Uniramia

From Freepedia

The Uniramia are a major group of Arthropoda, consisting of arthropods with a single pair of preoral antennae and a single pair of legs per segment, namely the Hexapoda (insects and allies) and Myriapoda (centipedes, millipedes, and related forms). In Manton's original proposal, the Uniramia also included the Onychophora (velvet worms), but the discovery of fossil lobopods that are intermediate between onychophorans and arthropods is strong evidence for the two groups being separate.

The Crustacea were generally considered the closest relatives of the Uniramia, and sometimes these were united as Mandibulata. However, the competing hypothesis — that Crustacea and Hexapoda form a monophyletic group, the Pancrustacea, to which the Myriapoda are the closest relatives — has support from molecular and fossil evidence.