Rhynchocephalia

The tuatara (, ; Sphenodon punctatus) is a species of reptile endemic to New Zealand. Despite its close resemblance to lizards, it is the only extant member of a distinct lineage, the previously highly diverse order Rhynchocephalia. The name is derived from the Māori language and means "peaks on the back".

Rhynchocephalia (; ) is an order of lizard-like reptiles that includes only one living species, the tuatara (Sphenodon punctatus) of New Zealand. Despite its current lack of diversity, during the Mesozoic rhynchocephalians were a speciose group with high morphological and ecological diversity. The oldest record of the group is dated to the Middle Triassic around 244 million years ago, and they had achieved global distribution by the Early Jurassic. Most rhynchocephalians belong to the suborder Sphenodontia ('wedge-teeth'). Their closest living relatives are lizards and snakes in the order Squa

Pleurosaurus, from Ancient Greek πλευρά (pleurá), meaning "rib" or "side", and σαυρος (sauros), meaning "lizard", is an extinct genus of aquatic reptiles belonging to the order Rhynchocephalia. Pleurosaurus fossils have primarily been discovered in the Solnhofen Limestone of Bavaria, Germany and the Canjuers lagerstatte near Canjuers, France, both dating to the Late Jurassic. It contains two species, P. goldfussi and P. ginsburgi.

Clevosaurus (meaning "Gloucester lizard") is an extinct genus of rhynchocephalian reptile from the Late Triassic and the Early Jurassic periods. Species of Clevosaurus were widespread across Pangaea, and have been found on all continents except Australia and Antarctica. Five species of Clevosaurus have been found in ancient fissure fill deposits in south-west England and Wales, alongside other sphenodontians, early mammals and dinosaurs. In regards to its Pangaean distribution, C. hadroprodon is the oldest record of a sphenodontian from Gondwana, though its affinity to Clevosaurus has been que

Homoeosaurus is an extinct genus of rhynchocephalian reptile, known from the Late Jurassic-earliest Cretaceous of Europe, with specimens being reported from France (Canjuers Lagerstatte), England (Purbeck Group) and Germany (Solnhofen Limestone). Several species have been described within the genus, based on varying proportions of the limb bones to the body length based on the presacral vertebrae. Specimen C.M.6438 of H. maximiliani from Germany has a total length of around , with a skull length of about . In comparison to other rhynchocephalians, the limbs are proportionally long. Recent stud

Priosphenodon is an extinct, large herbivorous eilenodontine rhynchocephalian known from the mid-Cretaceous (Albian-Turonian) of Argentina. It is one of the largest known sphenodontians.

Brachyrhinodon (meaning "short nose tooth") is an extinct genus of sphenodontian from the Late Triassic Lossiemouth Sandstone of Scotland.

Planocephalosaurus is an extinct genus of basal rhynchocephalian. Fossils of the genus are primarily known from fissure fill deposits from the Late Triassic of southwest Britain, with fragmentary remains possibly belonging to the genus also known from the Late Triassic of Texas.

left|thumb|Restoration of the skull in lateral and dorsal view Palaeopleurosaurus (meaning "old side lizard") is an extinct genus of diapsid reptiles belonging to the group Sphenodontia.

REDIRECT Rhynchocephalia

Opisthiamimus () is an extinct genus of small-bodied eusphenodontian rhynchocephalian from the Upper Jurassic Morrison Formation of Northern Wyoming, United States. The type species, O. gregori, is known from four specimens, which together preserve a nearly complete skeleton. It is amongst the smallest known rhynchocephalians, with a skull length of and a snout–vent length (the length from the tip of the snout to the cloaca) of around . The genus was described in 2022 by David DeMar, Marc E. H. Jones, and Matthew Carrano. It was found that it was only distantly related to Eilenodon, Theretairu

Vadasaurus is an extinct genus of rhynchocephalian closely related to the aquatic pleurosaurids. Although this genus was not as specialized as the eel-like pleurosaurs for aquatic life, various skeletal features support the idea that it had a semiaquatic lifestyle. The type species, Vadasaurus herzogi, was described and named in 2017. It was discovered in the Solnhofen Limestone in Germany, which is dated to the Late Jurassic. The generic name "Vadasaurus" is derived from "vadare", which is Latin for "to go" or "to walk forth", and "saurus", which means "lizard" (although rhynchocephalians are

Cynosphenodon ( ; "Dog Sphenodontian") is an extinct genus of rhynchocephalian in the family Sphenodontidae from the Middle Jurassic La Boca Formation of Tamaulipas, Mexico. It is known from a largely complete lower jaw and fragments of the upper jaw. It is suggested to be among the closest known relatives of the tuatara, with both being placed in the Sphenodontinae, which is supported by among other characters, the growth pattern of the teeth.

individual tuatara