First true land dwellersFirst true land dwellers Lay eggs on land- internal fertilizationLay eggs on land- internal fertilization –Amniotic egg covered with shell to protect from drying out (“land egg”)- rubbery –Have four embryonic membranes- amnion, yolk sac, allantois, corion

Strong bony skeleton and well developed lungs (2 lungs except snakes with 1)Strong bony skeleton and well developed lungs (2 lungs except snakes with 1) Most have 4 limbs (snakes have vestigial feet on pelvic bone called claspers)Most have 4 limbs (snakes have vestigial feet on pelvic bone called claspers) –More vertical under trunk than amphibians –Limbs larger, stronger, and more support more weight than amphibians

Modern dinosaur (?)Modern dinosaur (?) About 60 cm. longAbout 60 cm. long Only cool living reptile (50 deg.)- lives in New ZealandOnly cool living reptile (50 deg.)- lives in New Zealand Primitive body structure (very different from lizards)Primitive body structure (very different from lizards)

Plates (scutes) make up shell- 3 partsPlates (scutes) make up shell- 3 parts –Carapace (top), plastron (bottom) and hinge or bridge –Some can pull head and limbs in shell –Cannot leave shell- vertebrae attached

Well known for digestive problemsWell known for digestive problems Many dwindling due to human interactionMany dwindling due to human interaction

Alligator- broad head, round snout- teeth fit inside upper jaw Crocodile- triangular head, pointed snout- two protruding teeth

Lizards have legs, claws, external ears and movable eyelids (snakes do not)