San Marcos Formation From Wikipedia, the free encyclopedia Geologic formation in Mexico TypeFormationCountryMexicoSan Marcos FormationStratigraphic range: NeogeneTypeFormationLocationCountryMexico The San Marcos Formation is a geologic formation in Mexico. It preserves fossils dating back to the Neogene period. Earth sciences portalMexico portalPaleontology portal List of fossiliferous stratigraphic units in Mexico References Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Archived from the original on 19 August 2022. Retrieved 17 December 2021. This article about a specific stratigraphic formation in Mexico is a stub. You can help Wikipedia by expanding it.vte This article related to the Neogene period is a stub. You can help Wikipedia by expanding it.vte Related Articles