[1] A well-known member is the peppered moth, Biston betularia, which has been the subject of numerous studies in population genetics.

The name "Geometridae" ultimately derives from Latin geometra from Greek γεωμέτρης ("geometer", "earth-measurer").

They tend to be green, grey, or brownish and hide from predators by fading into the background or resembling twigs.

Described under Eogeometer vadens, it measured about 5 mm (0.20 in) and was estimated to be 44 million years old, dating back to the Eocene epoch.

[5] Many geometrids have slender abdomens and broad wings which are usually held flat with the hindwings visible.

Traditionally, the Archiearinae were held to be the most ancient of the geometer moth lineages, as their caterpillars have well-developed prolegs.

As regards the Archiearinae, some species that were traditionally placed therein actually seem to belong to other subfamilies; altogether it seems that in a few cases, the prolegs which were originally lost in the ancestral geometer moths re-evolved as an atavism.