Move from contested Cryogenian molecules through named Ediacaran and Cambrian fossils to living genomes, coral clocks and ecological proxies while keeping compounds, specimens, topology, model time and COL26.8 names distinct.
Each step names its evidence claims, with references below. Interactive Explorer states are available in the full application; the narrative remains an editorial synthesis.
The Oman steranes are real measurements, but Rhizaria make relevant precursors. The package records a contested source attribution rather than a Cryogenian sponge fossil.
Chemical occurrence and taxonomic diagnosis stay separate.
claim:event:cryogenian-sponge-biomarker-debateEocyathispongia preserves striking cellular organization, but the dossier does not turn funnel-like openings into a secure crown-sponge diagnosis.
Imaged anatomy is firmer than affinity.
claim:event:eocyathispongia-single-specimenHelicolocellus combines repeated body-wall grids with a morphology-matrix placement. Architecture is observed; hexactinellid affinity is inferred.
Organic skeleton and siliceous spicule are not synonyms.
claim:event:helicolocellus-organic-skeletonThe Soltanieh spicules survive a candidate-by-candidate reassessment, while older claims fail different taphonomic or diagnostic tests.
A review boundary is revisable, not eternal.
claim:event:soltanieh-basal-cambrian-spiculesAmphimedon retains extensive animal gene machinery. Comparative presence does not mean a sponge expresses bilaterian organs or mirrors the first animal.
Genome content and phenotype remain distinct evidence.
claim:event:amphimedon-draft-genomePorifera-sister and Ctenophora-sister each have genome-scale support. The atlas exposes the conflict instead of selecting a silent consensus.
Support values are conditional, not votes from nature.
claim:event:animal-root-competing-modelsAuroralumina supplies a crown-cnidarian hypothesis from a dated surface, while preserved anatomy and phylogenetic placement remain separate.
One surface can test, not settle, a crown.
claim:event:auroralumina-charnwood-polypsAt approximately 560 Ma, Haootia shows ordered linear structures. Muscle and staurozoan readings remain explicit hypotheses with supporting and opposing studies.
Visible pattern and tissue identity are different claims.
claim:event:haootia-muscle-interpretationOu et al. recover a stem-cnidarian body plan, whereas Zhao et al. recover Dinomischidae on the ctenophore stem; alternative coding leaves a polytomy.
Synonymy, anatomy and topology each need evidence.
claim:event:xianguangia-body-plan-testBurgessomedusa supplies macroscopic medusa anatomy by the middle Cambrian. It is a bounded fossil sample, not the origin event itself.
Minimum evidence is not a complete history.
claim:event:burgessomedusa-swimming-medusaThe map fixes Burgessomedusa to Raymond Quarry in British Columbia. It does not turn a single Burgess Shale sample into a worldwide distribution.
A site age is not a FAD or LAD.
claim:taxon:burgessomedusa:biogeographyBurgessomedusa has a cuboidal umbrella and more than ninety marginal tentacles. Comparison with living medusozoans is informative, but compression and coding sensitivity retain several placements.
Morphospace comparison is not a direct ancestor line.
claim:taxon:burgessomedusa:morphology · claim:taxon:burgessomedusa:taxonomyAmphimedon queenslandica was sampled from the Great Barrier Reef. The route maps the living sample and deliberately carries no numerical species fossil range.
Living occurrence does not date species origin.
claim:taxon:amphimedon_queenslandica:biogeographyThe study figures adult, embryo and larval stages alongside a draft genome. Sequence content and life stages are observations; an ancestral body plan is not.
Observed life history is not a Precambrian reconstruction.
claim:taxon:amphimedon_queenslandica:morphologyComparative gene-family results document a living demosponge genome and test deep animal relationships. They do not make Amphimedon a stand-in for all Porifera or the first animal.
Comparative ancestry remains an inference.
claim:taxon:amphimedon_queenslandica:taxonomyThe sampled matrix supports Anthozoa and Medusozoa and several internal groups, but Ceriantharia keeps Hexacorallia uncertain.
A supported subset is not a universal tree.
claim:event:cnidarian-phylogenomic-sampleMyxozoan genomes place microscopic parasites inside Cnidaria. Their reduced bodies do not represent the ancestral cnidarian condition.
Secondary loss must not be read as primitiveness.
claim:event:myxozoan-genome-reductionDeep-water coral genes support an older split than the familiar Triassic skeleton record. Model time and fossil time stay separate.
A posterior interval is not a hidden fossil.
claim:event:scleractinian-paleozoic-clockLate-Triassic corals carry several proxy signals consistent with photosymbiosis. The symbiont is inferred, not fossilized.
Proxy agreement strengthens but does not become direct observation.
claim:event:triassic-coral-photosymbiosis