Groups of Reptiles

1. Groups of Reptiles

2. Groups of Reptiles • There are four groups of reptiles • Turtles and Tortoises • Crocodilians • Tuataras • Lizards and Snakes

3. Turtles and Tortoises • Have two characteristics that make them different from other reptiles • Have a hard shell that covers their body • A spine that is fused to the top of their shell • Most can pull their head and legs into the shell to avoid predators • Lay eggs in the ground but DO NOT care for their young • Lack teeth • Have jaws covered in hard plates • Many are herbivores • Some are carnivores (snapping turtle)

4. Turtles vs. Tortoises Turtles Tortoises Live on land Have a dome shaped shell • Live in water • Have a streamlined shell that allows rapid movement in water • The shell has two parts • Carapace = the top part of the shell • Plastron = the bottom part of the shell • Shell provides the support for all of the muscles attachments in the torso

5. Tuataras • Only two living species • Found in New Zealand • Look like lizards, but are a distinct group of ancient reptiles • Are called living fossils because they have survived nearly unchanged for a 150 million years • Are more active at low temperatures • Feed at night

6. Crocodilians • Includes crocodiles, alligators, caimans, and gavials • Crocodilians can grow to be very large

7. Crocodilian Feeding • Crocodilians are aggressive carnivores • Usually capture prey by ambush • Floats just under the water’s surface and waits for prey to drink from the water • The crocodilian explodes out of the water, seizes its prey and hauls it into the water to be drowned and eaten

8. Crocodilian Body Structure • Its body is well adapted to hunting • Its eyes are high on its head, and nostrils are located on top of its snout so it can see and breathe while nearly submerged in water • Have very sharp teeth to help them tear apart their prey

9. Crocodilian Reproduction • Unlike other reptiles crocodilians care for their young • Example: Alligators • Mothers build nest with vegetation to protect the eggs • Once the eggs hatch the mother tears apart the vegetation to free the hatchlings • They remain under the mothers protection for a year

10. Lizards and Snakes • Snakes are close relatives of lizards • Snakes and lizards have many features in common • Periodic molting • A jaw that is loosely attached to the skull • Allows mouth to open wide to accommodate large prey

11. Lizards • Common lizards are: Geckos, anoles, and horned lizards • Most lizards are carnivores • A few are herbivores • Lizards are typically found in tropical forests and deserts • Many are fast runners and good climbers • Are usually small (less than 30cm) • Have external ears and eyelids • Some are legless • They have a tail that can break off • Allows them to escape from predators

12. Snakes: Eating Habits • Snakes swallow their prey whole • A snake’s jaw is very flexible because the jaw has five points of movement • Some snakes are constrictors • They wrap their body around their prey and squeeze tighter and tighter until they suffocate their prey • Examples: Boa Constrictors, pythons • Other snakes kill their prey with venom • Modified salivary glands produce venom that is injected into the victim through their grooved or hallow teeth • Examples: Rattle Snakes, cobras, vipers

13. Snake: Reproduction • Most snakes lay eggs • Some mother snakes may stay with the eggs until they hatch • Some snakes are ovoviviparous and give birth to live young