Lycaenidae is the second-largest family of butterflies, with over 6,000 species worldwide, whose members are also called gossamer-winged butterflies. They constitute about 30% of the known butterfly species.

Butterflies are winged insects from the lepidopteran suborder Rhopalocera, characterized by large, often brightly coloured wings that often fold together when at rest, and a conspicuous, fluttering flight. The group comprises the superfamilies Hedyloidea and Papilionoidea. The oldest butterfly fossils have been dated to the Paleocene, about 56 million years ago, though they likely originated in the Late Cretaceous, about 101 million years ago.