Brothers Island tuatara
Sphenodon guntheri (Brothers Island tuatara) at the Southland Museum and Art Gallery, Invercargill, New Zealand.
DNA analysis on tuatara published in 2009 has shown that Sphenodon guntheri is best considered a distinct population of S. punctatus, but not a species.

Author: Nuytsia@Tas https://www.flickr.com/photos/nuytsia_pix/
Source: https://www.flickr.com/photos/nuytsia_pix/5709118233/

Tuatara are reptiles endemic to New Zealand. Although resembling most lizards, they are part of a distinct lineage, the order Rhynchocephalia. Sphenodon guntheri, or Brothers Island tuatara, is confined to North Brother Island in Cook Strait.
Order: Rhynchocephalia
Family: Sphenodontidae
Genus: Sphenodon
Species: Sphenodon guntheri Buller, 1877