Segadus

Segadus is a lesser-known genus of small, extinct marine reptiles that lived during the Late Cretaceous period, approximately 90 to 66 million years ago. Fossil remains of Segadus have been discovered primarily in the Western Interior Seaway of North America, particularly in the states of Kansas and Colorado. The name *Segadus* derives from the Latin word *segadus*, meaning "little fish," reflecting its small size relative to other contemporaneous marine reptiles.

Segadus is classified within the family Elasmosauridae, a group of long-necked plesiosaurs. Fossil evidence suggests that it was a relatively small elasmosaurid, with an estimated total length of around 3 to 4 meters (10 to 13 feet). Its skull was narrow and elongated, equipped with sharp teeth adapted for catching fish, its primary prey. The vertebral structure of Segadus indicates a long, flexible neck, which likely aided in capturing prey in the open water.

Like other elasmosaurids, Segadus possessed a streamlined body, four flippers for propulsion, and a tail adapted for swimming. Its small size may have allowed it to exploit ecological niches not occupied by larger marine reptiles, such as feeding on smaller fish or squid in shallow coastal waters. The discovery of Segadus fossils provides valuable insights into the diversity and adaptation of marine reptiles during the Late Cretaceous, a time when the Western Interior Seaway was a vast, inland seaway teeming with life.

Fossil specimens of Segadus are housed in museums such as the Sternberg Museum of Natural History in Hays, Kansas, and the Denver Museum of Nature & Science. Research on this genus continues to contribute to our understanding of the evolutionary history and ecological roles of elasmosaurid plesiosaurs.