What are the four main types of reptiles?

Reptiles are a group of four-legged vertebrates (also known as tetrapods) that diverged from ancestral amphibians approximately 340 million years ago. There two characteristics that early reptiles developed that set them apart from their amphibian ancestors and that enabled them to colonize land habitats to a greater extent than amphibians. read more

The Challenges of Reptile Classification. Reptiles can be quite challenging to classify. There are two main reasons for this — scientific disagreement and scientific advancement. Actually, these two things are closely related, as they pertain to reptile classification and species names. read more