Cheliceromorpha is a proposed clade of arthropods comprising Megacheira and Chelicerata. It is equivalent to total-group Chelicerata with the exclusion of Artiopoda (trilobite and relatives). Defining traits of Cheliceromorpha including a deutocerebral (align to the second brain segment) pair of raptorial appendages with 6 or less segments (e.g. great appendages, chelicerae), and exites of trunk appendages with overlapping lamellae which evolved into book gills in crown-group chelicerates.
See also
Arachnomorpha
References