Cool creatures from the past and where to see them
Dozens of national park sites bring you face to skull with fossilized critters, showcase the remains of ancient plants, and let you walk among relics from prehistoric eras when the earth and its inhabitants were dramatically different than they are today. Here are a few remarkable specimens from the distant past and the places where you can see them.
1. The Allosaurus
Dinosaur National Monument, Colorado and Utah
This scenic site at the confluence of the Green and Yampa Rivers is the real Jurassic park. If you love dinosaurs, you will love this monument’s exceptional quarry, which features a dense concentration of bones from a variety of prehistoric species. Visitors can see more than 1,500 fossils at the site’s Quarry Exhibit Hall, most of them still partially embedded in the rock. You can even touch dinosaur remains from 149 million years ago. The most common species are sauropods — dinosaurs with long necks — including the Diplodocus, one of the longest known dinosaurs in size. The site also contains remains from more commonly known species such as the Stegosaurus and the Apatosaurus (which is also referred to by the scientifically incorrect name Brontosaurus). It is difficult to pick out just one superstar among these remains; however, the site not only features an excellent reconstruction of the Allosaurus, it also showcases a rare and exceptionally well-preserved skull from this fearsome 30-foot predator that paleontologists believe may have literally eaten other dinosaurs for lunch.
2. The “thunder beast”
John Day Fossil Beds National Monument, Oregon
It may be difficult to picture herds of rhinoceros tromping through east-central Oregon, but relatives of this horned mammal known as brontotheres, or “thunder beasts,” roamed the area 35 million to 50 million years ago. Visually similar to the rhinoceros, these enormous animals are actually more closely related to horses and believed to be social animals; the odd dual horns protruding from the animal’s snout may have been used to compete for mates. The fossils at this picturesque site span 40 million years and offer one of the richest evolutionary records of the Cenozoic Era, including prehistoric alligators, bears, dogs, pigs, horses, cougars and even hippopotamuses. Visit the Thomas Condon Paleontology Center in the Sheep Rock Unit to see more than 500 of these fossils on display, including the “thunder beast.”
3. The Columbian mammoth
Waco Mammoth National Monument, Texas
This relatively new national monument is a significant source for Ice Age fossils, with the oldest specimens dating back 65,000 to 72,000 years. What makes this site unique are its namesake Columbian mammoths. It is the only place in the world where scientists have found a “nursery herd” of these enormous mammals — the remains of a family of females with their babies. Studying the structure of this herd has given paleontologists new insights into how the animals behaved, which, it turns out, may have been remarkably similar to the habits of modern-day elephants. The small portion of the park’s land that researchers have begun excavating has also yielded fossils from a range of other animals, including an American camel, a giant tortoise and a dwarf antelope, as well as a single tooth from a young saber-toothed cat.
4. The Hagerman horse
Hagerman Fossil Beds National Monument, Idaho
This site is the richest known source of Pliocene Epoch fossils in the world, with specimens from more than 200 different species between 3 million and 4 million years old. Numerous creatures lived in this region during that time, including mastodons, bears, saber-toothed cats, Camelops and the earliest known ancestor of the river otter (Lontra weiri, named after musician Bob Weir of the Grateful Dead). Perhaps most notable, however, is the site’s namesake horse. More Hagerman horse fossils have been found here than at any other single site, including more than 30 complete skeletons. The Hagerman horse is the oldest species ever discovered in the Equus family, which includes modern horses, although this prehistoric ancestor more closely resembles zebras (skeletally speaking; whether it had stripes like a zebra remains a mystery). Although most of the fossils at this site are not available for general viewing, the visitor center has Hagerman horse fossils on display, as well as other significant remains from the site.
5. The winged lizard
Big Bend National Park, Texas
Pterosaur literally means “winged lizard,” and these reptiles that lived about 220 million to 65 million years ago were the first vertebrates to develop powered flight (versus gliding). Some pterosaurs were small, with 18-inch wingspans, but the specimen discovered at Big Bend by a research student in 1971 is a whopping 18 feet long — 10 feet taller than Big Bird — with a 36-foot to 39-foot wingspan, roughly the size of a small plane. This animal, known as Quetzalcoatlus northropi, is one of the largest flying creatures ever known to have existed. Scientists believe it was covered in small hair-like fibers, which insulated its body and gave it a furry appearance. Visitors can see a replica of this massive pterosaur at the park’s Panther Junction Visitor Center (the original bones are currently at the University of Texas at Austin).
6. The world’s most concentrated fossil forest
Yellowstone National Park, Idaho, Montana and Wyoming
National Park Service video.
Petrified Forest National Park in Arizona may be famous for its jewel-toned petrified trees, but it is not the only national park with impressive ancient plant life. Yellowstone is not as widely known for its fossilized forest as it is for its geysers and hot springs, but the region’s exceptional geothermal activity was actually responsible for creating its enormous expanse of petrified trees and other flora. Some 50 million years ago, volcanic eruptions covered the area in ash and debris, preserving more than 100 plant species over 40 square miles, preventing the plants from rotting and allowing them to harden, over time, into stone. What’s particularly notable about these mineralized trees is that they still stand upright, as they have for eons, at what is now Specimen Ridge in the northern section of the park.
7. The stromatolite and the trilobite
Grand Canyon National Park, Arizona
The dramatic landscape at this world-famous canyon contains more than one billion years of fossil history, including some of the earliest known life-forms on the planet. The oldest fossils at the Grand Canyon are 1.2-billion-year-old solidified mats of algae from the Precambrian Era known as stromatolites. (Glacier National Park has stromatolites that are even older, from nearly 1.5 billion years ago.) These ancient rocks formed from single-celled organisms known as cyanobacteria; modern stromatolites still exist in a few locations around the globe, including Yellowstone. Perhaps more interesting from an evolutionary perspective are the aquatic lifeforms known as trilobites, which began developing in the Grand Canyon’s waters (among many other places) hundreds of millions of years later in the Paleozoic Era. These creatures are the extinct predecessors of insects, arachnids and crustaceans from a world before beetles, ants, lobsters and spiders existed. Trilobites are the most diverse type of extinct life-form ever discovered; researchers continue to find new species, documenting more than 20,000 of these simple, leggy critters to date.
8. The 20-clawed bat
Fossil Butte National Monument, Wyoming
Some 52 million years ago, a subtropical lake thriving with aquatic animals encompassed the heart of this region; today, park staff poetically refer to Fossil Butte as “America’s aquarium in stone.” Consequently, most of the fossils found here are fish. One notable discovery among Fossil Butte’s few mammals, however, is Onychonycteris finneyi, the world’s earliest known bat. Relatively few bat fossils exist, since their small skeletons decompose easily. But this bat’s remains not only survived — they helped to answer a longstanding scientific question on which evolved first, bats’ flight or echolocation. Because the bat’s small ear bones suggest that it flew without being able to determine its location through reflected sound, scientists now believe that bats developed this skill later in their evolution. This well-preserved fossil also features claws on all five of its digits, not just one or two per hand and foot as later species do, giving the bat its extra-sharp nickname.
9. Prehistoric insects
Florissant Fossil Beds National Monument, Colorado
The most delicate creatures are the quickest to decompose and, as a result, can be the most difficult to find as remains. Yet this site about two hours south of Denver is one of the most diverse insect fossil sites in the world with an impressive trove of specimens from the late Eocene Epoch roughly 35 million years ago. It is amazing to think that hundreds of these fragile creatures survived for millennia sandwiched between thin layers of shale, including beetles, caddisflies, dragonflies, lacewings and mayflies. Among these many arthropods was the first fossilized butterfly ever discovered in North America. (The exceptionally well-preserved specimen, Prodryas persephone, is now in a museum at Harvard University.) The site is also known for its many petrified tree trunks, including the only known trio of interconnected petrified redwood trees in the world.
Tule Springs Fossil Beds National Monument, Nevada
Researchers have spent decades uncovering fossils at this site just half an hour north of Las Vegas, and the Ice Age flora and fauna that lived in this region’s vast desert wetlands date back as far as 100,000 years. The marshes, meadows, streams and pools that once covered this now-arid landscape offered habitat to a diverse assemblage of creatures, including Columbian mammoths, bison and horses (some of the most common residents), as well as saber-toothed cats, dire wolves, American lions and sloths that were as big as cars (some of the rare and fragmented fossils discovered here). Because the deposits are so well dated and the fossils so extensive, scientists are able to study how different animal populations may have waxed and waned in response to climate. One of the more common animals of Tule Springs was Camelops, the last prehistoric camel species native to North America. Researchers are unclear whether the animal — which was closely related to the llama — had a hump like modern camels do. Note that this park site is relatively new and does not yet have visitor services. Anyone may walk among the deposits, but to the untrained eye, the fossils are not apparent. Visit the nearby Nevada State Museum in Las Vegas for more information on Tule Springs and to see remains from the site, including Camelops and mammoth fossils. Fun fact: Tule Springs was also the first site in the United States where scientists used radiocarbon dating to determine fossil age.
11. An ancient fossilized reef
Guadalupe Mountains National Park, Texas
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The American Southwest is known for its arid climate, yet this park site showcases remnants from an underwater world that existed 265 million years ago when this part of West Texas was covered by a tropical inland sea 400 miles long. Today, this area, known as the Permian Reef, is one of the best-preserved fossil reefs on Earth, with numerous tiny marine creatures embedded in the park’s rock. The predominant organisms in this reef were sponges, although algae, corals, oysters, sea urchins, snails and trilobites all lived in this sea over the course of millions of years. Scientists have studied historic sea level rises and drops here to understand how these climate-driven changes affected the ecosystem of fossils preserved at the site. Visitors can see examples of these fossils throughout the park; the 8.4-mile Permian Reef Trail in McKittrick Canyon offers interpretive signs highlighting various aspects of this ancient sea and its diverse lifeforms.
Although some of the best-known paleontological sites are in the Northern Rockies and the Southwest, more than 260 national park sites preserve fossils from a wide variety of flora and fauna. Learn more about the ancient history near you on the National Park Service website.
About the author
Jennifer Errick Managing Editor of Online Communications
Jennifer co-produces NPCA's podcast, The Secret Lives of Parks, and writes, edits and moderates online content.
- Big Bend National Park
- Dinosaur National Monument
- Florissant Fossil Beds National Monument
- Fossil Butte National Monument
- Grand Canyon National Park
- Guadalupe Mountains National Park
- Hagerman Fossil Beds National Monument
- John Day Fossil Beds National Monument
- Tule Springs Fossil Beds National Monument
- Waco Mammoth National Monument
- Yellowstone National Park