Rytiodus is an extinct genus of sirenian, whose fossils have been discovered in Europe.

Description

With a length of 6 m (20 ft), Rytiodus was about twice the size as modern sirenians, surpassed only by Steller's sea cow

Steller's Sea Cow

Steller's sea cow was a large herbivorous marine mammal. In historical times, it was the largest member of the order Sirenia, which includes its closest living relative, the dugong , and the manatees...

, which was up to 8 m (27 ft) long. Like its closest modern relatives, the dugong

Dugong

The dugong is a large marine mammal which, together with the manatees, is one of four living species of the order Sirenia. It is the only living representative of the once-diverse family Dugongidae; its closest modern relative, Steller's sea cow , was hunted to extinction in the 18th century...

s, Rytiodus had a pair of flippers, a streamlined body and a tail fin. Its flattened snout allowed it to feed in shallow coastal waters. Unlike modern sirenians, Rytiodus had short tusks which it may have used to extract food from the sand.