Table 2.
One proposal for matching temporal bands of classification rank to the geological time scale
| Taxonomic rank* | Geological episode | Temporal band† |
|---|---|---|
| Domain(A) | Archaean | 2.5–3.6 Bya |
| Kingdom(B) | Proterozoic | 0.55–2.5 Bya |
| Phylum(C) | Cambrian | 500–550 Mya |
| Subphylum(D) | Ordovician | 440–500 Mya |
| Superclass(E) | Silurian | 410–440 Mya |
| Class(F) | Devonian | 350–410 Mya |
| Subclass(G) | Carboniferous | 290–350 Mya |
| Cohort(H) | Permian | 250–290 Mya |
| Superorder(I) | Triassic | 205–250 Mya |
| Order(J) | Jurassic | 145–205 Mya |
| Suborder(K) | Cretaceous | 65–145 Mya |
| Superfamily(L) | Paleocene | 56–65 Mya |
| Family(M) | Eocene | 33–56 Mya |
| Subfamily(N) | Oligocene | 24–33 Mya |
| Tribe(O) | Miocene | 5–24 Mya |
| Genus(P) | Pliocene | 2–5 Mya |
| Subgenus(Q) | Pleistocene | 0–2 Mya |
| Species‡— | — | — |
Mya, million years ago; Bya, billion years ago.
*
All categories except Domain are from ref. 6.
†
Within which the relevant phylogenetic node falls (from ref. 22).
‡
The current proposal does not extend to species-level taxonomic assignments, where biological criteria including reproductive isolation should be applied (see ref. 42).