Ichthyosaurus
Born tail-first into open water, as an Ichthyosaurus you would never set foot – or flipper – on land in your whole life.
A reptile that became a dolphin
Ichthyosaurus lived in the shallow seas that covered much of Europe in the Early Jurassic, roughly 200 to 190 million years ago. It was a marine reptile, not a dinosaur. Its ancestors left the land in the Early Triassic, and by the Jurassic ichthyosaurs had evolved a strikingly dolphin-like body: a streamlined torso, limbs turned into flippers, a dorsal fin and a crescent-shaped tail fin. Ichthyosaurus itself was no giant – adults were usually 1.5 to 3 metres long.
Big eyes and calamari
Large eyes, braced by a ring of bony plates, helped it hunt in dim water, and the long, narrow jaws carried rows of conical teeth for gripping slippery prey. Fossil stomach contents and coprolites (fossilised dung) from around Lyme Regis contain fish scales and the tiny arm hooks of belemnites, squid-like cephalopods. Your diet would be fish and ‘calamari’, swallowed whole.
As an air-breather you would surface regularly. Related ichthyosaurs even preserve traces of blubber and dark skin pigment – hints that they may have been warm-blooded.
Birth at sea
Ichthyosaurs could not crawl ashore to lay eggs. Fossil females with embryos inside, some caught in the act of giving birth, show that they had live young, often born tail-first like whale calves. You would have to swim from your first moment, and avoid larger ichthyosaurs and plesiosaurs.
The Anning connection
Ichthyosaurs were among the first fossil reptiles studied scientifically. In the early 1810s, Joseph and Mary Anning dug a large ichthyosaur skull and skeleton out of the crumbling cliffs of Lyme Regis in Dorset. Mary went on to become one of the most important fossil collectors of the 19th century, although as a working-class woman she received little credit in her lifetime.
