Uintan

{{Infobox geologic timespan

| name = Uintan

| color = Uintan

| time_start = 46.2

| time_end = 42.0

| image_map =

| caption_map =

| image_outcrop =

| caption_outcrop =

| image_art =

| caption_art =

| timeline = Paleogene

| formerly_part_of = Tertiary Period/System

| partially_contained_in =

| partially_contains =

| name_formality = Formal

| name_accept_date =

| alternate_spellings =

| synonym1 =

| synonym1_coined =

| synonym2 =

| synonym2_coined =

| synonym3 =

| synonym3_coined =

| nicknames =

| former_names =

| proposed_names =

| celestial_body = earth

| usage = Global (ICS)

| timescales_used = ICS Time Scale

| formerly_used_by =

| not_used_by =

| chrono_unit = Age

| strat_unit = Stage

| proposed_by =

| type_section =

| timespan_formality = Formal

| upper_def_candidates = Calcareous nannofossil near LAD of the Haptophyte Reticulofenestra reticulata

| upper_gssp_candidates = Contessa highway section, Gubbio, Central Apennines, Italy

| o2 =

| co2 =

| temp =

| sea_level =

}}

The Uintan North American Stage is the North American faunal stage, typically set from 46,200,000 to 42,000,000 years before present lasting 4.2 million years.[https://web.archive.org/web/20071029224651/http://paleodb.org/cgi-bin/bridge.pl?action=displayInterval&interval_no=229 Paleobiology Database, Uintan] The Uintan Stage is a key part of the North American Land Mammal Age. In the Uinta Basin, a thriving subtropical ecosystem was formed at around 46.0 million years ago. It falls within the Eocene epoch, preceded by the Bridgerian and followed by the Duchesnean NALMA stages.{{Cite web |title=GeoWhen Database - Uintan |url=https://timescalefoundation.org/resources/geowhen/stages/Uintan.html |access-date=2025-06-01 |website=timescalefoundation.org}} The Uinta Formation is a key piece of this geologic stage. Mammalian sabretooths evolved and became dominant predators in the now-Western United States. These included Apataelurus, Diegoaelurus, and Machaeroides.{{Cite journal |last=Zack |first=Shawn P. |date=2019-11-22 |title=The first North American Propterodon (Hyaenodonta: Hyaenodontidae), a new species from the late Uintan of Utah |url=https://peerj.com/articles/8136 |journal=PeerJ |language=en |volume=7 |pages=e8136 |doi=10.7717/peerj.8136 |doi-access=free |issn=2167-8359|hdl=10150/636415 |hdl-access=free }}{{Cite journal |last1=County~tom@tskelly.gardnerville.nv.us |first1=Thomas S. Kelly~Natural History Museum of Los Angeles |last2=History~pmurphey@sdnhm.org |first2=Paul C. Murphey~San Diego Museum of Natural |date=2016-07-14 |title=Mammals from the earliest Uintan (middle Eocene) Turtle Bluff Member, Bridger Formation, southwestern Wyoming, Part 1: Primates and Rodentia |url=https://palaeo-electronica.org/content/2016/1518-earliest-uintan-mammals |access-date=2025-06-01 |journal=Palaeontologia Electronica |doi=10.26879/586 |language=en|doi-access=free }}