Class Reptilia
Turtles, Tortoises, Tuataras,
Crocodilians, Lizards, and Snakes
Classification
• Domain Eukarya
• Kingdom Animalia
• Phylum Chordata
– Subphylum Vertebrata
• Class Reptilia
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Order Chelonia
Order Crocodilia
Order Squamata
Order Rhynchocephalia
Order Chelonia
• Turtles and Tortoises
– Earliest fossils dated to 200 m.y.a
– Shell consists of fused boney plates
• Carapace (Dorsal, top)
• Plastron (Ventral, lower)
– 250 species worldwide
– Variety of habitats
• Most species ribs and
spine fused to inner
surface of carapace
• Pelvic and Pectoral
girdles lie within the
ribs
• Sharp beak instead of
teeth
• Shell and limbs reflect habitat
Turtles
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Marine or freshwater
Stream – lined shells
Webbing between toes
Terrapin refers to small aquatic or semi –
aquatic other than sea turtles
Tortoises
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Heavy domed shell
Retract limbs and head
Limbs sturdy with scales
Clubbed walking feet
Order Crocodilia
• Crocodiles, Alligators, Caimans, Gavial
Order Crocodilia
• Most closely related to dinosaurs
• Heavy bodied, mostly aquatic
• Carnivorous
Order Squamata
• Lizards and Snakes
– Upper jaw is loosely joined to the skull
– Jacobson’s organ
Lizards
• Only 2 species venomous
– Gila Monster
– Bearded Lizard
• Autotomy
Snakes
• Backbone of 100 – 400 vertebrates
– Pair of ribs attached to each vertebra
• Seize and swallow prey
• Constrictors
• Venom
– Fangs back of mouth
– Elapid, inject poison through fixed fangs in front
– Vipers, inject venom using large mobile fangs
Order Rhynchocephalia
• Ancient order inhabit few
small islands of New
Zealand
• 24 inches in length
• Spiny crest that runs down
the animal’s back
• Tolerate cool temp,
burrow during day and
hunt at night