The Puercan North American Stage on the

geologic timescale The geologic time scale, or geological time scale, (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochronol ...

is the North American

faunal stage In chronostratigraphy, a stage is a succession of rock strata laid down in a single age on the geologic timescale, which usually represents millions of years of deposition. A given stage of rock and the corresponding age of time will by conventi ...

according to the

North American Land Mammal Ages The North American land mammal ages (NALMA) establishes a geologic timescale for North American fauna beginning during the Late Cretaceous and continuing through to the present. These periods are referred to as ages or intervals (or stages when ref ...

chronology (NALMA), spanning the interval from 66,000,000 to 63,300,000 years BP lasting . It is usually considered to be within the

Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), E ...

. The Puercan directly follows the

Lancian The Lancian was a North American faunal stage of the Late Cretaceous. It was the final stage of the Cretaceous period in North America, lasting from approximately 70.6 to 66 million years ago. Geology Terrestrial sedimentary strata from the Judit ...

NALMA, with the K-Pg boundary and K-Pg mass extinction at 66 MYA representing the boundary between the two. The Puercan is followed by the

Torrejonian The Torrejonian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 63,300,000 to 60,200,000 years BP lasting . It is usually ...

NALMA stage. Puercan age fossils, from the

Great Divide Basin The Great Divide Basin or Great Divide Closed Basin is an area of land in the Red Desert of Wyoming where none of the water falling as rain to the ground drains into any ocean, directly or indirectly. It is thus an endorheic basin, one of severa ...

Wyoming Wyoming () is a U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the south ...

, include three newly identified

condylarth Condylarthra is an informal group – previously considered an order – of extinct placental mammals, known primarily from the Paleocene and Eocene epochs. They are considered early, primitive ungulates. It is now largely considered to be a wast ...

members of the

Periptychidae Periptychidae is a family of Paleocene placental mammals, known definitively only from North America. The family is part of a radiation of early herbivorous and omnivorous mammals formerly classified in the extinct order " Condylarthra", which ...

; '' Miniconus jeanninae, Conacodon hettingeri, Beornus honeyi''

Substages

The Puercan is considered to contain the following substages: *Pu3: Lower boundary(?) source of the base of the Puercan (approximate). *Pu2: Lower boundary source of the base of Puercan (approximate) and upper boundary source of the base of the Torrejonian (approximate). *Pu1: Lower boundary source of the base of the Puercan (approximate) and upper boundary source of the base of the Torrejonian (approximate).

References

Paleocene life Paleocene animals of North America {{geochronology-stub