Michael Booth

First appeared in the late Cretaceous (84 mya) Worldwide 3 families 8 genera 23 species

Teeth can be replaced one after another but will slow with age Dermal Pressure Receptors can detect slightest disturbances on surface of water allows them to detect prey, danger, and intruders even in total darkness.

Skin is comprised of non-overlapping scales that are shed individually Small plates of bone called osteoderms have annual growth rings and can be counted to approximate age A secondary bony plat enables them to breath while partially submerged even if mouth is full of water Gender is not controlled by genetics but rather incubation temperature.

Crocodilians are generally found in tropical regions

2 out of the 23 species are native to North America Alligator mississippiensis (American Alligator) Crocodylus acutus (American Crocodile) Located mainly in the southeastern states

Alligator mississippiensis (American Alligator) Crocodylus acutus (American Crocodile)

Australian freshwater crocodile (Crocodylus johnstoni ) Black caiman (Melanosuchus niger )