Nothosaurus (Berlin Natural History Museum).


Nothosaurus (Greek for "false lizard"); pronounced NO-tho-SORE-us


Oceans worldwide

Historical Period:

Triassic (250-200 million years ago)

Size and Weight:

About 10 feet long and 150-200 pounds


Fish and crustaceans

Distinguishing Characteristics:

Long, tapered body; narrow head with numerous teeth; semi-aquatic lifestyle

About Nothosaurus

With its webbed front and back feet, flexible knees and ankles, and long neck and tapered body--not to mention its numerous teeth--Nothosaurus was a formidable marine reptile that prospered across the nearly 50 million years of the Triassic period. Because it bears a superficial resemblance to modern seals, paleontologists speculate that Nothosaurus may have spent at least some of its time on land; it's clear that this vertebrate breathed air, as evidenced by the two nostrils on the top end of its snout, and although it was undoubtedly a sleek swimmer, it wasn't as well adapted to a full-time aquatic lifestyle as later pliosaurs and plesiosaurs like Cryptoclidus and Elasmosaurus. (Nothosaurus is the best known of the family of marine reptiles known as nothosaurs; another well-attested genus is Lariosaurus.)

Although it's not widely known to the general public, Nothosaurus is one of the most important marine reptiles in the fossil record. There are over a dozen named species of this deep-sea predator, ranging from the type species (N. mirabilis, erected in 1834) to N. zhangi, erected in 2014, and it apparently had a worldwide distribution during the Triassic period, with fossil specimens discovered as far afield as western Europe, northern Africa and eastern Asia. There is also speculation that Nothosaurus, or a closely related genus of nothosaur, was the distant ancestor of the giant plesiosaurs Liopleurodon and Cryptoclidus, which were an order of magnitude bigger and more dangerous!