Hannold Hill Formation
Stratigraphic range: Wasatchian 55.8–50 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Unit of	Tornillo Group
Location
Coordinates	29°24′N 103°06′W / 29.4°N 103.1°W / 29.4; -103.1
Approximate paleocoordinates	33°42′N 89°00′W / 33.7°N 89.0°W / 33.7; -89.0
Region	Texas
Country	United States
Type section
Named for	Hannold Hill
Hannold Hill Formation (the United States) Show map of the United States Hannold Hill Formation (Texas) Show map of Texas

The Hannold Hill Formation is an Early Eocene (Wasatchian) geologic unit in the western United States.^[1] It preserves the fossilized remains of the ray Myliobatis and gar.^[2]

The following fossils have been reported from the formation:^[1]

Glires

• Paramys excavatus^[3]

Pantodonta

• Caenolambda jepseni^[3]
• Coryphodon armatus^[4]
• Coryphodon sp.^[5]

Perissodactyla

• Hyracotherium vasacciense
• Minippus index^[4]

Placentalia

• Hyopsodus cf. wortmani^[3]
• Hyopsodus sp.^[4]
• Phenacodus sp.^[4]

Primates

• Phenacolemurinae indet.^[4]

Wasatchian correlations in North America

Formation	Wasatch	DeBeque	Claron	Indian Meadows	Pass Peak	Tatman	Willwood	Golden Valley	Coldwater	Allenby	Kamloops	Ootsa Lake	Margaret	Nanjemoy	Hatchetigbee	Tetas de Cabra	Hannold Hill	Coalmont	Cuchara	Galisteo	San Jose	Ypresian (IUCS) • Itaboraian (SALMA) Bumbanian (ALMA) • Mangaorapan (NZ)
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	Raton	Galisteo	San Juan	Hannold Hill Formation (North America)
Country	United States								Canada					United States		Mexico	United States
Copelemur
Coryphodon
Diacodexis
Homogalax
Oxyaena
Paramys
Primates
Birds
Reptiles
Fish
Insects
Flora
Environments	Alluvial-fluvio-lacustrine	Fluvial				Fluvial	Fluvio-lacustrine	Fluvial	Lacustrine		Fluvio-lacustrine		Deltaic-paludal	Shallow marine		Fluvial	Shallow marine	Fluvial		Fluvial		Wasatchian volcanoclastics Wasatchian fauna Wasatchian flora
Volcanic	Yes	No							Yes	No	Yes	No	Yes	No						Yes	No

• Hunt, ReBecca K., Vincent L. Santucci and Jason Kenworthy. 2006. "A preliminary inventory of fossil fish from National Park Service units." in S.G. Lucas, J.A. Spielmann, P.M. Hester, J.P. Kenworthy, and V.L. Santucci (ed.s), Fossils from Federal Lands. New Mexico Museum of Natural History and Science Bulletin 34, pp. 63–69
• Alroy, J (2002), Synonymies and reidentifications of North American fossil mammals
• Lucas, S. G (1989), "Coryphodon (Mammalia, Pantodonta) from the Hannold Hill Formation, Eocene of Trans-Pecos Texas", Pearce-Sellards Series, 46
• J. A. Schiebout and Et al. 1987. Stratigraphy of the Cretaceous-Tertiary and Paleocene-Eocene Transition Rocks of Big Bend National Park, Texas . Journal of Geology 95
• J. A. Wilson. 1967. Early Tertiary mammals. In R. A. Maxwell, J. T. Lonsdale, R. T. Hazzard, & J. A. Wilson (eds.), Geology of Big Bend National Park, Brewster County, Texas. The University of Texas Publication 6711:157-169