Lepidosaurs - Tuatara + snakes & lizards

Lepidosaurs

Largest group of nonavian reptiles, includes tuatara, snakes, lizards.

Diapsids

Reptiles with two temporal fenestrae in skull.

Synapsids

Reptiles with one temporal fenestra in skull.

Sauropsids

Clade including reptiles and birds.

Transverse cloacal opening

Cloaca opening positioned horizontally, characteristic of Lepidosaurs

Ecdysis

Process of shedding old skin.

Acrodont teeth

Teeth not rooted, found in tuataras and many snakes.

Pleurodont teeth

Teeth in a single row, found in many lizards.

Thecodont teeth

Rooted teeth, characteristic of crocodiles and mammals.

Sphenodontids

Mesozoic group including the tuatara and Pleurosaurs.

Rhynochephalia

Order of reptiles that includes tuatara.

Sphenodon punctatus

Species name for tuatara, endemic to New Zealand, acrodont, heterodont, retains lower temporal bar in skull

Osteoderms

Bony deposits forming scales in some reptiles.

Parietal eye

Photo receptive structure, also known as the 'third eye'.

Order Squamata

Order encompassing lizards and snakes.

Determinant growth

Growth stops when structure fully formed (order squamata)

Kinetic skulls

Skull bones capable of movement beyond jaw (order squamata)

Hemipenes

Bifurcated copulatory organ in male squamates.

Jacobson's organ

Auxiliary olfactory organ for chemoreception.

Skull

Lightening of skull in reduction, both halves firmly united, lower temporal bar lost

Amphisbaenia

Suborder of worm lizards, mostly limbless.

Autarchoglossa

Suborder including skinks and monitor lizards.

Gekkota

Suborder of geckos, known for vocalizations.

Iguania

Suborder including iguanas and chameleons.