Ichthyosaurus was small for an ichthyosaur. Some species, such as Shonisaurus and Shastasaurus, could grow up to 50 feet long, almost 5times as long as Ichthyosaurus.
Like modern dolphins, Ichthyosaurs had sleek bodies, triangular dorsal fins, paddle-shaped pectoral flippers, and long pointed beaks. However, their tails were vertically oriented like fish, rather than horizontal like a dolphin’s. Their resemblance to fish and whales is a result of convergent evolution, when two unrelated organisms develop similar traits to adapt to their environment.
Ichthyosaurs were reptiles, but they weren’t dinosaurs. They descended from reptiles that became amphibious (living on land and in water)and then fully aquatic during the Late Permian and Early Triassic Periods.
Ichthyosaurs were visual hunters, and had very large eyes.
LENGTH: 3.3 meters (11 feet)