platysomiforms

Platysomiforms are a group of extinct marine reptiles that lived during the Late Triassic and Early Jurassic periods, approximately 230 to 180 million years ago. They are characterized by their flat, broad bodies and long, narrow tails, which gave them their name, derived from the Greek words "platys" meaning broad, and "soma" meaning body. Platysomiforms are believed to have been semi-aquatic, with their bodies adapted for swimming and hunting in shallow marine environments.

The most well-known platysomiform is the ichthyosaur, a group of marine reptiles that evolved from platysomiforms. Ichthyosaurs are known for their streamlined bodies, powerful tails, and the ability to propel themselves through water using a unique swimming motion. Other platysomiforms include the plesiosaurs, which are also semi-aquatic reptiles known for their long necks and paddle-like limbs.

Platysomiforms are important in the study of marine reptile evolution, as they represent an early stage in the development of marine reptiles. Their flat bodies and long tails were likely adapted for swimming and hunting in shallow marine environments, while their semi-aquatic lifestyle allowed them to exploit new ecological niches. The study of platysomiforms has also provided insights into the evolution of marine ecosystems and the role of marine reptiles in ancient marine food webs.