By Conrad Philson4th Period Biology

REPTILES

There are four living orders of Reptiles:

Crocodilia• The reptilian order

crocodilia appeared about 84 million years ago, in the late Cretaceous period.

• These are the closest living relatives to birds, as both groups are the last known survivors of archosauria, otherwise known as Dinosaurs.

Sphenodontia

• The order sphenodontia only has one living genus, the tuataras. Within that genus, there is only two species.

• The tuataras are endemic (ecologically isolated) to New Zealand, one species on northern islands while the other in the south.

Squamata• The order squamata

consists of approximately 7900 species which are mainly lizards, snakes, and worm lizards.

• Squamata is the most variably sized order of reptiles, ranging from the 6/10 of an inch dwarf gecko to the up-to 26 foot green anaconda.

Testudines• Testudines are the order of turtles, tortoises, and terrapins.

Testudines are characterized by a special bony or cartilaginous shell developed from their rib cage that acts as a special shield.

• Testudines go back approximately 215 million years ago to the Triassic period, making them the most ancient surviving reptilian group.

Bibliography • http://en.wikipedia.org/wiki/Reptiles• http://en.wikipedia.org/wiki/File:NileCrocodile.jpg• http://www.earlham.edu• http://en.wikipedia.org/wiki/File:Florida_Box_Turtle_Digon3_re-edited.jpg• http://en.wikipedia.org/wiki/File:Chelonia_mydas_is_going_for_the_air.jpg• http://en.wikipedia.org/wiki/File:Turtle1.jpg• http://en.wikipedia.org/wiki/File:Anakonda_verschlingt_Wildschein_Senckenberg.jpg• http://en.wikipedia.org/wiki/File:Underwoodisaurus_milii.jpg