Dyopedids

Dyopedids are a group of extinct marine reptiles that belonged to the order Sauropterygia, closely related to plesiosaurs. They are notable for their elongated necks and streamlined bodies, which suggest they were highly adapted to aquatic life. The name "Dyopedids" is derived from the genus *Dyoplax*, one of the earliest known members of this clade, though the group was not formally named until later taxonomic revisions.

Fossil evidence of dyopedids primarily comes from the Late Triassic period, dating roughly between 220 and 200 million years ago. Their remains have been discovered in regions that were once part of the Tethys Ocean, including what is now Europe, Africa, and South America. The most well-studied dyopedid is *Dyoplax*, which possessed a long, flexible neck and a broad, flat skull, indicating a diet likely consisting of fish and other small marine creatures. Some researchers speculate that dyopedids may have been early ancestors of later, more diverse sauropterygians like plesiosaurs, though this remains a subject of ongoing debate.

Dyopedids were relatively small compared to later marine reptiles, with estimated lengths ranging from about 1 to 3 meters. Their skeletal structure, including the presence of a single occipital condyle (a feature shared with plesiosaurs), suggests they had a more specialized swimming posture, with their limbs positioned more horizontally than vertically. This adaptation likely improved their maneuverability in open water.

While dyopedids are not as widely recognized as other Triassic marine reptiles, such as ichthyosaurs or nothosaurs, their fossils provide valuable insights into the evolutionary transitions that led to the dominance of plesiosaurs in later Mesozoic seas. Further research into dyopedid anatomy and distribution continues to refine our understanding of their role in Triassic marine ecosystems.