Question

Give 4 points on the affinities of Sphenodon.

Answer 1

Hint: Reptiles are animals that belong to the Reptilia class, a paraphyletic grouping that includes all amniotes except synapsids and Aves. Tuatara was thought to be extinct on the mainland, with the remaining populations confined to 32 offshore islands until 2005, when the first North Island release into the heavily fenced and monitored Karori Wildlife Sanctuary (now known as "Zealandia") took place.

Complete answer:
Tuataras are endemic to New Zealand and belong to the Sphenodon genus. Despite their resemblance to most lizards, they belong to a separate lineage known as Rhynchocephalia. Their name comes from the Mori language, and it means "back peaks."
The tuatara (Sphenodon punctatus) is the only living member of its order, which dates back to the Triassic period around 250 million years ago and flourished during the Mesozoic period. The squamates are their most recent common ancestor with any other extant group (lizards and snakes).
Tuatara is therefore important in the study of lizard and snake evolution, as well as the reconstruction of the appearance and habits of the earliest diapsids, a group of amniote tetrapods that includes dinosaurs (including birds) and crocodilians.
The 4 points on the affinities of Sphenodon are as follows:
1. Sphenodon has a lizard-like body that is about 2 feet long, with a tail that is about 1/3 the length of the body. The Sphenodon is a nocturnal creature.
2. Sphenodon's body and tail are laterally compressed, with a series of spines dorsally present along the middle line.
3. Sphenodon's limbs are pentadactyl, and its legs are short and primitive. Around 10-11 carpels can be found on rare occasions.
4. The hind limbs of Sphenodon are usually plantigrade.

Note:
Lizards are cold-blooded, which means they rely on their surroundings to keep them warm. The scaly skin of a lizard does not grow thicker with age. Most lizards molt, or shed their skin, in large flakes. Lizards can also break off a portion of their tails if they are grabbed by a predator.