Reptiles Daniel B. Ian F. Jesse O.. General Characteristics Dry skin with epidermal scales Skull with one point of articulation with the vertebral.

Reptiles

Daniel B.

Ian F.

Jesse O.

General Characteristics Dry skin with epidermal scales Skull with one point of articulation with

the vertebral column Lungs for respiration Metanephric kidneys Internal fertilization Amniotic eggs

Evolution and Relationships First vertebrates with amniotic eggs

(eggs with protective membranes and promote gas transfer)

Adaptive radiation of primitive amniotes gave way to the 3-4 lineages of reptiles.

Order Testudines TURTLES Bony shell and limbs articulating internally to the

ribs Teeth in adults replaced by a horny beak Has a shell consisting of a dorsal carapace

(forms from fusion of vertebrae, expanded ribs, and bones in the dermis of the skin) and ventral plastron

Oviparous Long life spans, live 14 or more years all the way

up to 100 years in some tortoises

Order Crocodylia Crocodiles, alligators, caimans, gaivals Elongate, muscular, and laterally compressed Triangular eye orbits rather than circular Tongue not protrusible (no :P) Complete ventricular septum Oviparous Food is swallowed whole so they swallow

rocks and other objects to break apart ingested food

Order Sphenodontida TUATARAS Only two species survive in New

Zealand Very primitive and lizard like Distinguished by tooth attachment and

structure

Order Squamata 3 Sub-orders

Sauria- Lizards Serpentes- Snakes Amphisbaenia- Worm lizards

Most structurally diverse reptiles Shed skin periodically Loosely attached jaws allows them to

open their mouths very wide

External Structure and Locomotion Skin is thick, dry, and keratinized (tough,

water-resistant protein found in the epidermal layers of the skin)

Periodically shed skin- called ecdysis Skin contains chromatophores for color

change Skeleton similar to amphibians yet can be

highly modified Many lizards are capable of autonomy (tail

loss adapted to escape from predators)

Nutrition and Digestion Most are carnivores, but turtles can be

herbivores, carnivores, or omnivores The upper and lower jaws in snakes can

move independently of eachother and the glottis allows the snake to breathe while swallowing its prey

Circulation, Gas exchange, Temperature Regulation The circulatory system is based on that

of amphibians 3 chambered heart Exchanging of gases across internal

respiratory surfaces to avoid losing large quantities of water

Most use external heat sources for thermoregulation and are ectotherms

Nervous And Sensory Have better sense of smell and more

reliance on vision than amphibians Rattlesnakes and other pit vipers have heat-

sensitive pit organs (lined with sensory epithelium and are used to detect objects with temperatures different from its surroundings)on each side of the face

Some reptiles have a median eye that is covered by skin and can differentiate light and dark periods

Excretion and Osmoregulation Reptiles require kidneys capable of

processing wastes with little water loss – metanephric kidneys of adults have more nephrons

Most reptiles excrete uric acid When water is available, many reptiles

store large quantities of water in lymphatic spaces or in the urinary bladder

Reproduction and Developement Internal fertilization All male reptiles, except tuataras, have

an intromittent organ for introducing sperm into the female

Eggs are usually abandoned after being laid

Only ~100 species have some degree of parental care of eggs

(Holds yolk)

Shell(protection)

Albumen(nutrients and protection)

VOCAB

amniotic eggs - eggs with protective membranes and promote gas transfer

autonomy - tail loss adapted to escape from predators

carapace - forms from fusion of vertebrae, expanded ribs, and bones in the dermis of the skin

keratin - tough, water-resistant protein found in the epidermal layers of the skin

pit organs - lined with sensory epithelium and are used to detect objects with temperatures different from its surroundings