The Quaternary now includes the Gelasian

They changed the beginning of the Quaternary! And here I thought the eras, periods, and epochs were written in stone.

In June 2009, the Executive Committee of the International Union of Geological Sciences (IUGS) formally ratified a proposal by the International Commission on Stratigraphy to lower the base of the Quaternary System/Period to the Global Stratotype Section and Point (GSSP) of the Gelasian Stage/Age at Monte San Nicola, Sicily, Italy. The Gelasian until then had been the uppermost stage of the Pliocene Series/Epoch. The base of the Gelasian corresponds to Marine Isotope Stage 103, and has an astronomically tuned age of 2.58 Ma.

← The quaternary period formerly started at 1.8 million years ago, but it has now been extended to include the Gelasian stage going back to 2.58 mya.

The vote was not unanimous; a significant (by the 5% level) of the 18 members of the International Commission on Stratigraphy (ICS) did not concur.

The results of the voting were overwhelmingly in favour of the SQS recommendations. In the final ballot, 89% of the ICS voting membership supported the Quaternary case. In May 2009, the ICS forwarded the results to the IUGS Executive Committee, and on 29 June 2009 that body formally ratified the SQS proposal. This brings closure to a debate that has run for more than six decades and, from a Quaternary perspective at least, the outcome is entirely satisfactory. In addition, with the imposition of the 10-year moratorium, this matter cannot be revisited until 2019 at the earliest.

The begging question is, of course, does it matter? Will this change anything we know? I'm fairly certain it won't, but that it's all just about agreeing on what to call what - even though this of course has to reflect what we know.

Reference:
Formal ratification of the Quaternary System/Period and the Pleistocene Series/Epoch with a base at 2.58 Ma
Philip L. Gibbard, Martin J. Head, Michael J. C. Walker, the Subcommission on Quaternary Stratigraph
Journal of Quaternary Science (2009)