Agate Fossil Beds National Monument is a U.S. National Monument near

Harrison, Nebraska Harrison is a village in Sioux County, Nebraska, Sioux County, Nebraska, United States. The population was 239 at the United States Census, 2020, 2020 census. It is the county seat of Sioux County. History Harrison was originally called Bowen, a ...

. The main features of the monument are a

valley A valley is an elongated low area often running between hills or mountains and typically containing a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams over ...

of the Niobrara River and the fossils found on Carnegie Hill and University Hill. The area largely consists of grass-covered

plain In geography, a plain, commonly known as flatland, is a flat expanse of land that generally does not change much in elevation, and is primarily treeless. Plains occur as lowlands along valleys or at the base of mountains, as coastal plains, and ...

s. Plants on the site include prairie sandreed,

blue grama ''Bouteloua gracilis'', the blue grama, is a long-lived, warm-season (C4 carbon fixation, C4) Perennial plant, perennial grass, native to North America. It is most commonly found from Alberta, Canada, east to Manitoba and south across the Rocky ...

, little bluestem and needle and thread grass, and the wildflowers

lupin ''Lupinus'', commonly known as lupin, lupine, or regionally bluebonnet, is a genus of plants in the legume family Fabaceae. The genus includes over 199 species, with centres of diversity in North and South America. Smaller centres occur in No ...

, spiderwort, western wallflower and

sunflower The common sunflower (''Helianthus annuus'') is a species of large annual forb of the daisy family Asteraceae. The common sunflower is harvested for its edible oily seeds, which are often eaten as a snack food. They are also used in the pr ...

History

Entering Agate Fossil Beds National Monument

Originally the Agate Springs Ranch, a working cattle ranch, was owned by Capt. James Cook. The monument's museum collection also contains more than 500 artifacts from the Cook Collection of

Plains Indians Plains Indians or Indigenous peoples of the Great Plains and Canadian Prairies are the Native American tribes and First Nations peoples who have historically lived on the Interior Plains (the Great Plains and Canadian Prairies) of North ...

artifacts. The national monument was authorized on June 5, 1965, but was not established until June 14, 1997. The Harold J. Cook Homestead (Bone Cabin Complex) was listed on the

National Register of Historic Places The National Register of Historic Places (NRHP) is the Federal government of the United States, United States federal government's official United States National Register of Historic Places listings, list of sites, buildings, structures, Hist ...

in 1977. Agate Fossil Beds is maintained by the

National Park Service The National Park Service (NPS) is an List of federal agencies in the United States, agency of the Federal government of the United States, United States federal government, within the US Department of the Interior. The service manages all List ...

Paleontology

The site is best known for a large number of well-preserved

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

s, many of which were found at dig sites on Carnegie and University Hills. Fossils from the Harrison Formation and Anderson Ranch Formation, which date to the

Arikareean The Arikareean 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 30,600,000 to 20,800,000 years BP, a period of . It is usuall ...

in the North American land mammal classification, about 20 to 16.3 million years ago, are among some of the best specimens of Miocene

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

s. Species found in Agate include: * ''

Merychippus ''Merychippus'' is an extinct proto-horse of the family Equidae that was endemic to North America during the Miocene, 15.97–5.33 million years ago. It had three toes on each foot and is the first horse known to have Grazing (behaviour), grazed ...

'' and '' Parahippus'', ancestors of the modern day horse. * '' Diceratherium'', two-horned

rhinoceros A rhinoceros ( ; ; ; : rhinoceros or rhinoceroses), commonly abbreviated to rhino, is a member of any of the five extant taxon, extant species (or numerous extinct species) of odd-toed ungulates (perissodactyls) in the family (biology), famil ...

. * '' Menoceras'', pony-sized

, the most common animal found in the fossil beds. * '' Daphoenodon'' and ''

Ysengrinia ''Ysengrinia'' is an extinct genus of carnivoran in the family Bear dog, Amphicyonidae, that lived during the Chattian, Late Oligocene to Early Miocene. Fossil remains have been discovered in Western Europe, the United States and possibly China. ...

'', two types of mid-sized bear dogs. * '' Promerycochoerus'', a semiaquatic hippo-like oreodont. * '' Daeodon'', the largest Entelodont (giant pig-like ungulate). * '' Stenomylus'', gazelle-like camelids. * '' Oxydactylus'', giraffe-like camelids. * '' Palaeocastor'', land beavers that dug large corkscrew-shaped burrows (''Daemonelix''). * '' Moropus'', a chalicothere which are relatives of rhinos and horses. * '' Merychyus'', a sheep-like oreodont. * '' Syndyoceras'', antelope-like mammal and extinct relatives of artiodactyls.

Gallery

References

External links

* Official NPS website
Agate Fossil Beds National Monument
{{authority control Federal lands in Nebraska National Park Service national monuments in Nebraska Cenozoic paleontological sites of North America Miocene paleontological sites Natural history of Nebraska Protected areas established in 1997 Dinosaur museums in the United States Natural history museums in Nebraska Museums in Sioux County, Nebraska Protected areas of Sioux County, Nebraska 1997 establishments in Nebraska Fossil parks in the United States Paleontology in Nebraska Paleontological protected areas in the United States 1997 in paleontology National Register of Historic Places in Sioux County, Nebraska

History

Paleontology

Gallery

See also

References

External links