Great Plains Skink 36-I
SAUROPSIDA
"Reptiles"
 
 
Great Plains Skink (Eumeces obsoletus)



Chapter Outline
  1. Description of Sauropsida
  2. Classification of Sauropsida
  3. Sphenodontia
  4. Squamata
  5. Serpentes
  6. Testudines
  7. Crocodylia
  8. Paleo Sauropsida

Tree
NCBI Tree | Paleo Tree



Links to external sites will appear in pop-up windows.		  
Tetrapods are split between the amphibians and the amniotes. Amphibians need to lay their eggs in water because their eggs are "naked", not protected by a membrane that keeps them from drying out. Amniotes do have a protective membrane, called an amnion. In reptiles, birds and a few species of mammals, the amnion is surrounded by a shell, so the eggs are not dependent upon water to keep from drying out. In most mammals, the embryo is enveloped in an amnion which develops within the parent's body.

Amniotes are further split into the groups Sauropsida and Synapsida. The only group of synapsids in existence today is Mammalia. Mammalia will be the focus of chapter 38.

The focus of this chapter is on the part of Sauropsida traditionally called "reptiles". But Sauropsida also includes the dinosaurs and birds. Birds and dinosaurs are much more closely related to each other than they are to the other sauropsids and neither is really considered a reptile. So Sauropsida is messy and the term "reptile" is only useful in a non-scientific sense.

Simply because dinosaurs look superficially like reptiles, they are included at the end of this chapter. Birds, the living representatives of dinosaurs, will be explored in the next chapter.

Resources:

[ Previous Page ][ Next Page ]