India, Oct. 14 -- When the International Union of Geological Sciences (IUGS) announced in 2018 that the youngest subdivision of the Holocene epoch would be called the Meghalayan Age, a ripple of pride passed across the northeastern hill state of Meghalaya.

The Mawmluh Cave near Cherrapunji in Meghalaya's East Khasi Hills district, became the "golden spike" - the official reference site to mark a new boundary in Earth's geological timeline, dated to about 4,200 years ago.

The Holocene is the epoch we live in today, beginning about 11,700 years ago after the last Ice Age ended. Scientists divided it into three parts - the Greenlandian, the Northgrippian, and finally, the Meghalayan.

Each was supposed to mark a major global climate event....