The unproblematic crinoid fossil record begins in the middle Tremadocian; the Middle Cambrian Echmatocrinus is problematic and is not used here as the Crinoidea first appearance.
claim:taxon:crinoidea:tremadocian-recordCrinoidea
A class-level profile anchored to a systematic treatment of early crinoid taxa; it keeps the middle Tremadocian unproblematic record separate from the problematic Middle Cambrian Echmatocrinus assignment.
Represented range482–Present Ma
Content packageechinoderms
PBDBtxn:31590
Evidence boundary
Automated checks cover structure, identifiers, translations and links only; maintainer and external expert review are not complete.
Claim ledger
The cited systematic study treats named early crinoid taxa and explicitly keeps problematic Middle Cambrian Echmatocrinus outside the unproblematic Crinoidea record used by this profile.
claim:taxon:crinoidea:taxonomyThe cited early-crinoid systematic material supplies source-bounded fossil locality context, not a global distribution, endemicity or dispersal reconstruction for Crinoidea.
claim:taxon:crinoidea:biogeographyThe cited systematic study does not establish class-wide diet, habitat preference, locomotor performance, body-size distribution or guild for Crinoidea; these fields remain explicitly unresolved beyond marine fossil context.
claim:taxon:crinoidea:ecologyThe source documents anatomical characters in named early crinoid taxa, while the profile keeps those observations source-bounded and does not present them as an invariant class-wide character list.
claim:taxon:crinoidea:morphologyKnown limits
- A missing branch or fossil occurrence does not imply biological absence. Internal nodes are not calibrated divergence estimates.
References
- Athenacrinus n. gen. and other early echinoderm taxa inform crinoid origin and arm evolutionGuensburg, T.E.; Sprinkle, J.; Mooi, R.; Lefebvre, B.; David, B.; Roux, M.; Derstler, K.L. · 2020 · DOI 10.1017/jpa.2019.87
- 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