File:Ichthyosaurus communis (fossil ichthyosaur) (Lower Jurassic; Lyme Regis, England) 1 (34978157203).jpg

Ichthyosaurus communis De la Beche & Conybeare, 1821 - fossil ichthyosaur skull from the Jurassic of Britain. (CM 877, Carnegie Museum of Natural History, Pittsburgh, Pennsylvania, USA)

Ichthyosaurs are an extinct group of large, predatory, marine reptiles. They had a fusiform body similar in gross morphology to modern dolphins and porpoises. The latter are mammals, while ichthyosaurs were reptiles. The evolution of similar body plans in unrelated organisms is called convergent evolution. Ichthyosaurs and dolphins are the most commonly cited examples of this evolutionary process.

Ichthyosaur fossils are only found in Mesozoic sedimentary rocks - they first appear in the Triassic and go extinct in the Cretaceous.

From museum signage: The Jurassic was the heyday of the ichthyosaurs, air-breathing reptiles that were superbly adapted for life at sea. With their toothy jaws, streamlined bodies, and powerful flippers and tails, Jurassic ichthyosaurs bore a strong resemblance to modern fast-swimming fishes and dolphins. Most were high-speed pursuit predators of invertebrates, fishes, and other marine reptiles.

Ichthyosaurus was a typical Early Jurassic ichthyosaur that grew up to 7 feet long. It ate fishes and squid-like cephalopods, snatching them up with its long jaws and swallowing them whole.

Classification: Animalia, Chordata, Vertebrata, Reptilia, Ichthyosauria, Ichthyosauridae

Stratigraphy: unrecorded/undisclosed Lower Jurassic unit

Locality: unrecorded/undisclosed site (but apparently at or near Lyme Regis, southern Cornwall Peninsula, southwestern England)

See info. at: <a href="https://en.wikipedia.org/wiki/Ichthyosaurus" rel="nofollow">en.wikipedia.org/wiki/Ichthyosaurus</a> and