One large soft-bodied holotype preserves unequivocal three-segmented chelicerae in a Cambrian stem chelicerate.
Represented range504.5–500.5 Ma
RegionsWheeler Formation, Utah, USA
CladesMegachelicerax cousteaui · Chelicerata
Claim ledger
topology · high
Megachelicerax cousteaui holotype KUMIP 314091a,b directly preserves massive three-segmented chelicerae, five post-cheliceral prosomal limb pairs and lamellate opisthosomal appendages; predation and its bridging stem-chelicerate position are functional and phylogenetic interpretations.