The Paleobiology Database application programming interface

A class-level ophiuran occurrence represented by Stenaster from the Wah Wah Formation is Floian in age; the atlas therefore uses the Floian base only as a stage ceiling for the Ophiuroidea body-fossil record.

Oesolcucumaria eostre from the late Darriwilian Holothurian Bed of Wales is the oldest articulated holothurian used here, and its calcareous ring provides an unequivocal class assignment; a disputed Cambrian PBDB identification is not used as the range endpoint.

The cited Stenaster record is from the Floian Wah Wah Formation of Utah, United States; it is a source-bounded occurrence rather than a global ophiuran distribution or origin claim.