The atlas begins the historical Agnatha navigation grade at a rounded 520 Ma to include the Chengjiang Myllokunmingia and Haikouichthys specimens described as agnathan-grade vertebrates; 0 Ma reflects living cyclostomes in the display group, not a monophyletic crown range, global first appearance or direct ancestry. This navigation entry is not a phylogeny or a complete taxon dossier.
Represented range520–Present Ma
Content packageearly-fishes
PBDBNot linked
Evidence boundary
Automated checks cover structure, identifiers, translations and links only; maintainer and external expert review are not complete.
Claim ledger
fossil-range · medium
The atlas begins the historical Agnatha navigation grade at a rounded 520 Ma to include the Chengjiang Myllokunmingia and Haikouichthys specimens described as agnathan-grade vertebrates; 0 Ma reflects living cyclostomes in the display group, not a monophyletic crown range, global first appearance or direct ancestry.
claim:taxon:agnatha:fossil-range
Known limits
A missing branch or fossil occurrence does not imply biological absence. Internal nodes are not calibrated divergence estimates.