Apterous

Definition

Lacking wings entirely; describes the anatomical condition of an animal without functional or vestigial wings, whether primitively so (never evolved wings) or secondarily (ancestrally winged lineage that has lost them). In entomology, distinguishes wingless insects from brachypterous (short-winged) or micropterous (reduced-winged) conditions.

Etymology

From Greek apteros, 'wingless' (a-, 'without' + pteron, 'wing')

Example

Bristletails (Archaeognatha) are primitively apterous, having diverged before wing evolution; fleas (Siphonaptera) are secondarily apterous, having lost the wings of their Mecopteran ancestors.

Synonyms

• wingless

Related Terms

• aptery
• Apterygote
• brachypterous
• Micropterous
• Elytra
• Hemelytra

Usage Notes

Contrast with brachypterous (shortened, non-functional wings present) and micropterous (small but present wings). Apterous is absolute: no wings or wing remnants. The term applies to any wingless arthropod but is most precise for insects. Some specialists reserve 'apterous' for secondarily wingless taxa and use 'apterygote' for primitively wingless groups, though usage overlaps considerably.