By: Nirali Kalaria Lauren Tragesser

1. Reptiles By: Nirali Kalaria Lauren Tragesser

2. Reptiles Turtles Lizards Alligators Crocodiles Snakes Tortoise

3. Characteristics • Dry, scaly skin • 3 chambered heart • Lay amniotic eggs on land (hard shelled) • Breathe through lungs • Ectotherms (cold blooded) • Tetrapods (4 limbs)

4. Outer Structures • Have scales that contain the protein keratin • Scales help protect the skin from desiccation and abrasion • Toes have claws • Two hind legs and two fore legs (except snakes) • Snakes don’t have moveable eyelids but have transparent caps (brille) for eye protection • Turtles and tortoise have a carapace (shell)

5. Locomotion • Legs are projected outward from the body • The larger reptiles walk very slowly • Smaller lizards can run fast (basilisk lizard can run across water) • Snakes do not have legs, so they slither, twisting and bending their bodies (serpentine locomotion) • Turtles, alligators, and crocodiles can swim • Alligators and crocodiles use their strong, long tails for steering • Turtles have wide feet that help them swim

6. Feeding/Digestion • Most reptiles are carnivores, but few are omnivores and herbivores • Carnivores swallow the prey whole • They only use their teeth to hold the prey • Poisonous snakes use their venom and fangs to kill prey • Reptiles eat mice, birds, plants, small mammals, amphibians, fish, invertebrates, eggs, and even other reptiles • Predators hunt by ambushing and foraging • Snakes and lizards are preyed on by large birds and other reptiles

7. Respiration • All reptiles breathe through lungs • They breathe by the means of muscles between the ribs and stomach muscles because they do not have a diaphragm • In snakes, the right lung is larger and the left lung is very small or absent • Reptiles inhale oxygen and the excretion of CO2 is performed by two small kidneys • Excrete waste through the anus

8. Circulation • Ectothermic- absorb external heat as their main source of body heat • Most have 3 chambered hearts BUT some, like crocodiles have 4 and others, like pythons and monitor lizards have 3 chambered hearts that become four chambered hearts because of a ridge that completely separates the ventricle during systole. • The heart consists of two atria and a ventricle, along with two aorta • In certain conditions, blood can be shut into different areas, oxygenated blood back into lungs and deoxygenated blood back to the body.

9. Circulation

10. Nervous And Control • Same basics as the amphibian brain, but the cerebrum and cerebellum of reptiles are larger • Most sense organs well developed • Exception: snakes external ears, they only have middle and inner ears • 12 cranial nerves • Brains are smaller than mammals in comparison to size relative to their bodies • Not considered intelligent organisms • Jacobson’s organ- an organ for detecting odor, located in the roof of their mouth.

11. Excretion / Waste • Performed by two kidneys • Diapsids- uric acid is the main nitrogenous waste product, in turtles urea is mainly excreted • Use colon to aid in reabsorption of water • Excess salts excreted by nasal and lingual glands in some Picture of a diapsid skull 

12. Reproduction • Internal fertilization- fusion of eggs and sperm in the female reproductive tract • Lay eggs • Amniote egg- shelled egg in which the embryo develops within the fluid filled amniotic sac, nourished by the yolk • Oviparous- young hatch from eggs outside mothers body • Ovoviviparous- young hatch from eggs retained inside mothers body

13. FunFacts • Reptiles inhabit every continent except Antarctica • There are 8,240 species of reptiles • Some turtles can live for over a century • Plastron- the part of a turtle’s shell that forms the underside • Neurotoxin- any toxin that affects neural tissues, ex. Some venoms • Hemotoxin- any toxin that destroys red blood cells and disrupts blood clotting • Endotherm- maintain body temperature through metabolic activity • Depending on the size of the meal, anacondas can go for months between meals • flicking the tongue is used as a smelling device