 2003 documentary Chased by Sea Monsters, where it (along with a Hybodus) launches an attack on a weakened Leedsichthys (which was inaccurately oversized). Of course, this is artistic license, as the scenario of a 3 meter long crocodylomorph preying on a 9 (or 25, in the documentary's case) meter long bony fish would be quite unlikely.