Ichthyosaurs were a group of reptiles that lived millions of years ago and were adapted to life in the seas. They were characterized by their streamlined bodies, long snouts, and sharp teeth. There are several synonyms for ichthyosaurs, including fish-lizards, sea dragons, sea serpents, and marine reptiles. These names reflect the various physical features of these creatures, including their appearance and their habitat. Despite being extinct for millions of years, ichthyosaurs continue to fascinate scientists and the public alike, and their fossils provide valuable insight into the evolution of marine reptiles and the oceans in which they lived.