The numerical age of the Cambrian base is revised to 538.8 Ma
node
The base of the Cambrian, and with it the base of the Phanerozoic, has carried several different numerical ages while its defining point at Fortune Head has not moved: figures near 542 Ma, then 541.0 ± 1.0 Ma on charts widely cited through the 2010s, and 538.8 ± 0.2 Ma on recent editions. This record exists to make that change legible rather than to hide it, because the declared timeline for this Journey still gives ~541 Ma. The specific chart edition in which the revision took effect was not confirmed in this session, which is why this event is recorded as uncertain — the change itself is not in doubt, its exact publication is.
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