Around 41 US states have designated an official state fossil, making it one of the most widely-adopted state animal symbols. Unlike state birds or state mammals, state fossils span hundreds of millions of years of life on Earth: they include dinosaurs (Utah’s Allosaurus, South Dakota’s Triceratops, New Jersey’s Hadrosaurus, Oklahoma’s Saurophaganax), prehistoric whales (Alabama, Mississippi), mammoths and mastodons (Alaska, Michigan, Nebraska, South Carolina, Washington), giant sharks (North Carolina’s Megalodon tooth), marine reptiles (Nevada’s Ichthyosaur), trilobites (Ohio, Pennsylvania, Wisconsin), prehistoric plants (Maine, Oregon, Louisiana), and invertebrates like crinoids and brachiopods. Several states have designated both a state fossil and a separate state dinosaur.
Nebraska was first, designating the mammoth as state fossil in 1967. North Dakota followed within months with teredo-bored petrified wood. Most state fossil designations came in the 1980s and 1990s, with a steady trickle of new designations continuing into the 2010s. Many are the direct result of sustained campaigns by elementary school students working with state geological surveys or local museums: the classic “classroom-to-capitol” civics-plus-science project.
This guide covers every US state fossil in detail, including year adopted, what each specimen is, how old it is, and why each state chose it. For more state animal symbols, see our guides to state reptiles, state mammals, state marine mammals, state fish, state birds, state dog breeds, state insects, state butterflies, state horses and state amphibians.
Key facts about US state fossils
- 41 US states have designated an official state fossil.
- First US state fossil: Nebraska’s mammoth, 1967.
- Most recent: North Carolina’s Megalodon tooth (2013), Kansas’s Tylosaurus and Pteranodon dual designation (2014), and South Carolina’s Columbian Mammoth (2014) are among the most recent.
- Most common fossil type: dinosaurs and other Mesozoic reptiles (around 10 states), followed by mammoths and mastodons (6 states), then trilobites (3-4 states).
- Largest state fossil: Nevada’s Ichthyosaur Shonisaurus popularis, which reached 15 metres long. Oklahoma’s Saurophaganax may have been the largest known land predator, potentially exceeding Tyrannosaurus in length.
- Smallest state fossil: Pennsylvania’s Phacops rana trilobite and Wisconsin’s Calymene trilobite, both roughly 10 cm.
- Oldest state fossil: Maine’s Pertica quadrifaria, a 390-million-year-old Devonian plant.
- Youngest state fossil: Vermont’s Charlotte Whale (beluga), approximately 11,500 years old, a relict from the post-glacial Champlain Sea.
How states pick their fossils
State fossil designations are driven by a distinctive combination of voices: state geological surveys, natural history museums, university palaeontology departments, and schoolchildren. More than any other state symbol category, state fossil designations are often the outcome of multi-year educational campaigns in which schoolchildren research candidate species, write bills, testify before committees, and lobby legislators directly. The “state fossil civics project” is a standard feature of American middle-school science education in some states.
Three main rationales recur in state fossil picks:
- In-state discovery or type locality. Many state fossils were first described from specimens found in the state, making the state the “type locality” for the species. Colorado’s Stegosaurus was first found at the Morrison Formation; Nevada’s Ichthyosaur is named after the Shoshone people; New Jersey’s Hadrosaurus foulkii was the first nearly-complete dinosaur skeleton discovered in North America (1858).
- Abundance in state fossil beds. Some picks reflect species that are famously abundant in state rock formations: the Pennsylvania trilobite, the Wisconsin trilobite, the Missouri crinoid, the Kentucky brachiopod.
- Charismatic megafauna. Dinosaurs and mammoths tend to win when they’re on the ballot. South Dakota (Triceratops), Utah (Allosaurus), Alaska (Woolly Mammoth), Michigan (Mastodon) and Texas (Paluxysaurus) all picked the most instantly recognisable prehistoric species available to them.
State fossils at a glance
| State | State fossil | Type | Year adopted |
|---|---|---|---|
| Alabama | Basilosaurus cetoides | Prehistoric whale | 1984 |
| Alaska | Woolly Mammoth | Mammal | 1986 |
| Arizona | Sonorasaurus thompsoni (state dinosaur) | Dinosaur | 2018 |
| California | Saber-toothed Cat (Smilodon) | Mammal | 1973 |
| Colorado | Stegosaurus | Dinosaur | 1982 |
| Connecticut | Eubrontes giganteus (dinosaur track) | Dinosaur track | 1991 |
| Delaware | Belemnitella americana | Cephalopod | 1996 |
| Georgia | Shark Tooth | Shark fossil | 1976 |
| Idaho | Hagerman Horse (Equus simplicidens) | Mammal | 1988 |
| Illinois | Tully Monster (Tullimonstrum gregarium) | Invertebrate | 1989 |
| Kansas | Tylosaurus (marine) + Pteranodon (flying) | Marine reptile + pterosaur | 2014 |
| Kentucky | Brachiopod | Invertebrate | 1986 |
| Louisiana | Petrified Palmwood | Plant | 1976 |
| Maine | Pertica quadrifaria | Plant | 1985 |
| Maryland | Ecphora gardnerae | Snail shell | 1994 |
| Massachusetts | Dinosaur Tracks | Dinosaur track | 1980 |
| Michigan | Mastodon | Mammal | 2002 |
| Mississippi | Basilosaurus cetoides (Prehistoric whale) | Whale | 1981 |
| Missouri | Crinoid | Invertebrate | 1989 |
| Montana | Maiasaura peeblesorum (duck-billed) | Dinosaur | 1985 |
| Nebraska | Mammoth | Mammal | 1967 |
| Nevada | Ichthyosaur (Shonisaurus popularis) | Marine reptile | 1977 |
| New Jersey | Hadrosaurus foulkii | Dinosaur | 1991 |
| New Mexico | Coelophysis bauri | Dinosaur | 1981 |
| New York | Eurypterus remipes (sea scorpion) | Invertebrate | 1984 |
| North Carolina | Megalodon tooth | Shark fossil | 2013 |
| North Dakota | Teredo-bored Petrified Wood | Plant (with mollusc traces) | 1967 |
| Ohio | Isotelus (trilobite) | Invertebrate | 1985 |
| Oklahoma | Saurophaganax maximus | Dinosaur | 2000 |
| Oregon | Metasequoia (Dawn Redwood) | Plant | 2005 |
| Pennsylvania | Phacops rana (trilobite) | Invertebrate | 1988 |
| South Carolina | Columbian Mammoth | Mammal | 2014 |
| South Dakota | Triceratops | Dinosaur | 1988 |
| Tennessee | Pterotrigonia thoracica | Bivalve | 1998 |
| Texas | Paluxysaurus jonesi | Dinosaur | 2009 |
| Utah | Allosaurus + Utahraptor (state dinosaur) | Dinosaur | 1988 / 2018 |
| Vermont | Charlotte Whale (beluga) + Mt Holly Mammoth | Mammal | 1993 / 2014 |
| Virginia | Chesapecten jeffersonius | Bivalve | 1993 |
| Washington | Columbian Mammoth | Mammal | 1998 |
| West Virginia | Jefferson’s Ground Sloth (Megalonyx) | Mammal | 2008 |
| Wisconsin | Calymene celebra (trilobite) | Invertebrate | 1986 |
| Wyoming | Knightia eocaena + Triceratops (state dinosaur) | Fish + Dinosaur | 1987 / 1994 |
State fossils by type
Dinosaurs (10+ states)
Dinosaurs dominate the state fossil list. States with dinosaur or dinosaur-related state fossils include Colorado (Stegosaurus), Connecticut (Eubrontes tracks), Massachusetts (dinosaur tracks), Montana (Maiasaura), New Jersey (Hadrosaurus foulkii), New Mexico (Coelophysis), Oklahoma (Saurophaganax), South Dakota (Triceratops), Texas (Paluxysaurus jonesi), and Utah (Allosaurus). Arizona, Maryland, Wyoming, and Washington DC have separate state dinosaur designations. For more species-level information, see our dinosaur guides at dinosaur names.
Mammoths and mastodons (6 states)
Six states designated Pleistocene elephant-relatives as state fossils: Alaska (Woolly Mammoth), Michigan (Mastodon), Nebraska (Mammoth, the first US state fossil), South Carolina (Columbian Mammoth), Vermont (Mount Holly Mammoth) and Washington (Columbian Mammoth). Woolly mammoths were smaller but better adapted to cold; Columbian mammoths were larger and lived across the warmer parts of North America; mastodons were older lineages distinct from mammoths entirely. All three went extinct around 10,000-11,000 years ago, shortly after humans arrived in North America.
Marine reptiles (2 states)
Nevada’s Ichthyosaur (Shonisaurus popularis) is one of the most dramatic state fossils, a 15-metre Triassic marine reptile found in astonishing numbers at Berlin-Ichthyosaur State Park. Kansas designated Tylosaurus, a large mosasaur (marine reptile from the Late Cretaceous Western Interior Seaway that once covered Kansas), as state marine fossil in 2014, alongside Pteranodon (a flying reptile from the same seaway) as state flying fossil.
Prehistoric whales (2 states)
Alabama and Mississippi both designated Basilosaurus cetoides, a 20-metre serpentine early whale from the Eocene. Despite the “saurus” in the name (originally mistaken for a sea reptile when first described in 1834), Basilosaurus is an ancient whale with small hind legs, reflecting whales’ evolutionary descent from land mammals. Fossils are abundant in Alabama and Mississippi marine sediments.
Trilobites (3 states)
Three states designated trilobites, the iconic segmented marine arthropods of the Palaeozoic era: Ohio’s Isotelus, Pennsylvania’s Phacops rana and Wisconsin’s Calymene celebra. Trilobites thrived for nearly 300 million years (Cambrian to Permian) before going extinct in the end-Permian mass extinction. All three state trilobites lived in the shallow seas that covered much of North America during the Ordovician, Silurian and Devonian periods.
Prehistoric plants (4 states)
Four states designated prehistoric plant fossils: Louisiana (Petrified Palmwood), Maine (Pertica quadrifaria, one of the earliest known vascular plants), North Dakota (Teredo-bored petrified wood), and Oregon (Metasequoia, the dawn redwood, a “living fossil” gymnosperm rediscovered alive in China in 1944 after being known only as a fossil).
Molluscs and other invertebrates (7+ states)
Delaware (Belemnite), Illinois (Tully Monster), Kentucky (Brachiopod), Maryland (Ecphora snail), Missouri (Crinoid), New York (Eurypterus sea scorpion), Tennessee (Pterotrigonia bivalve), and Virginia (Chesapecten bivalve) all designated marine invertebrate fossils. Illinois’s Tully Monster (Tullimonstrum gregarium) is the most unusual: its taxonomic classification remains disputed after 60+ years of study.
Other (mammals, sharks, fish)
California’s Saber-toothed Cat (Smilodon), Idaho’s Hagerman Horse, West Virginia’s Jefferson’s Ground Sloth, Georgia’s shark tooth, North Carolina’s Megalodon tooth, and Wyoming’s Knightia fish round out the miscellaneous category. Megalodon was the largest shark that ever lived, reaching 18-20 metres; its teeth are commonly found on North Carolina beaches.
The Complete State-by-State Guide
Alabama, Basilosaurus cetoides
Alabama designated Basilosaurus cetoides as state fossil in 1984. Basilosaurus was a long, serpentine early whale that lived in the warm tropical seas covering much of Alabama during the Eocene epoch, around 40 million years ago. Adult Basilosaurus reached 15-20 metres in length with elongated bodies that swam by undulating their tail flukes. Despite their whale identity, they retained small, reduced hind legs, a striking evolutionary remnant of their land-mammal ancestry. Alabama is one of the world’s best sources of Basilosaurus fossils, with exceptional specimens housed at the Alabama Museum of Natural History.
Alaska, Woolly Mammoth
Alaska designated the woolly mammoth (Mammuthus primigenius) as state fossil in 1986. Alaska holds some of the best-preserved woolly mammoth remains on Earth, thanks to the permafrost that has kept some specimens frozen for tens of thousands of years with intact skin, hair, muscle and stomach contents. Woolly mammoths were smaller than their warm-climate cousins (3-3.5 metres at the shoulder), thickly coated in shaggy hair, with small ears and tails to minimise heat loss. Alaska’s Pleistocene tundra hosted woolly mammoth populations until around 10,000 years ago, with the last known isolated population surviving on Wrangel Island, Russia until just 4,000 years ago.
Arizona, Sonorasaurus thompsoni
Arizona designated Sonorasaurus thompsoni as state dinosaur in 2018. Sonorasaurus was a medium-sized brachiosaurid sauropod that lived in what is now southeastern Arizona during the middle Cretaceous, around 112 million years ago. The species was discovered by geology student Richard Thompson in 1994 and named after both the Sonoran Desert and its discoverer. Arizona’s state rock is petrified wood, designated separately; the state fossil designation in the form of a dinosaur was added later to complement the state’s palaeontological legacy.
California, Saber-toothed Cat (Smilodon)
California designated the saber-toothed cat (Smilodon fatalis) as state fossil in 1973. California’s La Brea Tar Pits in Los Angeles contain one of the richest saber-toothed cat fossil deposits in the world, with over 2,000 individual Smilodon specimens recovered. The species had massive, 18-cm curved canine teeth used to deliver precisely targeted killing bites to large prey. Smilodon went extinct around 10,000 years ago, at the end of the last ice age. Despite the popular name “saber-toothed tiger,” Smilodon wasn’t closely related to tigers (or any living big cat).
Colorado, Stegosaurus
Colorado designated Stegosaurus as state fossil in 1982 after a sustained campaign by Colorado elementary schoolchildren. The first Stegosaurus fossils were discovered at Morrison, Colorado, in 1877, making Colorado the type locality for the species. Stegosaurus was a large (up to 9 metres) Late Jurassic herbivorous dinosaur famous for the double row of bony plates along its back and four tail spikes (the “thagomizer”). The brain-to-body ratio of Stegosaurus was unusually low: a 4.5-tonne adult had a brain weighing only around 80 grams, roughly the size of a walnut.
Connecticut, Eubrontes giganteus
Connecticut designated Eubrontes giganteus (a dinosaur track species) as state fossil in 1991. Connecticut’s Jurassic-age sandstones hold thousands of three-toed theropod dinosaur footprints, particularly at Dinosaur State Park in Rocky Hill, where over 500 visible tracks are preserved in situ under a protective dome. The tracks are 200 million years old and were almost certainly left by a large theropod dinosaur similar to Dilophosaurus, though the actual body fossils have never been found in Connecticut. The park’s discovery in 1966 (during highway construction) was one of the most significant palaeontological finds in New England history.
Delaware, Belemnitella americana
Delaware designated Belemnitella americana (a belemnite, or fossil squid-relative) as state fossil in 1996. Belemnites were extinct cephalopods related to modern squid, with an internal rod-shaped skeleton (the “guard”) made of calcite; the guards are what fossilised and are commonly found in Cretaceous marine sediments along the Delaware coast. Belemnites went extinct at the end of the Cretaceous, 66 million years ago, alongside the non-avian dinosaurs.
Georgia, Shark Tooth
Georgia designated the shark tooth (no species specified) as state fossil in 1976. Georgia’s coastal plain, particularly the Savannah River area, is rich in fossilised shark teeth from multiple species and epochs, including Miocene and Pliocene megalodon teeth. Savannah and surrounding beaches are famous destinations for amateur fossil hunters looking for shark teeth washed out by tidal action. Georgia was one of the earliest US states to designate a state fossil.
Idaho, Hagerman Horse
Idaho designated the Hagerman Horse (Equus simplicidens) as state fossil in 1988. The Hagerman Horse was an early true horse that lived in southern Idaho during the late Pliocene, around 3-3.5 million years ago. Hundreds of nearly complete skeletons have been recovered from the Hagerman Fossil Beds along the Snake River, making it one of the world’s richest early-horse fossil sites. Modern horses trace their ancestry through this lineage; the Hagerman Horse is sometimes called the “founding horse” of the modern genus Equus.
Illinois, Tully Monster
Illinois designated the Tully Monster (Tullimonstrum gregarium) as state fossil in 1989. The Tully Monster is one of the strangest animals in the fossil record: a 30-cm soft-bodied invertebrate with a long proboscis ending in jaws, eyes mounted on a transverse bar across the body, and a fin-like tail. Fossils are found only in the Mazon Creek Lagerstätte of Illinois, in concretions from the Middle Pennsylvanian (around 309 million years ago). Despite 60 years of study, Tully Monster’s taxonomic classification remains disputed: proposed identifications have ranged from molluscs to chordates to vertebrates to none of the above.
Kansas, Tylosaurus and Pteranodon
Kansas designated Tylosaurus as state marine fossil and Pteranodon as state flying fossil, both in 2014. During the Late Cretaceous, much of Kansas was covered by the Western Interior Seaway, a shallow sea that teemed with marine reptiles including Tylosaurus proriger, a 14-metre mosasaur at the top of the food chain, and Pteranodon, a large flying reptile with up to a 7-metre wingspan. Both are extraordinarily well-preserved in Kansas’s Smoky Hill Chalk, one of the world’s richest Late Cretaceous marine fossil formations.
Kentucky, Brachiopod
Kentucky designated the brachiopod (no species specified) as state fossil in 1986. Brachiopods are marine invertebrates superficially resembling clams but belonging to an entirely separate phylum; Kentucky’s Ordovician limestone formations, particularly around Cincinnati, are among the most brachiopod-rich rocks in North America, with dozens of species preserved in abundance. Brachiopod fossils are so common in Kentucky road cuts and stream beds that they’re a standard classroom collecting target for Kentucky elementary school science classes.
Louisiana, Petrified Palmwood
Louisiana designated petrified palmwood as state fossil in 1976. Louisiana’s Oligocene-era palm forests (about 30 million years old) were buried, silicified, and preserved as petrified wood that often retains visible cellular structure and vascular patterns. The palmwood is found along the Catahoula Formation and other rock units, particularly in the central and northern parts of the state. Louisiana petrified palmwood is prized by collectors for its rich red, orange and brown colours and distinctive rod-like vascular pattern.
Maine, Pertica quadrifaria
Maine designated Pertica quadrifaria as state fossil in 1985. It’s a Devonian-age plant from approximately 390 million years ago, one of the earliest known vascular plants on Earth. Pertica was a small, leafless plant with a branching stem bearing spore-producing structures, representing an early experiment in terrestrial plant evolution. Maine’s Trout Valley Formation in the Baxter State Park area is the type locality. Maine’s choice makes Pertica the oldest US state fossil by geological age.
Maryland, Ecphora gardnerae
Maryland designated Ecphora gardnerae (a Miocene-age extinct snail) as state fossil in 1994. Maryland also designated Astrodon johnstoni as state dinosaur in 1998. Ecphora was one of the first North American fossils to be scientifically described (1685), placing Maryland at the heart of early American palaeontology history. The Calvert Cliffs along Maryland’s Chesapeake Bay coast are one of the richest Miocene marine fossil localities in the world.
Massachusetts, Dinosaur Tracks
Massachusetts designated dinosaur tracks as state fossil in 1980. Massachusetts’s Connecticut River Valley holds thousands of Early Jurassic dinosaur tracks preserved in sandstone, particularly in the Holyoke and South Hadley area. Edward Hitchcock, a 19th-century Massachusetts geologist, catalogued tens of thousands of these tracks starting in the 1830s, though he initially interpreted them as prehistoric bird tracks rather than dinosaur tracks (the concept of dinosaurs was still new). Hitchcock’s collection, now at Amherst College, is one of the foundational dinosaur track collections in the world.
Michigan, Mastodon
Michigan designated the American Mastodon (Mammut americanum) as state fossil in 2002. Michigan holds one of the highest densities of American mastodon fossil discoveries in the US, with hundreds of individual mastodon remains recovered from the state’s peat bogs, lake sediments and farm fields. Mastodons are distinct from mammoths: they were slightly shorter, more stoutly built, had straighter tusks, and fed primarily on woody browse (tree twigs and leaves) rather than the grasses that mammoths ate. Both went extinct around 10,000 years ago, shortly after human arrival in North America.
Mississippi, Basilosaurus cetoides
Mississippi designated Basilosaurus cetoides as state fossil in 1981. Mississippi and Alabama share the same prehistoric whale as state fossil, as both states lie over the same Eocene marine sediments where Basilosaurus was abundant. Large numbers of nearly complete Basilosaurus skeletons have been excavated from Mississippi farm fields, where plough blades have turned up enormous fossilised vertebrae for over a century. The species was originally mistaken for a giant reptile (hence the “-saurus” ending); its correct identification as an early whale was established in 1840.
Missouri, Crinoid
Missouri designated the crinoid as state fossil in 1989. Crinoids are marine invertebrates related to starfish and sea urchins, with long segmented stalks and feather-like arms used for filter feeding. Missouri’s Mississippian-age limestones (roughly 340 million years old) hold some of the world’s most spectacular crinoid fossils, often in complete slabs showing dozens of individuals preserved together. The Burlington Limestone of northern Missouri is sometimes nicknamed the “crinoidal limestone” for its crinoid abundance.
Montana, Maiasaura peeblesorum
Montana designated Maiasaura peeblesorum (a duck-billed dinosaur) as state fossil in 1985. Maiasaura means “good mother lizard,” named for the fossil nests found in Montana’s Two Medicine Formation that showed extensive parental care: adults returned to nests with food for hatchlings, an unusual behavioural pattern for dinosaurs that transformed scientific understanding of dinosaur behaviour. The Two Medicine fossil beds contain thousands of Maiasaura specimens, including nests with eggs, embryos and juveniles, making Montana’s state fossil one of the best-understood dinosaurs anywhere.
Nebraska, Mammoth
Nebraska designated the mammoth (unspecified species) as state fossil in 1967, the first state fossil designation in the United States. Nebraska holds extraordinary mammoth fossil resources: the Ashfall Fossil Beds in north-central Nebraska preserve hundreds of Miocene mammoths (and other mammals) killed together by volcanic ash from an eruption in what is now Idaho, creating a pompeii-like snapshot of a 12-million-year-old ecosystem. Nebraska’s Pleistocene mammoth fossils are also abundant, with multiple complete skeletons displayed at the University of Nebraska State Museum.
Nevada, Ichthyosaur (Shonisaurus popularis)
Nevada designated Shonisaurus popularis, a Triassic ichthyosaur, as state fossil in 1977. Shonisaurus was one of the largest marine reptiles to ever live, reaching 15 metres in length and weighing up to 40 tonnes. Nevada’s Berlin-Ichthyosaur State Park, in Nye County, contains the largest known concentration of Shonisaurus fossils: over 40 individuals died together, possibly during a mass stranding or red-tide event 225 million years ago. The park preserves fossils in situ in an excavation quarry, still partially embedded in the rock where they died.
New Jersey, Hadrosaurus foulkii
New Jersey designated Hadrosaurus foulkii as state dinosaur and state fossil in 1991. Hadrosaurus is historically the most important duck-billed dinosaur ever discovered: the 1858 find in a Haddonfield, New Jersey marl pit was the first nearly-complete dinosaur skeleton ever assembled anywhere in the world, and its display at the Academy of Natural Sciences in Philadelphia launched a new era of dinosaur palaeontology. The skeleton demonstrated for the first time that some dinosaurs walked on two legs, contradicting earlier crocodilian-style reconstructions. Hadrosaurus lived around 80 million years ago in the Late Cretaceous.
New Mexico, Coelophysis bauri
New Mexico designated Coelophysis bauri as state fossil in 1981. Coelophysis was a small (3-metre), slender theropod dinosaur that lived around 200-215 million years ago in the Late Triassic. New Mexico’s Ghost Ranch, near Abiquiu, yielded hundreds of Coelophysis skeletons preserved together in 1947, in what’s interpreted as a catastrophic flood deposit. The species is one of the earliest known dinosaurs and among the most completely understood. Edwin Colbert’s 1947 excavation at Ghost Ranch is a landmark in North American palaeontology.
New York, Eurypterus remipes
New York designated Eurypterus remipes (a sea scorpion, technically a eurypterid) as state fossil in 1984. Eurypterids were marine arthropods that lived in shallow seas during the Silurian and Devonian, reaching up to 2 metres in length. Eurypterus specimens from New York’s Bertie Formation are among the most beautifully preserved eurypterids in the world, sometimes with exquisite detail of appendages and eyes. New York’s eurypterids were typically 10-20 cm long, not the giant species. They’re often considered the closest living relatives of horseshoe crabs, which are themselves closer to spiders than to true crabs.
North Carolina, Megalodon Tooth
North Carolina designated the fossilised tooth of Carcharocles megalodon (the megalodon shark) as state fossil in 2013. Megalodon was the largest shark that ever lived, reaching 18 metres in body length with teeth up to 18 cm in slant height. The species went extinct around 3.6 million years ago. Megalodon teeth are regularly found on North Carolina beaches, particularly along the Cape Fear River and around Aurora (where the PCS phosphate mine periodically dumps fossil-bearing spoil for amateur fossil hunters). North Carolina’s “fossil capital” at Aurora celebrates its megalodon heritage with an annual fossil festival.
North Dakota, Teredo-bored Petrified Wood
North Dakota designated teredo-bored petrified wood as state fossil in 1967, making it jointly the first state fossil (with Nebraska, both adopted in 1967). The fossil is specifically petrified wood riddled with small holes made by Teredo shipworm molluscs. The wood is Paleocene-age (around 55-60 million years old) and was originally driftwood floating in a shallow sea that covered much of North Dakota; the shipworms bored into the wood while it was still wet, then the whole thing was buried, silicified and preserved. The combination of plant and animal trace fossil makes it unusually informative about the ancient ecosystem.
Ohio, Isotelus Trilobite
Ohio designated Isotelus as state fossil in 1985. Isotelus was a large trilobite, with Ohio specimens reaching 70 cm in length (enormous by trilobite standards). Ohio’s Ordovician-age Cincinnati Arch region holds some of the world’s most abundant and best-preserved Isotelus fossils, particularly in road cuts and natural exposures around Cincinnati. The species lived in the shallow tropical sea that covered Ohio around 450 million years ago.
Oklahoma, Saurophaganax maximus
Oklahoma designated Saurophaganax maximus as state fossil in 2000. Saurophaganax means “lord of lizard-eaters,” a fitting name for what may have been the largest predator of the Late Jurassic: estimated at 10-13 metres in length and possibly larger than Tyrannosaurus rex. The species is known from partial skeletons in Oklahoma’s Panhandle, in the Morrison Formation. Some palaeontologists consider Saurophaganax to be a very large species of Allosaurus rather than a separate genus, a debate that continues.
Oregon, Metasequoia (Dawn Redwood)
Oregon designated Metasequoia (the dawn redwood) as state fossil in 2005. Dawn redwoods were widespread across North America during the Miocene (5-25 million years ago) and were especially common in Oregon’s wet forests. The species was thought extinct until 1944, when living Metasequoia trees were discovered in a remote Chinese valley, making it a true “living fossil.” Oregon’s Clarno, John Day and Mascall fossil beds are world-famous for dawn redwood and other plant fossils of the same age.
Pennsylvania, Phacops rana Trilobite
Pennsylvania designated Phacops rana as state fossil in 1988. Phacops was a Devonian trilobite (around 390 million years old) famous for its prominent compound eyes, among the earliest and most sophisticated eyes in the fossil record. Each eye contained 30-100 individual calcite lenses arranged in a tight mosaic, allowing the trilobite to see its surroundings in all directions simultaneously. Pennsylvania’s Devonian-age Hamilton and Marcellus formations are major Phacops fossil localities.
South Carolina, Columbian Mammoth
South Carolina designated the Columbian Mammoth (Mammuthus columbi) as state fossil in 2014. Columbian Mammoths were larger than woolly mammoths, standing up to 4 metres at the shoulder and weighing up to 10 tonnes; they ranged across the warm-climate parts of North America. South Carolina’s Columbian Mammoth fossils come primarily from Pleistocene river deposits along the Savannah, Edisto and Cooper rivers, with teeth and tusks regularly exposed by tidal erosion. South Carolina was one of the earliest regions in the US where mammoth teeth were scientifically recognised, with finds described as early as 1725.
South Dakota, Triceratops
South Dakota designated Triceratops as state fossil in 1988. Triceratops horridus was one of the last non-avian dinosaurs to evolve, appearing around 68 million years ago and going extinct 66 million years ago at the end-Cretaceous mass extinction. South Dakota’s Hell Creek Formation has yielded numerous Triceratops specimens, including some of the most famous individuals in palaeontology. Adult Triceratops reached 9 metres in length with skulls up to 2.5 metres long, carrying two brow horns and one nose horn alongside a broad bony frill.
Tennessee, Pterotrigonia thoracica
Tennessee designated Pterotrigonia thoracica, a Late Cretaceous bivalve mollusc, as state fossil in 1998. Pterotrigonia was a clam-like mollusc that lived in the shallow Mississippi Embayment sea that covered western Tennessee around 70 million years ago. The shells are common in Tennessee’s Late Cretaceous sediments and often preserve their original iridescent mother-of-pearl inner layer (nacre), making them prized by amateur collectors. The species went extinct at the end of the Cretaceous along with the non-avian dinosaurs.
Texas, Paluxysaurus jonesi
Texas designated Paluxysaurus jonesi as state dinosaur in 2009, later reclassified as a species of Sauroposeidon. The species lived around 112 million years ago in the Early Cretaceous and is known from partial skeletons at the Jones Ranch quarry in Hood County, Texas. Paluxy River dinosaur tracks, made partly by the same species, are among the most famous dinosaur trackways in the world, preserving sauropod and theropod tracks in the river bed that are sometimes exposed during low water. The Paluxy tracks were also the source of much-debated (and debunked) “man-and-dinosaur” track claims in the mid-20th century.
Utah, Allosaurus and Utahraptor
Utah designated Allosaurus as state fossil in 1988 and added Utahraptor ostrommaysi as state dinosaur in 2018. Allosaurus was a large (8-12 metre) theropod that lived around 150 million years ago in the Late Jurassic and is extraordinarily well-represented in Utah’s Cleveland-Lloyd Dinosaur Quarry, where 46 individuals have been excavated, making it one of the densest dinosaur fossil deposits in the world. Utahraptor, at 7 metres long, was the largest known dromaeosaurid (raptor) dinosaur and lived in Utah around 125 million years ago.
Vermont, Charlotte Whale and Mt Holly Mammoth
Vermont has two state fossil designations. The Charlotte Whale (a beluga whale) was designated state marine fossil in 1993; the specimen, discovered in 1849 during railroad construction in Charlotte, Vermont, is an 11,500-year-old skeleton that washed up during the post-glacial Champlain Sea period when central Vermont was submerged by a marine inlet. The Mount Holly Mammoth was designated state terrestrial fossil in 2014, based on tusk and tooth fragments found in southern Vermont. The Charlotte Whale is one of the youngest state fossils in the US.
Virginia, Chesapecten jeffersonius
Virginia designated Chesapecten jeffersonius, an extinct scallop, as state fossil in 1993. The species is named after Thomas Jefferson, who collected and studied fossil shells at his Monticello estate and published scientific observations on Virginia fossils in 1787. Virginia’s Yorktown Formation (Pliocene, around 3-5 million years old) is the type locality for the species, with shell beds exposed along the York River. Chesapecten shells are abundant enough in Virginia that they’re a standard school collecting target.
Washington, Columbian Mammoth
Washington designated the Columbian Mammoth as state fossil in 1998. Washington was at the northern edge of the Columbian Mammoth range (where they overlapped with woolly mammoths) and mammoth fossils have been recovered from several Pleistocene deposits across the state, particularly in the Cascade foothills. The species went extinct around 10,000 years ago. Washington and South Carolina both share the Columbian Mammoth as state fossil.
West Virginia, Jefferson’s Ground Sloth
West Virginia designated Jefferson’s Ground Sloth (Megalonyx jeffersonii) as state fossil in 2008. The species is named after Thomas Jefferson, who described the first specimen (bones recovered from a West Virginia cave) in 1797, mistakenly assuming they were from a giant predator he called “Megalonyx” (meaning “giant claw”). Jefferson sent his paper to the American Philosophical Society and is sometimes credited as the founder of American vertebrate palaeontology. Megalonyx was a bear-sized ground sloth that went extinct around 10,000 years ago.
Wisconsin, Calymene celebra
Wisconsin designated Calymene celebra as state fossil in 1986. Calymene was a Silurian-age trilobite that lived in the shallow tropical sea that covered Wisconsin around 425 million years ago. The species is commonly found in Wisconsin’s Racine Dolomite formation, where it’s often preserved enrolled (curled up into a defensive ball like a modern pill bug). Enrolling was a widespread trilobite defensive behaviour, and Calymene specimens preserved in this position are particularly prized by collectors.
Wyoming, Knightia eocaena and Triceratops
Wyoming designated Knightia eocaena, a small herring-like fish, as state fossil in 1987, and Triceratops as state dinosaur in 1994. Wyoming’s Green River Formation (Eocene, around 50 million years old) is one of the world’s premier lagerstätte deposits, with literally billions of Knightia fossils preserved in finely-laminated shale beds. Wyoming’s Triceratops designation recognises the state’s abundant Late Cretaceous horned dinosaur fossils, particularly from the Lance Formation.
US states without a state fossil
Nine US states have no official state fossil: Arkansas, Hawaii, Indiana, Iowa, Minnesota, New Hampshire, Rhode Island, and a few others. Hawaii’s lack of a state fossil reflects the islands’ geologically young volcanic origin (the oldest Hawaiian islands are only around 5 million years old, and the main islands much younger); there simply aren’t significant fossil deposits. Indiana’s lack is surprising given its extensive limestone fossil resources. Minnesota, Rhode Island and New Hampshire have seen various fossil candidates proposed but none successfully designated.
Washington DC has designated a “state dinosaur” despite not being a state: Capitalsaurus, named for the fragmentary specimen found near the US Capitol in 1898. It’s the only dinosaur genus named after a US government building.
Notable firsts and quirky facts about US state fossils
- First US state fossil: Nebraska’s mammoth and North Dakota’s petrified wood, both 1967.
- Most recent: Arizona’s Sonorasaurus (state dinosaur, 2018), Utah’s Utahraptor (state dinosaur, 2018), and Kansas’s Tylosaurus/Pteranodon (2014).
- Only state fossil with fossils still embedded in the rock at a state park: Nevada’s Ichthyosaurs (Berlin-Ichthyosaur State Park), Connecticut’s dinosaur tracks (Dinosaur State Park), and Wyoming’s Fossil Butte.
- Only state fossil described by a US president: West Virginia’s Jefferson’s Ground Sloth, described by Thomas Jefferson in 1797.
- Only state fossil named after a president: Jefferson’s Ground Sloth (Megalonyx jeffersonii, West Virginia), also Virginia’s Chesapecten jeffersonius named after Jefferson.
- Only state fossil named after a US government building: Washington DC’s Capitalsaurus.
- Only state fossil that was a living species rediscovered after being known only as a fossil: Oregon’s Metasequoia (dawn redwood), rediscovered alive in China in 1944.
- Oldest state fossil by geological age: Maine’s Pertica quadrifaria (390 million years old, Devonian).
- Youngest state fossil: Vermont’s Charlotte Whale (11,500 years old, post-Pleistocene).
- Only state fossil with disputed taxonomic classification after 60+ years of study: Illinois’s Tully Monster.
- Only state fossil that is technically a trace (track) rather than a body fossil: Connecticut’s Eubrontes and Massachusetts’s dinosaur tracks.
- Two states with state dinosaurs separate from state fossils: Utah (Allosaurus state fossil + Utahraptor state dinosaur), Wyoming (Knightia state fossil + Triceratops state dinosaur).
Frequently asked questions about US state fossils
How many US states have a state fossil?
Approximately 41 US states have designated an official state fossil. Several states (Utah, Wyoming, Vermont, Maryland, Kansas) have multiple fossil-related designations, including separate state dinosaur, state marine fossil, or state terrestrial fossil categories.
Which state was the first to pick a state fossil?
Nebraska and North Dakota both designated state fossils in 1967, with Nebraska’s mammoth and North Dakota’s teredo-bored petrified wood. Nebraska’s designation is often cited as the first US state fossil.
What US states have dinosaurs as state fossils?
At least 10 states have a dinosaur (or dinosaur track) as state fossil: Colorado (Stegosaurus), Connecticut (Eubrontes tracks), Massachusetts (dinosaur tracks), Montana (Maiasaura), New Jersey (Hadrosaurus foulkii), New Mexico (Coelophysis), Oklahoma (Saurophaganax), South Dakota (Triceratops), Texas (Paluxysaurus/Sauroposeidon), and Utah (Allosaurus). Arizona, Utah, Wyoming and Maryland also have separate state dinosaur designations.
What is the oldest US state fossil?
Maine’s Pertica quadrifaria, a Devonian-age plant around 390 million years old, is the oldest US state fossil by geological age. It’s one of the earliest known vascular plants on Earth.
What is the youngest US state fossil?
Vermont’s Charlotte Whale (a beluga whale skeleton approximately 11,500 years old) is the youngest US state fossil. Many mammoth and mastodon state fossils are similarly young (around 10,000-30,000 years old), as they went extinct relatively recently in geological terms.
Do any states have more than one state fossil?
Yes. Utah has both Allosaurus as state fossil and Utahraptor as state dinosaur. Wyoming has Knightia as state fossil and Triceratops as state dinosaur. Vermont has the Charlotte Whale as state marine fossil and the Mount Holly Mammoth as state terrestrial fossil. Kansas has Tylosaurus as state marine fossil and Pteranodon as state flying fossil. Maryland has Ecphora as state fossil and Astrodon as state dinosaur.
Which US state has the most dinosaur-related symbols?
Utah has arguably the most extensive dinosaur-related state symbols, with Allosaurus as state fossil (1988) and Utahraptor as state dinosaur (2018). Wyoming has Knightia (state fossil) and Triceratops (state dinosaur). Both states have extraordinarily rich dinosaur fossil resources.
Is the Megalodon a US state fossil?
Yes. North Carolina designated the fossilised tooth of Carcharocles megalodon as state fossil in 2013. Megalodon teeth are abundant on North Carolina beaches, particularly around the Aurora phosphate mine. Megalodon was the largest shark that ever lived, reaching up to 18 metres, and went extinct around 3.6 million years ago.
What US states don’t have a state fossil?
Around nine US states have no state fossil: Arkansas, Hawaii, Indiana, Iowa, Minnesota, New Hampshire, Rhode Island, and a few others. Hawaii’s lack reflects the state’s young volcanic origin (no ancient fossil deposits). Most others have fielded state fossil bills that never passed.
Can Washington DC have a state fossil?
Washington DC is not a state, but it has designated Capitalsaurus as its official dinosaur (1998). Capitalsaurus is named for a fragmentary fossil found near the US Capitol in 1898. The designation makes DC unique: the only US jurisdiction with a dinosaur named after a US government building.
Explore more US state symbols: state reptiles, state amphibians, state mammals, state marine mammals, state fish, state birds, state dog breeds, state insects, state butterflies, state horses. Or dive into our dinosaur names guide, dinosaur size comparison, and what are fossils? explainer.