This family is sometimes massively expanded, with the closely related Bistonini, Bupalini, Erannini, Gnophini, Melanolophini, Phaseliini and Theriini all merged into it.

The eggs of all these geometer moths have the chorion cells characteristically arranged in longitudinal rows.

Typically, they are cryptically colored and rather dark, with brownish-grey hues predominating; in many, there are two or three weak wavy bands extending across the wings and forming a rough semicircle when the moths are at rest.

The valva and harpe (or "clasper") of the male genitalia are highly complex in almost all species and often bear various extensions.

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