"The tuatara is a reptile native to New Zealand. You might look at it and think it’s a lizard like so many others, but in fact, it is a very unusual branch of the reptile tree and is not closely related to any extant lizards or snakes. In fact, it’s not a lizard at all; it’s a very primitive reptile that shares almost as many traits with birds as it does with lizards, which makes it of great interest to evolutionary biologists.
"The tuatara is unusual for lots of reasons; it has a single-chambered lung, the most primitive heart of any reptile, its teeth are not teeth but rather jagged outcroppings of its jawbone, its spine resembles that of a fish more than any other reptile, and, oh, wait, it has three eyes. Yes. Three eyes. And its lifespan is just as weird; it reaches sexual maturity extremely late, at between 20 and 30 years, and doesn’t even stop growing until its 35th year. That means the tuatara is also extremely long-lived, frequently breaking the century mark. A tuatara named Henry became a father at age 111, back in 2009, and some experts believe the tuatara could reach 200 years in captivity.”
(A reptile with a 3rd eye, at an evolutionary point millions of years behind modern lizards. Interesting. -RS)