PBDB Interval Range

18.5 - 12.5 Ma

International Chronostratigraphic Timescale			North American Mammal Subages/Zones	North American Land Mammal Ages
					1.4
Neogene	Pliocene	Piacenzian	Senecan/Rexroadian	Blancan	2.58
		Zanclean	Senecan/Rexroadian	Blancan	3.6
		Zanclean	Late Hemphillian/late Early Hemphillian/early Early Hemphillian	Hemphillian	4.7
	Miocene	Messinian			5.333
		Tortonian			7.246
		Tortonian	Late Clarendonian/Early Clarendonian	Clarendonian	9.4
		Serravallian	Late Clarendonian/Early Clarendonian	Clarendonian	11.63
		Serravallian	late Late Barstovian/early Late Barstovian/Early Barstovian	Barstovian	12.5
		Langhian			13.82
		Burdigalian			15.98
			Late Hemingfordian/Early Hemingfordian	Hemingfordian	16.3
			late Late Arikareean/early Late Arikareean/late Early Arikareean/early Early Arikareean/Harrisonian	Arikareean	18.5
		Aquitanian		Arikareean	20.45
					23.04 *
					23.1
					29.5