Multiple trilobite fragments fossilized in the same rock
USNM_35225 and USNM_35227: Pictured are multiple trilobite fragments fossilized in the same rock. These are commonly known as hash beds. "Hash" is an indicator of a near-shore environment, where waves could hav... More
Multiple trilobite fragments fossilized in the same rock
USNM_35227 (pictured) and USNM_35225: Multiple trilobite fragments are fossilized in the same rock, these are commonly known as hash beds. "Hash" is an indicator of a near-shore environment, where waves could h... More
Yellowstone National Park, Trace fossil
Trace_Fossil_1: The photo shows burrows from possibly a trilobite. This sample was collected from the Park Shale in Yellowstone National Park during a field investigation on Mount Holmes back in 2001, in which... More
Fossilized second molar of a brontothere.
YELL_134174 (1) and (2): These pictures show the second molar of a brontothere that was discovered in Yellowstone National Park in the late 1990s. The tooth is the black-colored part, while the jaw bone is the ... More
Yellowstone National Park, Articulate brachiopods
YELL-92017 and YELL-92024 (pictured here): Both the inarticulate (YELL-92017) and articulate brachiopods (YELL-92024) existed about 520 million years ago. The inarticulate was collected from the Park Shale, whi... More
Yellowstone National Park, Agnostid trilobite
YELL-165705: A small, Agnostid trilobite (YELL-165705) head is shown here. How did these little arthropods survive 500 million years ago? From their lack of eyes and poorly suited swimming body, scientists infe... More
Yellowstone National Park, Hyolithes gallatinensis
USNM_35218 (pictured here) and YELL-92021: Hyolithes gallatinensis (USNM 35218) was collected from the Snowy Range Formation and is now reposited at the Smithsonian National Museum of Natural History. Hyolitha... More
Trilobite Ehmania walcotti, Yellowstone National Park
USNM_90667: During the Cambrian period and throughout the Paleozoic era, an inland sea occupied the Greater Yellowstone area, unlike its present landscape of mountains, geysers, and rivers. Fossils, like this t... More
National parks: Hyolithes - public domain image
YELL-92021 and USNM_35218: Hyolitha YELL-92021 (pictured) was collected from the Pilgrim Limestone and is housed with the Yellowstone collection. Hyolithes gallatinensis (USNM 35218) was collected from the Sn... More
Yellowstone National Park, Inarticulate brachiopods
YELL-92017 (pictured here) and YELL-92024: Both the inarticulate (YELL-92017) and articulate brachiopods (YELL-92024) existed about 520 million years ago. The inarticulate was collected from the Park Shale, wh... More
Yellowstone National Park, Ptychopariid trilobite
YELL-165706 (pictured) and YELL-165715: Many times when fossils are collected they are only casts of the specimen, such as these pictures of a few nearly complete Ptychopariid trilobite (YELL-165706 and YELL-16... More
Yellowstone National Park, Ptychopariid trilobite
YELL-165706 and YELL-165715 (pictured here): Many times when fossils are collected they are only casts of the specimen, such as the pictures above of a few nearly complete Ptychopariid trilobite (YELL-165706 an... More
Yellowstone National Park, Ptychopariid trilobite
YELL-92020: This head of a roughly 520 million year old Ptychopariid trilobite (YELL-92020) is one among many identified from the Pilgrim Limestone, on Mt. Holmes in Yellowstone National Park. Trilobite order P... More
Multiple trilobite fragments fossilized in the same rock
USNM_35236: Charles D. Walcott, renowned invertebrate paleontologists, identified trilobite specimen Solenopleura? weedi (USNM 35236) from the Upper Cambrian (~500 million years ago) Pilgrim limestone in northw... More
Multiple trilobite fragments fossilized in the same rock
USNM_61523: Dated about 500 million years old and collected from the Pilgrim Limestone in Yellowstone National Park, is type trilobite Tricrepicephalus yellowstonensis (USNM 61523). This particular species is j... More
trilobite Blountia polita, Yellowstone National Park
USNM_96488: The trilobite Blountia polita (USNM 96488) (pictured) was discovered in the Middle Cambrian (~520 million years ago), Pilgrim Formation of Yellowstone National Park. As trilobites continued to evolv... More
Pieces of petrified wood - Public Domain image, National Parks Gallery
YELL_92933: Due to events and processes associated with the volcanic activity now preserved as the Absoraka Supergroup, there is a great concentration of petrified forests and fossilized leaves within Yellows... More
Fossilized cones that were produced from trees during the Eocene Epoch...
YELL_94359: Rarely found within the park are fossilized cones that were produced from trees during the Eocene Epoch. Featured above is a well-preserved fossil cone of a Pinus macrolepis, collected in the Lamar ... More
Megan Norr - geologic resources division
2015 Mosaics in Science Program participant working on National Fossil Day materials at the Smithsonian National Museum of Natural History, Washington DC.