Tiffanian

The Tiffanian is a North American land mammal age (NALMA) within the Paleocene epoch. It follows the Torrejonian NALMA and precedes the Clarkforkian NALMA. It is generally considered to span from approximately 59.2 to 56.8 million years ago. The Tiffanian is defined by its characteristic fossil mammal assemblages found in terrestrial deposits across western North America.

The Tiffanian NALMA is characterized by the appearance and diversification of various mammalian groups, reflecting significant evolutionary changes following the Cretaceous-Paleogene extinction event. Key indicator taxa often used to define and correlate Tiffanian faunas include specific genera and species of primates, multituberculates, and condylarths (early ungulates). The mammalian fauna is indicative of a generally warm and humid climate, though potentially trending towards cooler conditions compared to the preceding Torrejonian.

Stratigraphically, Tiffanian-age rocks are found in numerous sedimentary basins across the western interior of North America, including areas in Wyoming, Montana, Colorado, and Saskatchewan. These rocks typically consist of sandstones, shales, and coal deposits that accumulated in fluvial and lacustrine environments. Detailed biostratigraphic studies of fossil mammals found in these rocks allow for the subdivision of the Tiffanian into finer zones, providing a framework for understanding the timing and tempo of mammalian evolution during this interval of the Paleocene.