Pliocene
Younger epoch of the Neogene, originally distinguished by fossil shell faunas with a higher proportion of living species than the Miocene.
Language and route: English Pliocene, coined with Greek combining elements. Charles Lyell’s English geological coinage (1833) from Greek pleíōn, ‘more’, and kainós, ‘new, recent’.
Literal gloss: more recent [living species]
The name and its history
Charles Lyell (with palaeontological work by G. P. Deshayes) · 1833
- What does the word literally mean?
- ‘More recent’ compares the proportion of fossil marine mollusc species assigned to living species in younger Tertiary assemblages with that in the Miocene. It is not a general claim that more fossils formed during the Pliocene.
- What did the original author mean?
- Lyell meant ‘more recent’ because relatively many fossil marine mollusc species matched species still living.
- Why was the name needed?
- He needed a grouping for strata younger than the Miocene, later subdividing its older and newer parts.
- What evidence supported the original concept?
- Lyell’s own estimates included more than one-third extant species in older Pliocene samples, with larger proportions in younger beds.
- How has geology changed the concept?
- The younger part was subsequently renamed and reinterpreted as Pleistocene; Pliocene limits are now formal chronostratigraphic boundaries.
Further historical context
Lyell introduced the name in 1833 for a younger set of Tertiary deposits, initially separating Older and Newer Pliocene strata. Some sampled Pliocene fossil mollusc assemblages were then estimated to have more than one-third, and sometimes a very high proportion, of species still living.
He later used the proposed word Pleistocene for part of the Newer Pliocene, then publicly complained about the ambiguity that arose as different researchers applied it differently. Modern Pliocene limits are fixed through international stratigraphy, not fossil-shell percentages.
Editorial qualification
Lyell 1833 original method compares the percentage of fossil marine mollusc species considered extant; this is a historical taxonomic assumption and not the present chronostratigraphic test.
Related names
Miocene · Pleistocene · Holocene · Neogene · Fossil · Stratigraphy · Gelasian · Villafranchian
Sources
- Charles Lyell (1833), Principles of Geology, vol. 3 (digitised text) — Original fossil-mollusc method and explicit Eocene/Miocene/Pliocene explanations
- Charles Lyell (1863), Geological Evidence of the Antiquity of Man, ch. 1 — Author’s retrospective explanation, limitations of percentages and changed meaning of Pleistocene
- International Commission on Stratigraphy, Chart 2026/06 — Current formal ranks and boundaries; not evidence of etymological first usage