Epiophlebiidae

Definition

The sole living family of the infraorder Epiophlebioptera (Odonata), containing only the genus Epiophlebia. These relict damsel-dragonflies are endemic to montane streams of the Indian subcontinent, East Asia, and Southeast Asia. Epiophlebiidae represents a phylogenetically isolated lineage that bridges dragonfly and damselfly morphology: adults have dragonfly-like wings held horizontally at rest, but possess damselfly-like separated eyes and larval gills. The family is frequently cited in discussions of odonate evolution and the paraphyly of traditional subordinal classifications.

Etymology

From the type genus Epiophlebia (Greek: epi- 'upon, in addition to' + ophis 'serpent, snake' + plebios 'life, living being', alluding to the snake-like flight pattern) + -idae (family suffix).

Example

Larvae of Epiophlebia superstes in Japanese mountain streams possess unique ventral gill structures intermediate between the rectal gills of dragonflies and the caudal gills of damselflies, supporting the family's placement as sister to all other extant odonates.

Related Terms

• Epiophlebia
• Epiophlebioptera
• Odonata
• Anisozygoptera
• Anisoptera
• Zygoptera
• relict taxon
• phylogenetic bridge taxon

Usage Notes

Historically grouped with fossil lineages under 'Anisozygoptera,' but molecular and morphological studies have shown this assemblage to be paraphyletic. Modern treatments recognize Epiophlebiidae as the only extant representative of Epiophlebioptera, distinct from both Anisoptera (dragonflies) and Zygoptera (damselflies). The family is sometimes called 'damsel-dragonflies' in English, though this is a descriptive nickname, not a formal synonym.