Reptilia – “creepy crawly”

• Examples: snakes, lizards, crocodiles, turtles

Traits

• Dry, scaly skin

Traits

• ectotherms

Traits

• Well developed lungs

Traits

• 3 chambered heart with partially divided ventricle

Traits

• Muscular bony legs to the sides, if any at all

Traits

• Toes with claws

Traits

• Internal fertilization

Traits

• Lay amniotic eggs on land

Reptile egg

Amphibian egg

Reptilian heart

• Good pressure, partially divided ventricle keeps blood from mixing as much

Reptilian adaptations for land life

• To avoid dehydration – waterproof skin, colon absorbs water from feces, low respiration rate loses less water

• Reproduction – internal fertilization, amniotic egg

Copulation

• Process of internal fertilization, male inserts sperm into the female system

Amniotic egg

• Overcame the last obstacle to life on land

Amnion

• provides a water environment for the developing embryo

amnionembryo

Albumen

• Provides protein for building materials (white)

embryo

albumen

Yolk sac

• Provides food energy

embryo

yolk sac

Shell and Chorion

• Protects and waterproofs

embryo

shell

chorion

Allantois

• Collects wastes, acts as a respiratory surface

embryo

allantoise

Orders of Reptiles

Squamata Testudinata

Crocodilia Rhynchocephalia

Squamata

• Largest order of reptiles

• E.g. – snakes and lizards

Testudinata

• Turtles and tortoises

How do you tell them apart?

Turtles

• live mostly in water, flatter shell, fast

Tortoises

• live on land, rounded shell, slow

Turtle or Tortoise?

Turtle or Tortoise?

Crocodilia

• Crocodiles and alligators

Alligators• broad head • rounded snout • teeth not as visible on

bottom

Crocodiles• narrow head • pointed snout • teeth visible on top and bottom

Alligator or Crocodile?

Alligator or Crocodile?

Alligator or Crocodile?

Alligator or Crocodile?

Rhynchocephalia

• Tuatara

3 rows of teeth (2 on top and 1 on bottom) and a light sensitive gland on its forehead that looks like a third eye