seiasts

Seiasts are a group of extinct marine reptiles that lived during the Late Triassic period, approximately 230 to 200 million years ago. They are characterized by their long, slender bodies, paddle-like limbs, and a long, whip-like tail. Seiasts are believed to have been semi-aquatic, spending much of their time in or near water. Their diet is thought to have consisted primarily of fish and other small aquatic animals.

Seiasts are named after the genus Seiastes, which was first described by the German paleontologist Friedrich von Huene in 1929. The name Seiastes is derived from the Greek words "seia" meaning "dry" and "astes" meaning "foot," reflecting the semi-aquatic nature of these reptiles.

There are several species of seiasts, including Seiastes longiceps, Seiastes longirostris, and Seiastes longicollum. Seiasts are considered to be part of the larger group of marine reptiles known as ichthyosaurs, which also includes the more famous Plesiosaurus. However, seiasts are distinct from ichthyosaurs in their body shape and limb structure.

The fossil record of seiasts is relatively limited, with most specimens being found in Europe and North America. Despite this, seiasts are an important part of our understanding of the evolution of marine reptiles and the transition from land to sea.