Apt is the etymological source of the Aptian, an age in the geologic timescale, a subdivision of the Early or Lower Cretaceous epoch or series and encompasses the time from 125.0 ± 1.0 Ma to 112.0 ± 1.0 Ma (million years ago), approximately.[3] The original type locality is in the vicinity of Apt. The Aptian was introduced in scientific literature by French palaeontologist Alcide d'Orbigny in 1840.