| Cheliceromorpha Temporal range: | |
|---|---|
| Fossil of Leanchoilia superlata, a megacheiran | |
| Limulus polyphemus, a xiphosurid chelicerate | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Clade: | Deuteropoda |
| (unranked): | Cheliceromorpha Boudreaux, 1979 |
| Subgroups | |
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.