Earth:Wasatchian

Short description: North American faunal stage

The Wasatchian 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 55,400,000 to 50,300,000 years BP lasting 5.1 million years.^[1]

It is usually considered to be within the Eocene, more specifically the Early Eocene.

The Wasatchian is preceded by the Clarkforkian and followed by the Bridgerian NALMA stages.

Definition

The age is named after the Wasatch Formation, a highly fossiliferous stratigraphic unit stretching across six of the United States from Idaho and Montana in the north through Utah and Wyoming to Colorado and New Mexico in the south.

Substages

The Wasatchian is considered to contain the following substages:

Sandcouleean: shares lower boundary with the beginning of the Wasatchian age and shares upper boundary with the base of the Graybullian.
Graybullian: shares lower boundary with the end of the Sandcouleean subage and upper boundary with the base of the Lysitean.
Lysitean: shares lower boundary with the end of the Graybullian subage and upper boundary with the base of the Lostcabinian.
Lostcabinian: shares lower boundary with the end of the Lysitean subage and upper boundary with the beginning of the Bridgerian.

Wasatchian correlations

Wasatchian correlations in North America
Basin	Powder River Uinta Piceance Colorado Plateau Wind River Green River Bighorn	Piceance	Colorado Plateau	Wind River	Green River	Bighorn		Williston	Okanagan	Princeton	Buck Creek	Nechako	Sverdrup	Potomac	GoM	Laguna Salada	Rio Grande	North Park	Galisteo	San Juan	Wasatchian (North America)
Country	United States								Canada					United States		Mexico	United States
Copelemur	14px	14px					14px													14px
Coryphodon	14px	14px		14px			14px	14px					14px		14px		14px		14px	14px
Diacodexis	14px	14px			14px		14px	14px								14px				14px
Homogalax	14px	14px		14px			14px	14px						14px					14px
Oxyaena	14px	14px					14px									14px				14px
Paramys	14px	14px		14px	14px		14px	14px					14px				14px			14px
Primates	10px			10px			10px						10px				10px		10px	10px
Birds	10px								10px	10px			10px	10px
Reptiles	10px		10px					10px					10px	10px		10px				10px
Fish	10px		10px					10px		10px			10px	10px		10px
Insects								10px	10px	10px	10px	10px						10px
Flora	10px					10px	10px	10px	10px	10px				10px		10px		10px
Environments	Alluvial-fluvio-lacustrine	Fluvial				Fluvial	Fluvio-lacustrine	Fluvial	Lacustrine		Fluvio-lacustrine		Deltaic-paludal	Shallow marine		Fluvial	Shallow marine	Fluvial	Fluvial		Wasatchian volcanoclastics 8px Wasatchian fauna Wasatchian flora
Volcanic	Yes	No							Yes	No	Yes	No	Yes	No					Yes	No