A revised shell-character classification diagnoses and reorganizes sampled spiriferid brachiopods; it supports the systematic unit but does not establish a global first appearance, extinction boundary or direct ancestor.
claim:taxon:spiriferidaA revised classification of the spiriferid brachiopods
Carter, J.L.; Johnson, J.G.; Gourvennec, R.; Hou, H.-F.
Year1994
Source rolesystematic-review
DOI / ID10.5962/p.215817
Fitness and scope
taxonomy · morphology · range
Order-level systematic revision based on shell characters; p. 329 explicitly states an Upper Ordovician–Upper Permian stratigraphic range, while classification does not establish direct ancestry or continuous occupancy.
Claim ledger
Carter et al. state an Upper Ordovician–Upper Permian stratigraphic range for Spiriferida; the atlas displays 458.2–251.902 Ma by converting those named bounds with ICS v2026/06, not as direct dates, continuous occupancy or an ancestor sequence.
claim:taxon:spiriferida:source-bounded-range-rc50