What Is a Reptile?

What Is a Reptile? | Myths and Folklore | Benefits of Reptiles | Threats to Reptiles | Glossary | Scutellation | References


In the most general of terms, a reptile is a poikilothermic (erroneously called "cold-blooded") animal  which has an impermeable skin (unlike amphibians), breathes air (unlike most fish), and can reproduce on land (unlike fish and amphibians).



Bear in mind that taxonomy can change.  As more is learned about living things, the relationships between them and how we classify them is updated.  Some scientists use more levels of classification; others use less.  The information I present here should be generally acceptable.

All living things are classified into one of 5 kingdoms.  Reptiles belong to the kingdom Animalia (animals).

The kingdom Animalia is further divided into over 33 phyla.  The phylum to which reptiles belong is Chordata (animals which have a notochord, and are bilaterally symmetric).  

The phylum Chordata is further divided into 3 subphyla.  Reptiles belong to the subphylum Vertebrata (animals with backbones).

Vertebrata is broken down into 8 classes.  All reptiles belong to the class Reptilia.  Reptilia is organized into the following subclasses:

  • Anapsida (turtles)
  • Lepidosauria (tuatara, lizards, amphisbaenids, and snakes)
  • Archosauria (alligators and crocodiles)

The subclass Anapsida contains the order Testudines (Chelonia).  There are no other living orders within Anapsida.  The subclass Lepidosauria contains the orders Rhynchocephalia (tuatara) and Squamata (lizards, snakes, and amphisbaenids).  The subclass Archosauria contains only one living order, Crocodylia.

The subclasses are further broken down into superfamilies, families, subfamilies, and so on through the familiar Latin-based system of binomial nomenclature (genus and species).  

On each of the species accounts in the Field Herping pages, a classification is given beginning with Order and working down to subspecies level (where applicable).

If you are interested in learning more about reptilian taxonomy/phylogeny, consult the EMBL Reptile Database.


Examples of Reptiles
  • Snakes
  • Lizards
  • Turtles
  • Tortoises
  • Alligators
  • Crocodiles
  • Caiman
  • Gavials
  • Tuatara
  • Amphisbaenids


Examples of Animals Mistaken for Reptiles
  • Frogs/Toads (amphibians)
  • Salamanders/Newts (amphibians)
  • Caecilians (amphibians)
  • Worms (not vertebrates!)
  • Armadillos (mammals)