Heliobatis radians Green River Formation

Fossil Butte National Monument is a

United States National Monument In the United States, a national monument is a protected area that can be created from any land owned or controlled by the federal government by proclamation of the President of the United States or an act of Congress. National monuments pr ...

managed by the

National Park Service The National Park Service (NPS) is an agency of the United States federal government within the U.S. Department of the Interior that manages all national parks, most national monuments, and other natural, historical, and recreational propert ...

, located west of

Kemmerer, Wyoming Kemmerer is the largest city in and the county seat of Lincoln County, Wyoming, United States. Its population was 2,656 at the 2010 census. History Explorer John C. Frémont discovered coal in the area during his second expedition in 1843. The ...

, United States. It centers on an assemblage of

Eocene Epoch The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', "daw ...

(56 to 34 million years ago) animal and plant fossils associated with Fossil Lake—the smallest lake of the three great lakes which were then present in what are now

Wyoming Wyoming () is a state in the 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 southwest, and Colorado to the s ...

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...

, and

Colorado Colorado (, other variants) is a state in the Mountain states, Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the wes ...

. The other two lakes were Lake Gosiute and Lake Uinta. Fossil Butte National Monument was established as a national monument on October 23, 1972. Fossil Butte National Monument preserves the best paleontological record of Cenozoic aquatic communities in North America and possibly the world, within the 50-million-year-old

Green River Formation The Green River Formation is an Eocene geologic formation that records the sedimentation in a group of intermountain lakes in three basins along the present-day Green River in Colorado, Wyoming, and Utah. The sediments are deposited in very fine ...

— the ancient lake bed. Fossils preserved include fish, alligators, bats, turtles, a dog-sized horse, insects, and many other species of plants and animals — suggest that the region was a low, subtropical, freshwater basin when the sediments accumulated, over about a 2 million-year period.

Geologic formations

During the

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...

this portion of

was a

sub-tropical The subtropical zones or subtropics are geographical and climate zones to the north and south of the tropics. Geographically part of the temperate zones of both hemispheres, they cover the middle latitudes from to approximately 35° north a ...

lake ecosystem. The Green River Lake System contained three ancient lakes, Fossil Lake, Lake Gosiute, and Lake Uinta. These lakes covered parts of southwest

, northeast

and northwestern

. Fossil Butte is a remnant of the deposits from Fossil Lake. Fossil Lake was long from north to south and wide. Over the two million years that it existed, the lake varied in length and width. Fossil Buttes National Monument contains only 13 square miles () of the 900-square-mile () ancient lake. The ancient lake sediments that form the primary fossil digs is referred to as the

. In addition to this fossil-bearing strata, a large portion of the

Wasatch Formation The Wasatch Formation (Tw)Shroba & Scott, 2001, p.3 is an extensive highly fossiliferous geologic formation stretching across several basins in Idaho, Montana Wyoming, Utah and western Colorado. When the fossils were discovered, miners dug them up to sell to collectors. In particular, Lee Craig sold fossils from 1897 to 1937. Commercial fossil collecting is not allowed within the National Monument, but numerous quarries on private land nearby continue to produce extraordinary fossil specimens, both for museums and for private collectors.

Exhibits

The Fossil Butte National Monument Visitor Center features over 80 fossils and fossil casts on exhibit, including fish, a crocodile, turtle, bats, birds, insects and plants. A 13-minute video is shown about the fossils found at the site and what scientists have learned. Interactive exhibits let visitors create fossil rubbings to take home, and a computer program discusses fossils, geology and the current natural history of the monument.

Activities

During the summer, lab personnel prepare fossils in public. Summer activities also include ranger programs, hikes, paleontology and geology talks, and participation in fossil quarry collections for the park. A Junior Ranger program can be completed by children aged 5–12 (with exercises scaled to the child's age) in 3–4 hours. A highlight is hiking 3/4 mile up the butte to the dig, where interns from the

Geological Society of America The Geological Society of America (GSA) is a nonprofit organization dedicated to the advancement of the geosciences. History The society was founded in Ithaca, New York, in 1888 by Alexander Winchell, John J. Stevenson, Charles H. Hitch ...

talk about their excavation and let children help them flake apart sedimentary deposits to discover fish fossils and

coprolite A coprolite (also known as a coprolith) is fossilized feces. Coprolites are classified as trace fossils as opposed to body fossils, as they give evidence for the animal's behaviour (in this case, diet) rather than morphology. The name is de ...

List of fossil species recovered at Fossil Butte National Monument

''Fish:'' *'' Asterotrygon'' spp, an extinct stingray *'' Diplomystus dentatus,'' an extinct

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or h ...

*''

Knightia ''Knightia'' is an extinct genus of clupeid bony fish that lived in the freshwater lakes and rivers of North America and Asia during the Eocene epoch. The genus was erected by David Starr Jordan in 1907, in honor of the late University of Wyom ...

'' spp, an extinct fish related to herring and

sardines "Sardine" and "pilchard" are common names for various species of small, oily forage fish in the herring family Clupeidae. The term "sardine" was first used in English during the early 15th century, a folk etymology says it comes from the Ital ...

*Seven extinct species of

perch Perch is a common name for fish of the genus ''Perca'', freshwater gamefish belonging to the family Percidae. The perch, of which three species occur in different geographical areas, lend their name to a large order of vertebrates: the Per ...

*'' Heliobatis radians'', an extinct stingray *''

Notogoneus ''Notogoneus'' is an extinct genus of prehistoric ray-finned fish. A trace fossil attributed to ''Notogoneus osculus'' has been found in the Green River Formation. See also *Prehistoric fish The evolution of fish began about 530 million ...

'' spp, an extinct bottom-feeding fish *'' Crossopholis magnicaudatus''
Commons
, a 1-meter (40 inches) long predatory

paddlefish Paddlefish (family Polyodontidae) are a family of ray-finned fish belonging to order Acipenseriformes, and one of two living groups of the order alongside sturgeons (Acipenseridae). They are distinguished from other fish by their titular elongla ...

*''Asineops squamifrons'', called 'mystery fish'- allocated its own family ''Asineopidae'' *Two extinct species of the family Osteoglossidae *'' Amphiplaga brachyptera,'' an extinct

freshwater fish Freshwater fish are those that spend some or all of their lives in fresh water, such as rivers and lakes, with a salinity of less than 1.05%. These environments differ from marine conditions in many ways, especially the difference in levels of ...

*Two extinct species of the genus ''

Hiodon Hiodontidae, commonly called mooneyes, is a family of ray-finned fish with a single included genus ''Hiodon''. The genus comprise two living species native to North America and three to five extinct species recorded from Paleocene to Eocene age ...

'' ''Amphibians:'' * '' Aleoamphiuma tetradactylum'', an extinct omnivorous salamander * '' Aerugoamnis paulus'', an extinct frog ''Mammals:'' *''

Coryphodon ''Coryphodon'' (from Greek κορῦφὴ, "point", and ὀδοὺς, "tooth", meaning ''peaked tooth'', referring to "the development of the angles of the ridges into points n the molars") is an extinct genus of pantodonts of the family Corypho ...

'' *'' Onychonycteris finneyi'' and '' Icaronycteris index'', bats *'' Heptodon'', an extinct

tapir Tapirs ( ) are large, herbivorous mammals belonging to the family Tapiridae. They are similar in shape to a pig, with a short, prehensile nose trunk. Tapirs inhabit jungle and forest regions of South and Central America, with one species inh ...

*'' Apatemys chardini'', a tree-dwelling mammal similar to the

lemur Lemurs ( ) (from Latin ''lemures'' – ghosts or spirits) are wet-nosed primates of the superfamily Lemuroidea (), divided into 8 families and consisting of 15 genera and around 100 existing species. They are endemic to the island of Madagas ...

*'' Protorohippus'', an early horse-like mammal *'' Palaeosinopa didelphoides'', an otter-like carnivore *'' Hyopsodus wortmani'' 'tube sheep', a small omnivore *'' L. popoagicum'', an extinct

odd-toed ungulate Odd-toed ungulates, mammals which constitute the taxonomic order Perissodactyla (, ), are animals—ungulates—who have reduced the weight-bearing toes to three (rhinoceroses and tapirs, with tapirs still using four toes on the front legs) o ...

''Birds:'' *

Frigate bird Frigatebirds are a family of seabirds called Fregatidae which are found across all tropical and subtropical oceans. The five extant species are classified in a single genus, ''Fregata''. All have predominantly black plumage, long, deeply forked ...

s *'' Pseudocrypturus cercanaxius'', an extinct shoreline bird *'' Gallinuloides wyomingesis'', an extinct land fowl *'' Primobucco mcgrewi'', an extinct roller bird *Four extinct species of

parrot Parrots, also known as psittacines (), are birds of the roughly 398 species in 92 genera comprising the order Psittaciformes (), found mostly in tropical and subtropical regions. The order is subdivided into three superfamilies: the Psittacoide ...

- '' Cyrillavis coldurnorum, Cyrillavis olsoni, Avolatavis tenens'' and '' Tynskya eocaena'' ''Reptiles:'' *''

Afairiguana ''Afairiguana avius'' is an extinct iguanid lizard known from a nearly complete and articulated skeleton discovered in rocks of the Early Eocene-aged Green River Formation of Wyoming, United States. As of the initial description, the skeleton rep ...

'', an extinct anole *'' Boavus idelmani'', a small extinct snake *'' Bahndwivici, Afairiguana avius'' and '' Bahndwivici ammoskius'', extinct lizards *'' Baptemys wyomingenis'', an extinct river turtle *'' Echmatemys wyomingensis'', an extinct pond turtle *''

Borealosuchus wilsoni ''Borealosuchus'' (meaning "boreal crocodile") is an extinct genus of crocodyliforms that lived from the Late Cretaceous to the Eocene in North America. It was named by Chris Brochu in 1997 for several species that had been assigned to '' Leidyo ...

and Tsoabichi greenriverenis'', extinct crocodiles *Three species of soft-shell turtles- '' Apalone heteroglypta, Axestemys byssinus'' and '' Hummelichelys guttata'' *

Baenidae Baenidae is an extinct family of paracryptodiran turtles known from the Early Cretaceous to Eocene of North America. While during the Early Cretaceous they are found across North America, during the Late Cretaceous they are only found in Laram ...

, turtle ''Plants:'' *

Palm tree The Arecaceae is a family of perennial flowering plants in the monocot order Arecales. Their growth form can be climbers, shrubs, tree-like and stemless plants, all commonly known as palms. Those having a tree-like form are called palm ...

s *

Cattails ''Typha'' is a genus of about 30 species of monocotyledonous flowering plants in the family Typhaceae. These plants have a variety of common names, in British English as bulrush or reedmace, in American English as reed, cattail, or punks, in ...

*'' Gyrocarpus'' spp *''Lagokarpos Lacustris,'' a type of distinct 'winged fruit' plant ''Lagokarpos'' found in lake deposits *'' Ailanthus confucii'' *''

Platycerium ''Platycerium'' is a genus of about 18 fern species in the polypod family, Polypodiaceae. Ferns in this genus are widely known as staghorn or elkhorn ferns due to their uniquely shaped fronds. This genus is epiphytic and is native to tropical and ...

'', a staghorn

fern A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes exce ...

*'' Salvinia preauriculata'', a water fern *'' Lygodium kaulfussi'' 'climbing fern' *''

Nelumbo ''Nelumbo'' is a genus of aquatic plants with large, showy flowers. Members are commonly called lotus, though the name is also applied to various other plants and plant groups, including the unrelated genus '' Lotus''. Members outwardly resemb ...

'' spp *'' Chaneya tenuis''; a genus of uncertain affinities * Birthwort (species unknown) *

Soapberry Soapberry is a common name for several plants and may refer to: * Plants in the genus ''Sapindus'', native to warm temperate to tropical regions in both the Old World and the New World. The berries of these plants contain a natural, low-sudsing de ...

*Species similar to a

walnut A walnut is the edible seed of a drupe of any tree of the genus ''Juglans'' (family Juglandaceae), particularly the Persian or English walnut, '' Juglans regia''. Although culinarily considered a "nut" and used as such, it is not a true ...

''Arthropods:'' * '' Bechleja rostrata'', an extinct species of shrimp * '' Procambarus primaevus'', an extinct species of crayfish * Three unidentified species of

spider Spiders ( order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species ...

Dragonflies A dragonfly is a flying insect belonging to the infraorder Anisoptera below the order Odonata. About 3,000 extant species of true dragonfly are known. Most are tropical, with fewer species in temperate regions. Loss of wetland habitat threa ...

* Damselflies *

Crickets Crickets are orthopteran insects which are related to bush crickets, and, more distantly, to grasshoppers. In older literature, such as Imms,Imms AD, rev. Richards OW & Davies RG (1970) ''A General Textbook of Entomology'' 9th Ed. Methuen 8 ...

* Other insects including bees and

ant Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of ...

s Primary source:Green River Formation Fossils
at Fossil Butte

Gallery

File:Knightia eocaena FBNM.JPG, '' Knightia eocaena'' fish, about long. ''Knightia'' is the most commonly excavated fossil fish in the world. File:Priscacara liops Green River Formation.jpg, '' Cockerellites liops'' from Fossil Lake. An extinct

. About long. File:Fossil Sabalites sp palm.jpg, Fossil ''Sabalites'' sp. palmetto frond, about long. File:Notogoneus osculus.png, ''

Notogoneus osculus ''Notogoneus'' is an extinct genus of prehistoric ray-finned fish. A trace fossil attributed to ''Notogoneus osculus'' has been found in the Green River Formation. See also *Prehistoric fish The evolution of fish began about 530 million ...

,'' a bottom-dwelling fish from Fossil Lake. File:Fossil bird Field Museum.jpg, An unidentified fossil bird from FBNM, in the collections of the Field Museum File:Buprestidae beetle, FBNM.jpg, A well-preserved Buprestidae beetle ( long) from the FBNM collections. Other beetles, flies and '' Hemiptera'' bugs have also been found in the Fossil Lake sediments.

References

External links

National Park Service: official Fossil Butte National Monument website

from FBNM * ttps://web.archive.org/web/20080906194457/http://3dparks.wr.usgs.gov/2006/fossilbutte/html2/fossil06.htm Photo tour of FBNM from

USGS The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, a ...

Paleontology of Green River fossils
from

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant u ...

Geologic travel guide
from

American Geological Institute The American Geosciences Institute (AGI) is a nonprofit federation of about 50 geoscientific and professional organizations that represents geologists, geophysicists, and other earth scientists. The organization was founded in 1948. The name of ...

{{Authority control National Park Service National Monuments in Wyoming Eocene Fossil parks in the United States Protected areas of Lincoln County, Wyoming Natural history museums in Wyoming Museums in Lincoln County, Wyoming Protected areas established in 1972 Paleontology in Wyoming Paleontological protected areas in the United States 1972 establishments in Wyoming 1972 in paleontology