Where dinosaur fossils are found

Hell Creek Formation · USA -- Montana, North & South Dakota, Wyoming

The single most productive dinosaur-bearing formation in North America, and the rock that preserves the very end of the Age of Dinosaurs. Most of the record-setting fossil auction sales -- Sue, Stan, and Gus -- all came out of the Hell Creek.

Collecting: Isolated teeth and bone fragments are common on legal, permitted private land; articulated skeletons are rare and scientifically significant.

Triceratops specimen, Royal Tyrrell Museum -- © MathKnight, CC BY-SA 4.0, via Wikimedia Commons

Morrison Formation · USA -- Colorado, Utah, Wyoming, Montana, and neighboring states

The formation behind most of the giant sauropods and plated/armored dinosaurs that defined 19th- and 20th-century dinosaur discovery in North America, including the original Bone Wars quarries.

Collecting: Large sauropod bone is the most commonly recovered material; Dinosaur National Monument (Utah) preserves an in-situ quarry wall visitors can view without collecting.

Diplodocus carnegii cast, Museum für Naturkunde Berlin -- Photo by Dosseman, CC BY-SA 4.0, via Wikimedia Commons

Djadochta & Nemegt Formations · Mongolia and northern China

Extremely arid conditions in the Gobi produce some of the best three-dimensionally preserved dinosaur skeletons anywhere, including specimens caught in the act of dying -- the 'Fighting Dinosaurs' block (a Velociraptor and Protoceratops locked together) is the most famous example.

Collecting: Fossil collecting and export are tightly regulated by Mongolian law; nearly all scientifically significant Gobi material is collected under formal joint research expeditions, not private hunting.

Velociraptor skeletal mount, Wyoming Dinosaur Center -- CC BY 2.0, via Wikimedia Commons

Yixian & Jiufotang Formations (Jehol Biota) · China -- Liaoning Province

Fine-grained volcanic ash preserved entire ecosystems in exceptional detail, including soft tissue -- this is the source of nearly all direct fossil evidence of feathers on non-avian dinosaurs, which reshaped the modern understanding of the dinosaur-bird relationship.

Collecting: A commercial fossil trade in Liaoning material exists, but export of significant vertebrate fossils from China is restricted by law; buyers should treat provenance documentation here as essential, not optional.

Sinosauropteryx prima fossil plate, Houston Museum of Natural Science -- via Wikimedia Commons

Candeleros & Huincul Formations (Neuquen Group) · Argentina

Home to the largest land animals ever confidently described, alongside the theropods that hunted them -- this region has produced some of the largest sauropod and carcharodontosaurid skeletons known.

Collecting: Fossils are the property of the Argentine state; excavation is carried out by permitted academic institutions, and most major finds end up in Argentine museums such as the Museo Municipal Carmen Funes.

Giganotosaurus mounted skull -- via Wikimedia Commons

Wessex & Wealden Formations · United Kingdom -- Isle of Wight, and the Weald (Surrey, Sussex, Kent)

The Isle of Wight's eroding cliffs are Europe's richest dinosaur coastline, and the source of the very first dinosaur ever scientifically named -- Iguanodon, described in 1825 from Wealden material found on the mainland.

Collecting: Beach collecting of loose material washed from the cliffs is a popular, legal hobby along much of the Isle of Wight coast; extracting fossils directly from the cliff face is discouraged for safety and conservation reasons.

Historic 1882 Iguanodon bernissartensis mount, Brussels -- Photo by Aimé Rutot, public domain, via Wikimedia Commons

Kem Kem Group · Morocco

A dense cluster of large predatory dinosaurs in one place -- Spinosaurus, Carcharodontosaurus, and Deltadromeus all hunted the same river system, an unusual concentration of giant theropods that's still debated among paleontologists as the 'Kem Kem puzzle.'

Collecting: An active commercial trade in Kem Kem teeth and bone exists and supplies much of the loose 'Spinosaurus tooth' material sold internationally; export from Morocco is regulated, so provenance paperwork matters here as much as anywhere on this list.

Spinosaurus mounted cast, Field Museum -- CC BY-SA 4.0, via Wikimedia Commons

Tendaguru Formation · Tanzania

German expeditions excavated this site from 1909-1913 in one of the largest fossil-dig operations of its era, shipping crated bone by porter caravan to the coast; the giant sauropod mount mistakenly long labeled 'Brachiosaurus' in Berlin is Tendaguru material now recognized as its own genus, Giraffatitan.

Collecting: Tendaguru's giant sauropods and stegosaurs are a close African counterpart to North America's Morrison Formation fauna from roughly the same period; active excavation today is led by Tanzanian and partner-institution research teams, not commercial collectors.

Giraffatitan brancai mount, Museum für Naturkunde Berlin -- CC BY-SA 4.0, via Wikimedia Commons

Winton Formation · Australia -- Queensland

Australia's richest dinosaur formation, and the source of most named Australian dinosaur genera, including a genuine dinosaur stampede trackway site at Lark Quarry, one of the few of its kind anywhere in the world.

Collecting: Much of the significant material comes from sheep and cattle stations across outback Queensland, often reported by station owners; Australian Age of Dinosaurs (near Winton) prepares and houses much of this material and runs public fossil-preparation visits.

Lameta Formation · India -- Madhya Pradesh, Gujarat, Maharashtra

India's main dinosaur-bearing formation, notable for extensive in-situ sauropod nesting grounds -- dense clusters of fossilized titanosaur eggs, some still exposed in the original limestone bedding, alongside the abelisaurid predators that likely hunted the nesting colonies.

Collecting: Collecting is tightly restricted -- vertebrate fossils are protected under Indian antiquities and wildlife law, and known egg and bone sites are managed by the Geological Survey of India and state governments, not open to private collecting.