The Asian land mammal ages, acronym ALMA, establish a
geologic timescale for
prehistoric Asian
fauna beginning 58.7
Mya during the
Paleogene and continuing through to the
Miocene (
Aquitanian) (23.03 Ma). These periods are referred to as ages, stages, or intervals and were established using geographic place names where fossil materials where obtained.
The basic unit of measure is the first/last boundary statement. This shows that the first appearance event of one taxon is known to predate the last appearance event of another. If two
taxa are found in the same
fossilquarry or at the same
stratigraphic horizon, then their age-range zones overlap.