Uniramia Formerly a phylum or a subphylum of Arthropoda, in which the appendages are unbranched (i.e. uniramous) and at one time classed as members of the Mandibulata. The group includes the myriapods (centipedes and millipedes) and the insects, the earliest known fossils being Devonian and resembling modern centipedes and millipedes. The Arthropoda are now held to have evolved only once (they are monophyletic) and the formal and informal use of Uniramia has been abandoned, with its members reallocated to the subphylum Atelocerata.

Uniramia (Mandibulata) A phylum of arthropods that contains the classes Chilopoda (centipedes), Diplopoda (millipedes), Pauropoda and Symphyla (centipede-like animals), and Hexapoda (insects). Members are characterized by uniramous appendages.