Question

Describe (in essay format) the extant orders of reptiles and the reptile physiological systems that allowed them to complete the transition to land begun by the amphibians

Answer 1

Reptiles are tetrapod animals in the class Reptilia, comprising today's turtles, crocodilians, snakes, amphisbaenians, lizards, tuatara, and their extinct relatives. The study of these traditional reptile orders, historically combined with that of modern amphibians, is called herpetology.Class Reptilia

classification

• †Subclass Parareptilia
  • Order Pareiasauromorpha
• Subclass Eureptilia
  • Infraclass Diapsida
    • Order Younginiformes
    • Infraclass Neodiapsida
      • Order Testudinata (turtles)
      • Infraclass Lepidosauromorpha
        • Infrasubclass Unnamed
          • Infraclass Ichthyosauria
          • Order Thalattosauria
          • Superorder Lepidosauriformes
            • Order Rhynchocephalia (tuatara)
            • Order Squamata (lizards & snakes)
        • †Infrasubclass Sauropterygia
          • Order Placodontia
          • Order Eosauropterygia
          • Order Plesiosauri
          • Infraclass Archosauromorpha
          • Order Rhynchosauria
          • Order Protorosauria
          • Order Phytosauria
          • Division Archosauriformes
        • Subdivision Archosauria
        • Superorder Crocodylomorph
          • Order Crocodilia

Amphibians

• Includes frogs, toads, and salamanders
• Almost all are very much tied to the water for at least part of their lives.
• Almost all lay their eggs in water and pass through tadpole or larval stages with gills to an air-breathing adult stage, a process called metamorphosis.
• Most have delicate, thin skin and cannot survive far from water or moist woodlands.

Reptiles

• Include snakes, turtles, and lizards.
• First vertebrates to become truly independent of water.
• Eggs have a hard shell to prevent water loss, enabling reptiles to lay their eggs on land (including turtles and alligators).
• Scaly skin enables them to thrive even in the hot, dry climate of deserts.

Both reptiles and amphibians are poikilothermic, which means that they cannot regulate their own body temperatures internally as birds and mammals do. They do have behavior mechanisms, to warm up, such as basking on sunny days, and they survive our cold New England winters by hibernating in the relative warmth below ground or buried in the mud at the bottom of ponds.