There are a total of 653 Reptiles that have been compiled and organized in this comprehensive list. The selection includes extant, species-level entries with widely accepted common names and verified scientific names, excluding extinct or doubtful taxa.

Reptiles are cold-blooded vertebrates with scales or scutes, adapted for life on land, in water, or both. They include turtles, crocodilians, lizards, snakes, and the tuatara, showing wide forms and behaviors across climates. Many species play key ecological roles as predators, prey, and indicators of environmental health. People value reptiles for research, cultural traditions, and as companion animals, which drives conservation interest.

Interesting and little-known facts about Reptiles:
– More than 11,000 described reptile species exist worldwide, with new species added regularly to The Reptile Database.
– Reptile lineages appear in the fossil record over 300 million years ago, making them ancient components of terrestrial ecosystems.
– Some crocodilians reach over 700 cm in total length, while some dwarf chameleons and geckos measure under 20 mm as adults.
– Many reptiles use temperature-dependent sex determination, where incubation temperature rather than chromosomes sets offspring sex.
– Sea turtles can migrate more than 10,000 km between feeding and nesting sites, connecting distant marine habitats.

The alphabetical index directs users to A–Z lists of common-name entries organized by their initial letter. Each list shows common and scientific names, including habitat; adult size with measurement type (total length, SVL, carapace length); range; sources; and last-updated date.