Mollisonia symmetrica combines neuroanatomical and appendicular signals that support competing placements; the profile does not select a direct ancestor.
claim:taxon:mollisonia:taxonomyMollisonia
Carbonaceous films in two specimens preserve optic nerves, a possible cephalic synganglion and a segmental ventral nerve cord in a contested stem-chelicerate context.
Represented range508.1–505 Ma
Content packagetrilobites-chelicerates
PBDBtxn:19082
Evidence boundary
Automated checks cover structure, identifiers, translations and links only; maintainer and external expert review are not complete.
Claim ledger
The profile is bounded to the cited Burgess Shale specimens and does not infer the genus’s complete distribution.
claim:taxon:mollisonia:biogeographyThe profiled Mollisonia symmetrica neural specimens do not establish diet or guild; separately, M. plenovenatrix appendages support a benthic-micropredator interpretation for that species, not every Mollisonia.
claim:taxon:mollisonia:ecologyMCZ 1811 and USNM 305093 preserve optic nerves, a possible compact synganglion and a segmental ventral nerve cord as carbonaceous films.
claim:taxon:mollisonia:morphologyThe 508.1–505 Ma interval is a Burgess Shale sample envelope, not a global genus duration or chelicerate divergence time.
claim:taxon:mollisonia:fossil-rangeKnown limits
- A missing branch or fossil occurrence does not imply biological absence. Internal nodes are not calibrated divergence estimates.
References
- Neuroanatomy in a middle Cambrian mollisoniid and the ancestral nervous system organization of cheliceratesOrtega-Hernández, J.; Lerosey-Aubril, R.; Losso, S.R.; Weaver, J.C. · 2022 · DOI 10.1038/s41467-022-28054-9
- 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
- A middle Cambrian arthropod with chelicerae and proto-book gillsAria, C.; Caron, J.-B. · 2019 · DOI 10.1038/s41586-019-1525-4