01 / Coverage
Atlas-first, not exhaustive
The page highlights countries where current records, profiles, or hotspots give Fossil Atlas something specific to show.
Fossil Atlas country guide
Dinosaur fossils in the United States
The United States has some of the strongest current Fossil Atlas coverage. Hell Creek records support T. rex and Triceratops pages, while Morrison Formation records support the Stegosaurus profile and hotspot.
Country guide standard
How to read these country pages
Country pages are search entry points into Fossil Atlas, not national fossil encyclopedias.
02 / Evidence
Modern records, not ancient ranges
Country names describe where fossils are found or reported today. They do not reconstruct where animals lived in deep time.
03 / Next step
Follow the strongest link
Each guide should point you toward a specimen profile, hotspot, map layer, or expedition card you can actually use.
The formations
Hell Creek, Morrison, and beyond
America's dinosaur record spans the entire Mesozoic, but two formations dominate: the Morrison (Late Jurassic) and Hell Creek (latest Cretaceous). The Morrison covers a vast region and has produced thousands of dinosaur bones. Hell Creek preserves the last dinosaurs. Between them lie dozens of other important units: the Chinle Formation (Triassic, Arizona), the Kayenta Formation (Early Jurassic), and many more.
The Bone Wars
The birth of American dinosaur science
The Bone Wars made the American West central to dinosaur history, especially Morrison Formation localities in Colorado and Wyoming. Marsh and Cope's rivalry produced important names and collections, but this page keeps the history in service of the atlas: where the records are, what formations they belong to, and which current profile pages they support.
Fossil Atlas
US dinosaurs on the atlas
Fossil Atlas currently profiles several animals with strong US formation links: Tyrannosaurus rex, Triceratops, and Stegosaurus. The Hell Creek and Morrison hotspots map selected records from the current site dataset. As the dataset expands, additional US taxa and formations can receive individual profiles and hotspot pages.
Explore
US fossils on Fossil Atlas
New batch
Expanded US ecosystem links
Allosaurus
New Fossil Atlas profile connected to Morrison or latest-Cretaceous North America.
Diplodocus
New Fossil Atlas profile connected to Morrison or latest-Cretaceous North America.
Apatosaurus
New Fossil Atlas profile connected to Morrison or latest-Cretaceous North America.
Ankylosaurus
New Fossil Atlas profile connected to Morrison or latest-Cretaceous North America.
Edmontosaurus
New Fossil Atlas profile connected to Morrison or latest-Cretaceous North America.
Pachycephalosaurus
New Fossil Atlas profile connected to Morrison or latest-Cretaceous North America.
FAQ
Common questions about dinosaur fossils in the United States
Which US states have the most dinosaur fossils?
Many well-known US dinosaur records come from the Rocky Mountain and Great Plains regions, especially Montana, Wyoming, Utah, Colorado, North Dakota, South Dakota, and New Mexico. Fossil Atlas currently emphasizes Hell Creek records for T. rex and Triceratops and Morrison Formation records for Stegosaurus. Other US formations are important context but are not all represented as full pages yet.
What are the most famous US dinosaur formations?
The United States contains many well-known dinosaur-bearing formations. The strongest current Fossil Atlas links are Hell Creek for latest Cretaceous animals such as T. rex and Triceratops, and the Morrison Formation for Late Jurassic animals such as Stegosaurus. Other formations such as Lance, Two Medicine, Kayenta, and sites such as Dinosaur National Monument are useful future expansion targets.
How did the Bone Wars shape US dinosaur paleontology?
The Bone Wars — the fierce rivalry between Othniel Charles Marsh and Edward Drinker Cope in the 1870s–1890s — was fought largely in the Morrison Formation of Colorado and Wyoming. Their teams competed to discover and name new species, and although their methods were ruthless, the result was the discovery of many of America's most iconic dinosaurs: Stegosaurus, Allosaurus, Diplodocus, Apatosaurus, Triceratops, and more. The institutional collections they built — at Yale, the AMNH, the Smithsonian — remain cornerstones of vertebrate paleontology.
Where can I see dinosaur fossils in the US?
Major dinosaur exhibits can be seen at the American Museum of Natural History (New York), the Field Museum (Chicago, home of Sue the T. rex), the Smithsonian National Museum of Natural History (Washington, DC), the Natural History Museum of Los Angeles County, the Denver Museum of Nature & Science, the Museum of the Rockies (Bozeman, Montana), and the Carnegie Museum of Natural History (Pittsburgh). Dinosaur National Monument and various state parks allow visitors to see fossils in situ — still embedded in the rock where they were found.
Next step
Build an expedition card
Sources
Where this page gets its record context
Source links show where Fossil Atlas gets record and curation context. They do not make this page an exhaustive scientific bibliography.
- PBDB occurrence records for Tyrannosaurus rex
- PBDB occurrence records for Triceratops
- PBDB occurrence records for Stegosaurus
- PBDB records and stratigraphic metadata for selected fossil hotspots
- Fossil Atlas v1 manual curation and caveat review
- PBDB occurrence records for Allosaurus
- PBDB occurrence records for Diplodocus
- PBDB occurrence records for Apatosaurus
- PBDB occurrence records for Ankylosaurus
- PBDB occurrence records for Edmontosaurus
- PBDB occurrence records for Pachycephalosaurus
Caveat
What this page does not claim
This page provides a Fossil Atlas-oriented overview of US dinosaur fossil sites. It is not an exhaustive directory of every US fossil locality. The formation list emphasizes pages and records that currently connect to the atlas.
Fossil maps on linked pages show modern discovery locations for selected records. These are not ancient habitat or range maps.