iii) Reptiles-Dinosaurs

By: Camila Rodriguez

Dinosaurs

Not the first reptile

Triassic period

Cretaceous period

Diapsid skull

Reason for the name

From the Latin word 'reptilis'

Means 'creeping’

# of species currently existing 9,475 species

Divided in 4 groups: Crocodilia, Squamata, Testudines and Sphenodontia.

Crocodilia: alligators, crocodiles, caimans and gharials.

Squamata: Snakes and Lizards

Testudines: tortoises and turtles

Sphenodontia: tuataras

Crocodilia Squamata

Testudines Sphenodontia

Reptile characteristics Vertebrates=have backbone/internal skeleton

Cold blooded

Lay eggs on land (amniote eggs)

Get oxygen from lungs

Dry scaly skin

Hatch into young adults

3 chambered heart (alligators and crocodiles)

2 aortic blood vessels

4 or no legs

Internal fertilization

“Fossil record”

Oldest fossil 315 million years - Hylonomus (late Carboniferous period)

Life Cycle Some lay their eggs and some give live birth.

(oviparous) Some reptiles stay with their parents when born Grows becoming an adult Female fertilize internally producing the eggs They can reproduce more than once After giving birth they die Asexual reproduction

Life Expactancy Giant Tortoise: 152 years

Box Turtle 123 years

Alligator 68 years

Snapping Turtle 57 years

Cobra 28 years

Cottonmouth 21 years

Digestive System Very simple

Mouth

Salivary gland- softens and moistens food

Esophagus- a tube in which the food goes from the pharynx to the stomach

Intestine- from stomach to anus

Cloaca- outlet into the intestinal, urinary, and genital open

Eat

Most reptiles are carnivores feed on small invertebrates (mammals, reptile)

Some are herbivores feed on plant such as grasses, fruits, shrubs and marine plants.

Respiratory System Breath using lungs

Gas exchange in reptiles occurs in the alveoli ( diaphragm)

Breathing occurs in a change in the volume of the body cavity. Controlled by contraction of intercostal muscles.

Turtles and tortoise Ventilation of the lungs sheets of muscle in the shell that, through

contraction and relaxation, force air in and out of the lungs

Circulatory System Closed system

3 chambered hearts with two atria

Blood flows through heart

Mixing of oxygenated and deoxygenated blood

Sensory System They feel pain, temperature, pressure, and stretching at the dermal level. Crocodilia

Vertical cat-like pupil excellent diurnal / nocturnal vision External ears Eardrums Nostril

Squamata Eyelids- spectacle Smell with their tongue Ears

Testudines smell Ears: only hear vibrations and changes in water pressure Night vision

Sphenodontia

Great vision

Third eye

Weak taste buds

Sensory System

Bibliography

http://staff.tuhsd.k12.az.us/gfoster/standard/breptil.htm

http://animals.about.com/od/zoologybasics/a/howmanyspecies.htm

http://cowgirljess.hubpages.com/hub/The-Four-Groups-of-Reptiles

http://honorsbiologyp6.wikispaces.com/Reptiles+-+Sensory+Systems

http://www.exoticpetvet.net/reptile/rerepro.html

http://www.britannica.com/EBchecked/topic/498684/reptile/38474/Digestive-and-urogenital-systems

http://www.sandiegozoo.org/animalbytes/t-lizard.html