Basic Animal Groups


The first reptile found was dated around 315 million years ago, in the Carboniferous period. Was evolved from advanced reptile-like amphibians that became increasingly adapted to life on dry land.
Living reptiles have scales or scutes, are cold-blooded, and lays eggs. Reptiles are tetrapod vertebrates, either having four limbs or, like snakes, being descended from four-limbed ancestors.

Modern reptiles can be found on every continent, except Antarctica.

Reptiles are splited in four subclasses:
Anapsida no fenestrae cotylosaurs and Chelonia (turtles and relatives)
Synapsida one low fenestra pelycosaurs and therapsids (the 'mammal-like reptiles')
Euryapsida one high fenestra (above the postorbital and squamosal) proto

rosaurs (small, early lizard-like reptiles) and the marine sauropterygians and ichthyosaurs.
Diapsida two fenestrae most reptiles, including lizards, snakes, crocodilians, dinosaurs and pterosaurs.

Classification to order level, after Benton, in 2005:

Series Amniota
  Class Synapsida
        Order Pelycosauria
        Order Therapsida
  Class Mammalia

  Class Sauropsida
    SubClass Anapsida
        Order Testudines (turtles)
A series of unassigned anapsid families, corresponding to Captorhinida, Mesosauria and Procolophonomorpha

    SubClass Diapsida
        Order Araeoscelidia
        Order Younginiformes
InfraClass Ichthyosauria
InfraClass Lepidosauromorpha
SuperOrder Sauropterygia
        Order Placodontia
        Order Nothosauroidea
        Order Plesiosauria

SuperOrder Lepidosauria
        Order Sphenodontia (tuatara)
        Order Squamata (lizards & snakes)

InfraClass Archosauromorpha
        Order Prolacertiformes
Division Archosauria
Subdivision Crurotarsi
SuperOrder Crocodylomorpha
        Order Crocodilia
        Order Phytosauria
        Order Rauisuchia
        Order Rhynchosauria

Subdivision Avemetatarsalia
Infradivision Ornithodira
        Order Pterosauria
SuperOrder Dinosauria
        Order Ornithischia
        Order Saurischia

  Class Aves


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