Epigynes

Epigynes are a type of female genitalia found in some species of reptiles, particularly in the families Agamidae and Gekkonidae. They are characterized by a pair of openings on the underside of the tail, which serve as the female reproductive organs. These openings are used for both copulation and egg-laying. The term "epigyne" comes from the Greek words "epi," meaning "on," and "gynē," meaning "woman," reflecting the location of these openings.

The presence of epigynes is a unique adaptation that allows these reptiles to lay their eggs in a manner similar to birds, where the eggs are deposited externally rather than internally. This adaptation is thought to have evolved as a means of reducing the risk of predation on the eggs. The eggs are typically laid in a clutch, and the female may guard them until they hatch.

Epigynes are not found in all species of reptiles. In many other species, the female reproductive organs are located internally, and the eggs are laid internally as well. The presence of epigynes is a distinctive feature of certain reptile species and is an important aspect of their biology and behavior.