Do any collections hold this subspecies? I do know that the Northerns are kept, but this subspecies seems unrepresented. Any images of this species? It does seem that the Cook Strait ones look a bit more crocodilian in the head shape, while the Northerns look a bit, well, more Tuatara-ish?
Isn't there a Sphenodon guntheri species, along with a species Sphenodon punctatus with subspecies punctatus and the Cook Strait subspecies?
No, Sphenodon guntheri and Sphenodon punctatus were lumped in 2009 to form two subspecies of a single species, Sphenodon punctatus.
Nice to know. I was skeptical, as since man sources stated only one species, though there were reports of a second. S. p. punctatus is the Northern subspecies, with S.p. guntheri being the Cook Strait?
Not quite; punctatus is indeed the Northern, but also covers the Cook Strait populations outside the Brothers Islands.
As I already said, the Cook Island populations (barring those on Brothers) are punctatus, and the Brothers population is guntheri.
Oh! I understand (?)! Cook Island and Northern Subspecies were lumped into one subspecies, whilst Brothers is guntheri! If punctatus it seems, is identified throughout the zoo world, where can I find guntheri?
There are no guntheri on-display anywhere to my knowledge; as noted upthread San Diego has an offshow group, and I think a few breeding centres in NZ hold the taxon too. As for your other point, you're the only person I've ever heard refer to the Cook Island population as a distinct (but judging by the fact you haven't given any name for it, undescribed) subspecies.
All my reading has just shown "unnamed" subspecies, which made me a bit skeptical, so I still went with it because I thought it was a new thing no one has came up with a name for.
All the Common Tuatara outside New Zealand are from Cook Strait (not the Cook Islands, which are an island group in the tropics). The only Brothers Island Tuatara outside NZ are at San Diego.
I think the Tuatarium at the Invercargill Museum still has them on display but I haven't been there for a while. Otherwise they are kept at Victoria University where wild eggs were being hatched out for head-starting populations on other islands. Tuatara are managed as three distinct populations, but they are all one species (as currently recognised). You have the northern population (the subspecies punctatus) from the islands around the northern part of the North Island; you have the western Cook Strait population (this is the one typically treated as an unnamed subspecies); and you have the North Brother population (guntheri). The Cook Strait animals, including the Brother Islands Tuatara, are all more closely related to one another than they are to the northern punctatus. Although overseas zoos all call their animals "Northern Tuatara S. p. punctatus" they are all of Stephens Island descent (i.e. Cook Strait animals). Here's a photo of a Brother Islands Tuatara I took years ago:
Yeah I don't know if all the animals are this colour, but all the ones I've seen have been. However, having said that, regular Tuatara come in a range of colours too including greenish and reddish.
Well they're only on islands, except for some "mainland islands" (i.e. predator-proofed fenced areas like Zealandia in Wellington city). On the islands which are public access they are easy enough to see.