🦎 Reptiles: Masters of Land and Water
Class Reptilia — Cold-blooded vertebrates with scales, lungs, and shelled eggs
🔬 What Are Reptiles?
Reptiles (Class Reptilia) are cold-blooded vertebrates characterized by lungs for respiration and skin covered in scales or scutes. This class comprises over 11,000 species and is amniote, meaning their embryos develop within a protective amniotic membrane.
Key Term — Ectotherm: An organism whose body temperature depends on external heat sources (the environment), rather than generating its own internal heat. Reptiles are ectotherms and poikilotherms (their body temperatures vary with the surroundings).
The Four Main Orders of Reptiles
🦎
Squamata
Lizards & Snakes
~11,000 species
🐢
Chelonia
Turtles & Tortoises
~360 species
🐊
Crocodilia
Crocodiles & Alligators
~27 species
🦴
Rhynchocephalia
Tuataras
1 species (New Zealand)