Crocodilians

Crocodilians

• 1.
  Superorder: Archosaurs
• 2.
  Superorder: Archosaurs • agroup of diapsid reptiles that first evolved from Archosauriform ancestors . • They are represented today by birds and crocodiles. • are set apart by having socketed teeth • four-chambered hearts
• 3.
  CROCODILIANS
• 4.
  CROCODILIANS • From theMiddle Triassic • Include the subtropical and tropical alligators, crocodiles, caimans, and a single species of gavials. • They have survived major upheavals such as the break up of the continents and the ice ages.
• 5.
  Nile crocodile -Crocodylus niloticus Caiman - Caimaninae
• 6.
  Gharial - GavialisGangeticus American alligator - Alligator mississippiensis
• 7.
  Distinctive Features • powerfuljaws • protective scales • streamlined body • long tail • eyes and nostrils that are positioned on top of the head • elongated snout
• 8.
  Common Characteristics • Theyusually lay around in the water motionless. • Their eyes and snouts are the only part of their body that stays above the water. • Crocodilians have sharp teeth for capturing large prey. • semi-aquatic predators
• 9.
  Common Characteristics • Theyhave an extra transparent eyelid on each eye that can be closed to protect their eye when underwater. • They have a flap of skin at the back of their throat that prevents water from seeping in when they attack prey underwater. • They can also close their nostrils and ears in a similar manner to prevent the unwanted influx of water.
• 10.
  CROCODILIANS • Their featureshave changed very little from those of their prehistoric ancestors, proving that their body form has been highly successful in nature.
• 11.
  Crocodiles Alligators Gavial Caiman Shape Slender and Broad and long and slightly of triangular round narrow more snout pointed protrud on the hidden hidden ing lower jaw inside a inside a fourth socket on the socket on tooth upper jaw the upper jaw