Megachelicerax cousteaui gen. et sp. nov. is described from holotype KUMIP 314091a,b; the profiled stem-chelicerate assignment remains a phylogenetic result, not direct ancestry.
claim:taxon:megachelicerax:taxonomyMegachelicerax
Holotype KUMIP 314091a,b preserves massive three-segmented chelicerae and a pseudobiramous body plan in a middle Cambrian stem-chelicerate analysis.
Represented range504.5–500.5 Ma
Content packagetrilobites-chelicerates
PBDBtxn:519118
Evidence boundary
Automated checks cover structure, identifiers, translations and links only; maintainer and external expert review are not complete.
Claim ledger
This profile is restricted to the Drumian Wheeler Formation holotype from Utah and does not establish a global Megachelicerax distribution.
claim:taxon:megachelicerax:biogeographyLarge predatory ecology is inferred from massive chelicerae and body-plan comparisons; prey, behaviour and locomotor performance are not directly preserved.
claim:taxon:megachelicerax:ecologyKUMIP 314091a,b directly preserves massive three-segmented chelicerae, five pseudobiramous post-cheliceral prosomal limb pairs and plate-like lamellae-bearing opisthosomal appendages.
claim:taxon:megachelicerax:morphologyBayesian and parsimony analyses recover Megachelicerax on the chelicerate stem between sampled Cambrian habeliids and post-Cambrian synziphosurines; this topology is not a direct ancestor–descendant sequence.
claim:taxon:megachelicerax:topologyMegachelicerax is bounded here by holotype KUMIP 314091a,b from the Drumian Wheeler Formation of Utah; this named holotype context is not a global distribution or exact complete range.
claim:taxon:megacheliceraxKnown limits
- A missing branch or fossil occurrence does not imply biological absence. Internal nodes are not calibrated divergence estimates.
References
- A chelicera-bearing arthropod reveals the Cambrian origin of cheliceratesLerosey-Aubril, R.; Ortega-Hernández, J. · 2026 · DOI 10.1038/s41586-026-10284-2
- Open Tree of Life web servicesOpenTreeOfLife Project
- The Paleobiology Database application programming interfacePeters, S.E.; McClennen, M. · 2016 · DOI 10.1017/pab.2015.39
- Denormalized occurrence and taxon tables of the Paleobiology DatabaseThe Paleobiology Database Community; Kocsis, Á.T. · 2026 · DOI 10.5281/zenodo.21620933