THE TUATARA {too-uh-tar'-uh}A lizardlike reptile that is found only on a few islands near New Zealand, the tuatara is the only living member of an otherwise extinct reptilian order, Rhynchocephalia, that is said to have flourished in the Triassic and Jurassic period. They have been called "living fossils" since they appear identical to specimens in the fossil record, and even resembles the lizard-like Glevosaurus. Yet there are no tuatara specimens in more recent layers of the fossil record. Tuataras grow to 80 cm (31 in) in length and have scaly brown-green skin and a crest of dinosaur-like spines along their back. Some tuataras have been known to live for over 100 years! Tuataras are mostly nocturnal. Their diet consists largely of insects and the occasional small animal. They are anatomically different from lizards and easily distinguished by an extra arch in their skull. Could tuataras really have remained virtually unchanged for hundreds of millions of years while catastrophic environmental changes wiped out dinosaurs and while descendants of rodent-sized mammals slowly evolved into humans?