[4] Sea spiders in this genus feature an unsegmented trunk, a low ocular tubercle, and a well-developed abdomen.

The palps and ovigers touch at their bases, and the strigilis is tightly curved with a strong terminal claw.

The ventral surface of the second most proximal article (second coxa) of some or all of these legs features tiny genital pores.

[6] The molecular evidence also indicates that both Decolopoda and Dodecolopoda are nested within a monophyletic group containing the "longitarsal" species in the genus Colossendeis.

This clade includes not only Antarctic species of Colossendeis such as C. australis and C. glacialis but also widespread taxa such as C. megalonyx and C. robusta.