Serpukhovian
Table:
System	Subsystem/ Series	Stage	Age (Ma)

Permian	Cisuralian	Asselian	younger

Carboniferous	Pennsylvanian	Gzhelian	298.9	303.7

Kasimovian	303.7	307.0

Moscovian	307.0	315.2

Bashkirian	315.2	323.2

Mississippian	Serpukhovian	323.2	330.9

Visean	330.9	346.7

Tournaisian	346.7	358.9

Devonian	Late	Famennian	older

Subdivision of the Carboniferous system according to the ICS, as of 2017.

Having looked at the tabular data covering 'Serpukhovian' titled '', write a one-sentence description of the highlighted cells and return it as JSON: {"answer": "YOUR ANSWER"}.