The Amazing Reptiles of the World

BY: CAMERON BERNARD, RYAN KIEWIT, & CAMERON FLORES

Class: Reptilia (Known for dry skin, epidermal scales, and respiration through the use of lungs)Order Testudines (Lack of teeth in adult form, instead they have modified beaks)Order Crocodylia (Elongated, full with muscles) Order Sphenodontida (Primitive lizards with well developed partial eyes)Order Squamata (Recognized by skull and jaw structures, most successful reptiles)

Reptile Classification

Examples: Turtles & TortoisesThere are approximately 300 different

species The bony shell, limbs articulating inward

towards the ribs, and the keratinized beak characterize turtles

The ventral portion of the shell is referred to as the plastron

The dorsal portion of the shell is referred to as the carapace which connects to the vertibrae, expanded ribs, and bones in the dermis of the skin

Order Testudines

Order Crocodylia

Examples: Crocodiles, Alligators, Gavials, ad Caimans Approximately 21 different species

They use their elongated snaps to capture its prey by utilizing swift sideways sweeps of the head

Nostrils at the end of the snout enables for the animal to breathe while submerged

Their muscularly elongated tail allows for swimming, offensive and defensive maneuvers, and attacking prey

Teeth are only necessary for seizing prey because they swallow their meals whole!

Crocodilians eat rocks and other sharp objects to aid in the food digestion process

Order Sphenodontida

Examples: Tuataras or lizard like reptiles Nearly 200 million years ago in the Mesozoic

era, tuataras became nearly extinct Two rows of teeth on the upper jaw enable

easy distinguishing among other reptiles An additional row of teeth on the bottom jaw

allows for easy chewing of animals such as birds

Tuataras are now only located in New Zealand and are protected by New Zealand law enforcement of preserved islands

Order Squamata

Examples: Snakes, Geckos, Iguanas, Chameleons, and Anolis

The order contains three suborders; Lizards, Snakes, and Worm Lizards

Lizards generally live on the substrates of rocks and retreat under rocks or logs if necessary

Lizards very in length from a few centimeters to 3 m

General Reptile Charactoristics Unlike the skin of amphibians, reptiles skin

has no respiratory function The skin is dry and thick and some scales

are modified for various functions All reptiles shed Blood flow does not extend to the epidermis

which allows for easy shedding of skin Reptile skulls have secondary palates which

separates the nasal passages from the oral cavity

Reptiles exhibit great flexibility

Nutrition and Digestion

Most reptiles are carnivorous, though turtles may be associated as herbivores, or omnivores as well

Snakes have adaptations in their skill necessary for feeding (The skull and jaw detach to allow digestion of food much larder than the snakes head)

Some lizards, anurans, and tuatara possess sticky tongues

Vipers utilize hollow teeth to inject their venom into their prey

Circulation

Circulation in reptiles is a lot like that of the amphibian circulatory system

Reptiles have two atria The ventral aorta and the conus arteriosus

divide during development in crocodiles The pulmonary artery leaves the ventral side

of the ventricle and takes blood to the lungs Reptiles can go “apnea” which is a period of

not breathing, turtles use this to conserve energy and permit more efficient oxygen usage

Gas Exchange

Reptiles utilize the ability to exchange gas across internal respiratory surfaces in order to avoid losing large amounts of water

Reptiles have a larynx but generally speaking vocal cords are absent

Lungs are sponge like interconnected chambers lines in cartilage

In many reptiles, a negative-pressure mechanist ventilates the lungs

Reptiles can regulate their body temperatures

Nervous System & Sensory Functions

The brain of a reptile is similar to that of other vertebrates in that the cerebral hemisphere is larger than that of amphibians

Reptiles possess binocular vision Many reptiles have upper and lower eyelids

that protect the surface of the eye Some reptiles even posses a median eye

(parietal eye) which are used to better differentiate light and dark orientations of the sun

Excretion and Osmoregulation Kidneys are used in order to filter blood

using nephrons Most reptiles excrete uric acid a

nontoxic soluble precipitate Many reptiles possess water and salt

glands that allow them to remove excess waste more easily

The bladder or the cloacal wall can reabsorb water and re use it in order to conserve in extreme climates

Reproduction

Some reptiles utilize internal fertilization by the means of using amniotic eggs (allows for eggs to be laid outside of water unlike that of amphibians)

In reproduction, males seek out females actively

Many reptiles display head-bobbing to portray their courtship towards the opposite sex

Reptiles produce pheromones to assess the reproductive potential of a mate

After eggs are laid, they are abandoned on the ground, under rocks, in debris, or in sand

Reptilian History

The archosaur depicts lineage of the reptilian species

Reptiles date back to 280 million years ago

Dinosaurs became the ancestors to reptiles

The pterosaurs were part bird, part reptile, and possessed to ability to fly

Many reptiles developed mammal-like characteristics in which were adapted in the Triassic and Carboniferous periods

!!Important Vocab!!

Amniotic Egg-The egg of reptiles, birds, and mammals, that allowed vertebrates to invade terrestrial habitats

Autonomy- Self amputation of an appendage for means of survival

Carapace-Dorsal shell of a turtle Jacobson’s Vomeronasal Organ- Organ used to sample

airborne chemicals Keratin- a tough water-resistant protein found in

epidermis of reptiles Median Eye- A photoreceptor located middorsally on the

head of reptiles Pit Organ- Plasteron- Secondary Plate-