Reptiles Chapter 3 Section 4 K. Duff

Vocabulary Words Amniotic eggs Squamata Testudines Crocodilia Sphenodontia

Reptiles Inhabit every continent except Antarctica Classification: –Kingdom: Animalia –Phylum: Chordata –Class: Reptilia

Reptile Characteristics Ectotherms Scales –Thick, dry waterproof skin –Helps prevent waterloss –Prevents against injury Respiratory System –Breathe through lungs –Scales prevent breathing through the skin

Circulatory System –3 chambered heart with a partial wall (septum) Less mixing of CO 2 and O 2 blood –More advanced than amphibians Crocs and alligators have 4 chambered hearts

Reproduction –Internal fertilization –Amniotic eggs Tough leathery shell keeps them from drying out on land Complete environment for the embryo’s development Young reptiles look like small adults (no metamorphosis) Most provide little to no care for their young

Digestive System: –Can be omnivores, carnivores, and herbivores

Orders of Modern Reptiles 1.Squamata - Lizards and Snakes 2.Testudines -Turtles 3.Crocodilia - Crocodiles and Alligators 4.Sphenodontia - Tuataras

Squamata – Lizards & Snakes Lizards: Moveable eyelids External ears Legs with claws Some lizards can –Lose and re-grow their tails as a defense mechanism –Change color in response to stress

Snakes: No limbs Poor hearing and eyesight –Snakes “hear” vibrations from the ground through their jaw Carnivores –Jaw unhitches (increases mouth size) –Some constrict their prey (wrap around it) –Some inject their prey with poisonous venom

Elongated (stretched out) organs Use their Jacobson’s organ located on roof of mouth to follow trail of prey No eyelids – clean eyes with their tongues

Ways to Identify a Venomous Snake:

Testudines - Turtles The only reptile to have a two part shell made of hard bony plates The vertebrae, ribs, and muscles are attached to the shells These shells are used for protection against predators No teeth, mouth has powerful jaws and a beaklike structure used to crush food

What’s the difference between turtles and tortoises? Turtle = live on land and water Tortoise = lives only on land Aldabra Giant Tortoise Green Sea Turtle

Crocodilia- Crocodiles and Alligators Most advanced reptiles –4 chambered heart –Cerebral cortex (part of the brain that is used for memory, thought, and language) Large deep scales on their backs Powerful jaws with sharp teeth –They cannot open their mouths if their jaws are being held shut

Care for their young until they can protect themselves The eyes of a large alligator will glow red and those of a smaller one will glow green when a light is shined on them. –This fact can be used to find alligators in the dark.

Crocodiles vs. Alligators Crocodiles: –Narrow head, triangular shaped snout –Very aggressive –Greenish brown in color –Found all over the world Alligators: –Broad head, rounded snout –Less Aggressive –Blackish in color –Found only in SE USA and parts of China

Differences in Shape of Snout American Alligator Siamese Crocodile

Sphenodontia - Tuatara Called “living fossils” Only two species remain in their order Endangered since 1895 Only found in New Zealand Resemble lizards and can re-grow their tails, but they are different Beak-like jaw: 2 rows of bony teeth on top, 1 on bottom Hatchlings have a 3 rd “eye” that becomes covered with scales in adulthood

Parietal Eye Does not see images Photosensory organ –Sensitive to changes in light

The Importance of Reptiles Control pest populations (mice, snakes, rats) Their meat and eggs are used for food Skin is used for specialty items (wallets, boots, etc.)

Origin of Reptiles First appeared about 345 mya Hylonomus –Oldest-known reptile –8 to 12 inches (20 to 30 cm) long –Ate insects

Prehistoric Aquatic Reptiles: –Ichthyosaur –Champosaur –Mosasaur –Elamosaurus –Plesiosaur (the Loch Ness Monster is reported to be similar to this reptile)