Editing Eocene (section)

==Etymology==
The term "Eocene" is derived from [[Ancient Greek]] {{lang|grc|Ἠώς}} (''Ēṓs'') meaning "Dawn", and {{lang|grc|καινός}} ''kainos'' meaning "new" or "recent", as the epoch saw the dawn of recent, or modern, life.

Scottish geologist [[Charles Lyell]] (ignoring the Quaternary) divided the Tertiary Epoch into the Eocene, [[Miocene]], [[Pliocene]], and New Pliocene ([[Holocene]]) [[geological period|Periods]] in 1833.<ref>{{cite book|first=C.|last=Lyell|author-link=Charles Lyell|year=1833|title=Principles of Geology|volume=3|publisher=Geological Society of London|page=[https://archive.org/details/in.ernet.dli.2015.45031/page/n382 378]|url=https://archive.org/details/in.ernet.dli.2015.45031}}</ref>{{refn |In Lyell's time, epochs were divided into periods. In modern geology, periods are divided into epochs.| group=n }} British geologist [[John Phillips (geologist)|John Phillips]] proposed the [[Cenozoic]] in 1840 in place of the Tertiary,<ref>{{cite book |last1=Phillips |first1=J.|author-link=John Phillips (geologist) |title=Penny Cyclopaedia of the Society for the Diffusion of Useful Knowledge |volume= 17 |date=1840 |publisher=Charles Knight and Co. |location=London, England |pages=153–154 |chapter-url=https://babel.hathitrust.org/cgi/pt?id=hvd.hn4zr7;view=1up;seq=162 |chapter=Palæozoic series}}</ref> and Austrian paleontologist [[Moritz Hörnes]] introduced the [[Paleogene]] for the Eocene and [[Neogene]] for the Miocene and Pliocene in 1853.<ref>{{cite journal |last1=Hörnes |first1=M. |author-link=Moritz Hörnes|title=Mittheilungen an Professor Bronn gerichtet |journal=Neues Jahrbuch für Mineralogie, Geognosie, Geologie und Petrefaktenkunde |year=1853 |pages=806–810 |url=https://babel.hathitrust.org/cgi/pt?id=hvd.32044106271273;view=1up;seq=828 |trans-title=Reports addressed to Professor Bronn |language=de|hdl=2027/hvd.32044106271273}}</ref> After decades of inconsistent usage, the newly formed [[International Commission on Stratigraphy]] (ICS), in 1969, standardized stratigraphy based on the prevailing opinions in Europe: the Cenozoic Era subdivided into the Tertiary and Quaternary sub-eras, and the Tertiary subdivided into the Paleogene and Neogene periods.<ref>{{cite journal|first1=T. N.|last1=George|first2=W. B.|last2=Harland|year=1969|title=Recommendations on stratigraphical usage|journal=Proceedings of the Geological Society of London|volume=156|issue=1,656|pages=139–166}}</ref> In 1978, the Paleogene was officially defined as the Paleocene, Eocene, and Oligocene epochs; and the Neogene as the Miocene and Pliocene epochs.<ref>{{cite journal |first1=G. S. |last1=Odin |first2=D. |last2=Curry |first3=J. Z. |last3=Hunziker |year=1978 |title=Radiometric dates from NW European glauconites and the Palaeogene time-scale |journal=[[Journal of the Geological Society]] |volume=135 |issue=5 |pages=481–497 |doi=10.1144/gsjgs.135.5.0481 |bibcode=1978JGSoc.135..481O |s2cid=129095948}}</ref> In 1989, Tertiary and Quaternary were removed from the time scale due to the arbitrary nature of their boundary, but Quaternary was reinstated in 2009.<ref>{{cite journal|first1=R. W. O.'B. |last1=Knox |first2=P. N. |last2=Pearson |first3=T. L. |last3=Barry |year=2012 |title=Examining the case for the use of the Tertiary as a formal period or informal unit |journal=Proceedings of the Geologists' Association |volume=123 |issue=3 |pages=390–393 |doi=10.1016/j.pgeola.2012.05.004 |bibcode=2012PrGA..123..390K |url=http://discovery.ucl.ac.uk/1398932/2/1398932.pdf |doi-access=free}}</ref>