History Turtles: the oldest living reptiles and have gone particularly unchanged in 200 million years. Turtles are considered to be the more intelligent of the reptiles. Lizards: make up the largest group of reptiles 3,000 worldwide.

History cont’d Snakes:

Unique Characteristics of Reptiles  indeterminate growth  scales cover the entire body  snakes shed their shin in one piece  when snakes shed their skin they “hide” from predators  legs- well developed-land travel  the characteristic that makes snakes unique is their loss of limbs  respiration-lungs-air breathing  eggs-calcareous-waterproof-laid on land  some snakes give birth to live young, examples are water snakes, garter snakes, ribbon snakes, pit vipers, etc… just to name a few  mating-on land mostly  female internal fertilization of the eggs  no larval stage-no transformation  Cold blooded

Medical importance The most common is the snake venom used as anti-venom In ancient Greece snakes were seen as healers

Snake rattle Snake hiss Timber rattlesnake: