Abstract Outcropping sedimentary deposits of the Potwar Plateau in northern Pakistan comprise the most complete record of Neogene Siwalik rocks and faunas to be found in the Indian subcontinent documenting an extraordinary record of terrestrial vertebrate fossils for the Miocene Epoch. The Potwar Plateau is a portion of the Siwalik Hills, the mountainous terrane of the outer Himalayas extending over 2000 km across the northern margin of the Indian subcontinent. Siwalik strata accumulated as a molassic sedimentary wedge shed southward with the erosion of the rising crust as it was uplifted via plate tectonics. The long Potwar record of numerous superposed assemblages of fossil vertebrates preserves a history spanning many millions of years, and constitutes a unique geoheritage resource for Asia and for the world. The record can be dated and interpreted with a high degree of precision rarely achieved in terrestrial settings. The Potwar Siwalik sediments document 18 million years of change in the subtropical ecosystem of South Asia, in which global to regional climate change directly impacted terrestrial palaeofloras and palaeofaunas, forcing coevolution of elements of the terrestrial food web, and with that the modernization of mammalian groups. The potential to trace coincidence of abiotic changes with evolution within lineages is unusual.