Nothosaurs - (pronounced NOTH-oh-sawrs)

Nothosaurs (order Nothosauria) were Triassic marine sauropterygian reptiles that may have lived like today's seals. It lived during the entire Triassic period.

 

Nothosaurs were long-necked, long-tailed, fish-eating reptiles ranging from a few inches to 20 feet (6 metres) long. Nothosaurs had four wide, paddle-like limbs with webbed fingers and toes which helped power the animal through the water when swimming. Their nostrils were on the top end of the snout. They breathed air but spent most of the time in the water. The forelimbs were shorter than the rear limbs.

Like Seals, they would catch food in the water but come ashore on rocks and beaches. They probably laid their eggs on land but hunted and ate in the sea. Nothosaurs ate fish and other small swimming animals like shrimp. They fished using their sharp teeth and long snout. Their neck was quite long and the head was elongate and flattened and relatively small in relation to the body. The margins of the long jaws were equipped with numerous sharp outward-pointing teeth.

The nothosaurs consist of two suborders - the Pachypleurosaurs, tiny, primitive forms, and the true Nothosaurs, which evolved from pachypleurosaurs. Nothosaur, like reptiles were in turn ancestral to the more completely marine plesiosaurs, which replaced them at the end of the Triassic period.

Fossils have been found in what is now Europe (Germany, Italy, the Netherlands, and Switzerland), North Africa, and Asia (China, Israel, and Russia).

Examples of Nothosaurs include:

Nothosaurus - as described above.

Lariosaurus - small, about 0.75-2 feet (20-60cm) long. It had a shorter neck and stubbier toes than other Nothosaurs. This must have limited its swimming ability. It had a streamlined body and a long, pointed tail. The back legs had five webbed toes with claws; its front legs were paddle-like flippers. It lived during the middle Triassic period. Fossils from the mid-Triassic period have been found in Europe.

Ceresiosaurus - about 13 feet (4 metres) long. It had longer toes than the other Nothosaurus, and more bones in each of the toes (hyperphalangy). This made the limbs very flipper-like, and Ceresiosaurus must have been a very good swimmer - almost like a plesiosaur. It lived during the mid-Triassic period. Fossils have been found in Europe.

Pistosaurus - about 10 feet (3 metres) long with a very long neck, four long, paddle-shaped flippers, a streamlined body, and many sharp, pointed teeth in long jaws. From Europe (France and Germany) during the mid-Triassic period.

Scientific Classification:

Kingdom: Animalia

Phylum: Chordata

Class: Sauropsida

Superorder: Sauropterygia

Order: Nothosauria