saurus

Saurus is a suffix used in the scientific naming of reptiles and, most famously, of many dinosaurs. It derives from the Greek word sauros, meaning lizard or reptile, and is usually rendered in Latinized form as -saurus in genus names. The suffix signals a reptilian lineage in the traditional taxonomic practice of early modern biology, though it does not by itself indicate any particular evolutionary relationship.

In paleontology and broader reptile taxonomy, -saurus appears at the end of numerous genus names. Well-known examples include Tyrannosaurus, Stegosaurus, Allosaurus, Spinosaurus, and Apatosaurus. The use is largely historical and conventional, reflecting the naming styles of paleontologists who first described these organisms. Names ending with -saurus often invoke a sense of ancient or dinosaurian biology for popular audiences.

The suffix is not a taxonomic rank and does not convey a single diagnostic characteristic. It functions as part of a genus name, with related genera potentially belonging to different families or higher groups. Variants such as -sauros occur in some names, but -saurus remains the most common Latinized form in modern usage. In contemporary science, the practice of naming new genera with -saurus continues to be rare but persists in stylistic tradition rather than reflecting a universal nomenclatural rule.