eureptile

Eureptilia is a proposed taxonomic clade that encompasses all extant reptiles and birds. The name itself is derived from Greek and Latin, meaning "true reptiles." This grouping is based on evolutionary relationships, suggesting that birds evolved from a lineage of theropod dinosaurs, which are themselves considered reptiles. Therefore, eureptiles would include all amniotes that are not synapsids, which are the lineage that led to mammals.

The concept of eureptilia arises from cladistic analysis, a method of classifying organisms based on shared ancestry. Proponents of this classification argue that it provides a more accurate reflection of evolutionary history than traditional groupings. Traditional herpetology, for instance, often treats reptiles and birds as separate classes, despite the overwhelming evidence for their close evolutionary connection.

Within eureptilia, the major extant groups would include turtles, lepidosaurs (lizards, snakes, and tuataras), crocodilians, and birds. The precise placement and definition of eureptilia can vary slightly depending on the specific phylogenetic studies and interpretations. However, the core idea remains consistent: to group all descendants of the most recent common ancestor of all living reptiles and birds. The inclusion of birds within a reptilian clade is a significant departure from older classification systems but is widely supported by modern paleontology and molecular biology.