Ichthyosaurs were marine reptiles that lived during the Mesozoic Era, around 250 to 90 million years ago. They resembled modern-day dolphins and were well-adapted to life in the ocean, with streamlined bodies and long snouts. These creatures were not dinosaurs but were part of a different group of reptiles that evolved to thrive in aquatic environments. These fascinating animals could grow quite large, with some species reaching lengths of over 20 feet. Ichthyosaurs primarily fed on fish and other marine animals, using their sharp teeth to catch prey. Fossils of ichthyosaurs have been found in many parts of the world, providing valuable insights into their biology and the ecosystems they inhabited.