Temporal range: Lower Jurassic
|Wall-mounted skeleton of Temnodontosaurus platyodon, with puny humans reflected in the glass. Natural History Museum, London.|
Temnodontosaurus was an ichthyosaur from the early Jurassic, some 196 to 190 million years ago. It was found in England by Mary Anning, and later in Germany. It was, in fact, her first ichthyosaur. Her brother found the skull, and she found the rest of the skeleton, in about 1810. It was described in 1814. There are four or five species of Temnodontosaurus. They grew to killer whale size, about 30 to 40 feet.
This huge ichthyosaur cruised the shallow seas hunting. But hunting what? A discussion by Christopher McGowan suggests that other reptiles might have been on the menu. McGowan also mentions that in the museum collections are some teeth and bones which suggest even larger ichthyosaurs existed.
Ichthyosaurs hold the record for eye size: the largest was 264mm in diameter (~10.4 inches), from the species Temnodontosaurus platyodon. This is the largest eye ever recorded for any vertebrate; the colossal squid eye is larger still. The eyes are surrounded by sclerotic rings, a kind of bony support.