Article

Lagerstätten

photo of a fossil fish display
A fossil fish exhibit the in Fossil Butte National Monument's visitor center.

Introduction

Fossil Lagerstätten are exceptionally rich fossil deposits. The term was coined for these rare paleontological sites in 1970 and is derived from the German words for “storage” and “place.”

The two types of Lagerstätten are not exclusive to one another. A fossil deposit may have both a high number of fossils and contain fossils with exceptional preservation.

The National Park System contains four concentration Lagerstätten and four conservation Lagerstätten, with an additional conservation Lagerstätten located near Chickasaw National Recreation Area.

Three additional concentration Lagerstätten have been designated as National Natural Landmarks, one of which is also a conservation Lagerstätte. One conservation Lagerstätte is a National Historic Landmark.

Concentration Lagerstätten

Agate Fossil Beds National Monument

Photo of a display of fossil skeletons Photo of a display of fossil skeletons

Left image
Diorama in the Agate Fossil Beds National Monument Visitor Center using fossil casts to represent the scene at the dried up watering hole showing predators and scavengers (Daeodon and Daphoenodon) confronting three living and one dead Moropus.

The Lagerstätte in Agate Fossil Beds National Monument is the most important fossil site from the Early Miocene in North America. Great concentrations of bones of a wide variety of animals have been recovered from the location of watering holes where mass mortality events took place during periods of regional drought. Some specimens were articulated and nearly complete, but most are found in dense bonebeds.

The most common bones at University and Carnegie Hills, the main sites excavated in the early 1900s, were those of Menoceras (a small rhino). The jumble of disarticulated bones indicate that they had been extensively scavenged, including by the pig-like Daeodon and by Daphoenodon (bear dogs). Bones from about 20 Moropus, a distant relative of the horse with long front legs and short back legs and claw-like hooves, have also been recovered.

The Stenomylus Quarry is a separate fossil location in the park where more than 100 articulated specimens of Stenomylus, a diminutive gazelle-like camel, have been recovered.

University and Carnegie Hills are in the Anderson Ranch Formation and the Stenomylus Quarry is slightly older and is the Harrison Formation. The University and Carnegie Hills bone bed is in strata underneath a 19.2 million year old ash bed and the Stenomylus Quarry is slightly older and is the Harrison Formation below a 21-million-year-old ash bed.

Learn More

Dinosaur National Monument, Quarry Exhibit Hall

photo of a fossil quarry
Part of the concentration Lagerstätte in the bone bed exposed in the Quarry Exhibit Hall.
The bonebed exposed in the Quarry Exhibit Hall in Dinosaur National Monument is a concentration Lagerstätte. More than 1,500 dinosaur bones are exposed in situ in the exhibit from eleven different species, including Allosaurus, Apatosaurus, Camarasaurus, Diplodocus, and Stegosaurus.

The fossils are in the Quarry Sandstone Bed of the Brushy Basin Member of the Jurassic Morrison Formation, and are approximately 150 million years old. The great concentration of bones were deposited at a bend or on a sandbar along an ancient river bed where debris accumulated. The dinosaurs probably died at different times during periods of drought along the river shoreline or on the dried-out riverbed. Many of the skeletons are disarticulated and some bones have signs of scavenging like tooth marks.

Learn More

Hagerman Fossil Beds National Monument

Photo of a fossil horse skull
A skull of the Hagerman horse.

During the 1930s, five nearly complete skeletons, more than 100 skulls, and a large number of isolated bones of the Hagerman horse were excavated from the Horse Quarry in Hagerman Fossil Beds National Monument in Idaho. The Hagerman horse is more closely related to zebras than modern domesticated horses. It lived in North America during the Pliocene, between about 4 and 3 million years ago.

Individual horses recovered from the quarry range from yearlings to adults. It is thought that the animals either died while crossing a flooded river or during a period of drought.

The monument on the whole is one of the richest Pliocene fossil sites in the world, and has yielded more than 140 species to date.

Learn More

Waco Mammoth National Monument

Photo inside of mammoth dig shelter
The Dig Shelter at Waco Mammoth National Monument.
Waco Mammoth National Monument was established in 2015 to preserve the site of the nation’s first and only recorded evidence of a nursery herd of Pleistocene Columbian mammoths. The fossils of adult female and juvenile mammoths, many of which are nearly intact, allow for the study of the herd structure of mammoths. The nursery herd died about 67,000 years ago, most likely in a single event such as a catastrophic flood.The remains of more than 20 Columbian mammoths plus other Pleistocene fauna are present at the site in multiple stratigraphic levels, including bones left in situ in the Dig Shelter where the public can learn about these animals and the work of paleontologists.

Learn More

Conservation Lagerstätten

Buckhorn Asphalt Quarry (near Chickasaw National Recreation Area)

Photo of a fossil shell with colorful reflection
Fossil nautiloid shell with original aragonite and nacre.

Photo by James St. John.

The Buckhorn Asphalt Quarry in Oklahoma is located just outside of Chickasaw National Recreation Area. This site is known for the exceptional preservation of marine invertebrates whose shells retain their original aragonite and nacre (mother of pearl), which gives them an almost iridescent luster. Some shells even still have their color patterns. These fossils were preserved by heavy petroleum that seeped onto the seafloor either during or soon after deposition, preventing alteration to the shell material.

This Lagerstätte has the best preserved Paleozoic mollusk fauna in the world and contains the oldest known aragonite shells with nacreous luster. It is in the Pennsylvanian Deese Group and has fossils of more than 150 species, mostly of mollusks.

For further information

Florissant Fossil Beds National Monument

Photo of a fossil spider
Fossil spider from the Florissant Lagerstätte.

NPS photo.

Florissant Fossil Beds National Monument is both a conservation and concentration Lagerstätte, as the Florissant Formation contains both a great abundance and exceptional preservation of fossils. Fossils of insects, flowers, leaves, and other organisms are found in paper-thin shales that were deposited in the Eocene, about 35 to 34 million years ago. The park contains one of the world’s most species-rich assemblages of fossil plants and insects, with more than 1,850 species described.

The quality of the fossil preservation results from the unusual conditions of Lake Florissant, which was formed by the damming of a river system by a volcanic mudflow. The lake experienced blooms of microscopic diatoms after silica-rich volcanic ash was washed into it. After the diatoms died, their tests (shells) fell to the lake bottom, helping protect organisms and organic material from decay and sealing the thin shale layers containing the fossil impressions and compressions. Alternating shale and diatom layers record many such cycles of sedimentation and preservation in Lake Florissant.

Learn More

Fossil Butte National Monument

Photo of fossil fish on a rock slab
A group of schooling freshwater herring. Each fish is about 4 inches (10 cm) in length.
Like Florissant Fossil Beds National Monument, Fossil Butte National Monument contains both a conservation and concentration Lagerstätte. Also, Eocene in age, but slightly older at about 52 million years old, the Fossil Butte Member of the Green River Formation contains abundant fossils that show preservation of fine details. Fish are by far the most common type of fossil recovered from the park, but the Fossil Butte Member also contains fossils of plants, arthropods, mollusks, amphibians, reptiles, birds, and mammals.

The Fossil Butte Member was deposited in a lacustrine (lake) environment, but it had a different type of tectonic and geologic environment than that of Lake Florissant. Instead of a lake formed by volcanic activity, Fossil Lake was a shallow alkaline lake in a tectonic basin formed by downwarping of the crust in southwest Wyoming during the Laramide Orogeny. The chemistry of the lake played a key role in fossil preservation. A layer of oxygen-poor saltwater present near the lake bottom prevented decay and scavenging. Additionally, a microbial mat that encased dead organisms near the lake bottom also played an important role in creating the conditions that led to the exceptional preservation of Fossil Butte’s fossils.

Learn More

Glacier National Park

Photo of a fossil insect
Thief ant (Solenopsites abdita) queen. Kishenehn Formation. John S. LaPolla. US Natural History Museum, Washington D.C., United States; specimen USNM609597.

https://www.antweb.org/. Creative Commons Attribution 4.0 International.

The Kishenehn Formation, exposed along the Flathead River along the boundary of Glacier National Park, contains a conservation Lagerstätte that has been scientifically described more recently than the other Lagerstätten in national park sites. The Eocene Kishenehn Formation has long been known to contain fossil gastropods, but it has only been since the 1980s that the exceptionally well-preserved fossil insects have been scientifically known.

The insect fossils are mostly of flies, midges, mosquitoes, and water boatman, and are generally very small, usually no more than a few millimeters in length. They are found in oil shales as compressions and impressions, some with color preservations. The oil shales in the Kishenehn Formation are varves, which are very thin layers deposited annually, consisting of a organic-rich layer and a sediment-rich layer. The fossils are in the organic-rich layers, which are interpreted as resulting from spring-time algal blooms on the surface of shallow water or swampy areas. After insects became trapped in them, the growing mats protected them from decompositions before they sank and were buried by sediment.

John Day Fossil Beds National Monument

Photo of a fossil fern in a museum display
Fern frond, Clarno Nut Beds.

NPS photo.

Permineralized wood, seeds, and nuts as well as leaf impressions in the Clarno Nut Beds in John Day Fossils Beds National Monument make up one of the most diverse fossil floras in the world. This Lagerstätte is found in the Clarno Unit of the park. So far, more than 175 species of fruit and seeds have been described. Most species are flowering plants.

The Clarno Nut Beds have not only a great diversity of fossil species, but it also contains fossils of plant parts like seeds, fruits, and nuts that are rarely fossilized. The Clarno Formation contains much volcanic ash, providing a ready source of silica that helped preserve this record of semitropical forests that grew in central Oregon during the Eocene.

Learn More

National Natural Landmark and National Historic Landmark Lagerstätten

Ashfall Fossil Beds National Natural Landmark

Photo of a fossil quarry
Fossil exposed in the Hubbard Rhino Barn, Ashfall Fossil Beds State Historical Park.

Photo by James St. John.

Ashfall Fossil Beds State Historical Park is a National Natural Landmark that has Miocene fossils of rhinoceros, horses, camels, and other vertebrates that were killed by the effects of volcanic ash. A catastrophic volcanic eruption in Idaho 11.93 million years ago sent massive quantities of volcanic ash into the stratosphere where it traveled east and eventually encircled the globe. Approximately 12 inches (30 centimeters) of volcanic ash fell in northeastern Nebraska where Ashfall Fossil Beds is located.

Smaller animals were killed first by ash fallout, followed by successively larger animals with the skeletons of more than 100 rhinos present near the top of the deposit where they had congregated around a waterhole, perishing from the effects of ash inhalation.

More than 20 species of animals have been recovered from the site, and research is ongoing. The public can view exposed part of the bonebed in the Hubbard Rhino Barn.

Learn More

Mammoth Site Of Hot Springs National Natural Landmark

Photo of a mammoth fossil quarry
Mammoth Site at Hot Springs, South Dakota.

Wikimedia commons.

The Mammoth Site of Hot Springs in South Dakota is a National Natural Landmark that contains one of the largest concentration of mammoth bones in the United States. The site is at a prehistoric sinkhole that held a pond. Mammals that came to the pond were sometimes trapped due to the steep sides of the sinkhole and slippery slopes surrounding it. As the sinkhole slowly filled with sediment during the Pleistocene, the remains of at least 58 Columbian mammoths and 3 woolly mammoths were buried and preserved. Fossils of short-faced bears, shrub oxen, camels, wolves, and a number of small mammal species have also been recovered.

Learn More

Mazon Creek Fossil Beds National Historic Landmark

Photo of a worm fossil
Fossil worm. Mazon Creek Fossil Beds.

Photo by James St. John.

The Mazon Creek Fossil Beds of northern Illinois have been famous since the 19th century. Ironstone concretions preserve Pennsylvanian-age plants and animals, including soft parts and soft-bodied organisms that rarely fossilize, making this an outstanding conservation Lagerstätte. Part of the fossil beds are preserved as a National Historic Landmarks near Chicago, Illinois. The 10-acre site, located on private land, is an most important fossil localities for Pennsylvanian land plants and animals, and also has great importance in the history of paleontology in the United States.

Learn More

Rancho La Brea National Natural Landmark

Photo of a saber tooth cat skull
Smilodon sp. saber-toothed cat skull. La Brea Tar Pits.

Photo by James St. John.

The La Brea Tar Pits in Los Angeles is one of the most important Pleistocene fossil sites in the world. Oil seeping from the underground becomes asphalt when it reaches the Earth’s surface, and water or debris on top of asphalt deposits can hide it from view. Unsuspecting animals may then become mired while going from place to place or trying to drink from the water. Carnivores looking for an easy meal may become mired in turn. The tar seeps are still active today.

A wide diversity of fossils have been recovered from the site, which is both a conservation and concentration Lagerstätte. Species include saber-toothed cats, American lions, dire wolves, short-faced bears, Columbian mammoths, ground sloths, bison, birds, a host of smaller vertebrates, invertebrates, and plants. More than 3.5 million fossil specimens have been recovered from the site to date.

Learn More

Featured Parks


Last updated: October 7, 2024