Probably through isolation, and adaptation to an unusually cool environment. No one can be entirely certain, of course, this question has no factual answer...we can only give opinions.
Yes
buttholes
buttholes
offshore newzealand.
They live in buts!
hatchlings
no
If you mean Tuataras, the native lizards, no one is certain how old they can get, but on an average around 80 years.
Tuataras
Therapsids
25,967
cold because it is a reptile