Top Ten Parks for Fossils and Dinosaurs - Page 2
Hagerman Fossil Beds National Monument: One of the World's Richest Deposits of Late Pliocene Epoch Fossils
Across the Snake River from Hagerman, Idaho, this monument is significant as one of the world's richest deposits of fossils from the late Pliocene epoch, some three to four million years ago. Chief among them is the Hagerman horse (Equus simplicidens), a small and strongly built horse with a thick neck and muscular forequarters like an African zebra. The earliest specimens date from 3.5 million years ago. The horse became extinct some 10,000 years ago at the end of the last ice age, along with many other large species. Thirty complete skeletons and many partial ones have been excavated since a local rancher discovered the bones in 1928. Besides horses, more than 220 other species (105 vertebrates) have been located in these strata, which represent a variety of ancient habitats, including grassy plains and wetlands. There were mastodons, saber-toothed cats, ground sloths, giant marmots, camels, bears, otters, muskrats, and peccaries. Of two dog species, one was the ancestor of modern coyotes. The other, Borophagus, has no living descendants. It sported a powerful, shortened jaw like that of a hyena, which explains its unofficial name, bone-crushing dog. A visitor center in Hagerman offers displays; ranger-led tours visit the fossil beds in the bluffs across the river.
Guadalupe Mountains National Park: A Fossilized Marine Reef
Far back in the shadows of the Permian era, 265 million years ago, western Texas was near the Equator. Much of it was covered by the Permian Basin, an inland sea. Around its margins there formed a reef— roughly circular, 400 miles long, built up by tiny lime-secreting organisms. Today, this part of Texas is a desert and the reef is an imposing limestone mountain range that ranks as one of the world's best examples of a fossilized marine reef. Its fine-grained stone contains fossils of sea urchins, crinoids, trilobites, nautiloids, and much more. They are important, in part, because they lived before the Great Dying, a catastrophic series of events that drove some 96 percent of marine species into extinction. Hikers can get a geologic tour of the results via the Permian Reef Trail (8.4 miles round-trip).
John Day Fossil Beds National Monument: More Than 700 Known Fossil Sites Spanning 40 Million Years
Scattered among the park's three units are more than 700 known fossil sites spanning 40 million years. Fossils reveal the development of fl owering plants and mammals. They include 14 genera of ancient horse; also prehistoric turtles, alligators, tapirs, rhinos, peccaries, cougars, bears, hippos, and more. Among plants are primitive horsetails, ferns, and ginkgoes, but also flowering species like dogwood, magnolia, beech, and laurel. Visit the paleontology museum at the Sheep Rock Unit. Then hike among the colorful hills on interpretive trails that offer displays and numerous in situ fossils.
Glacier National Park: Stromatolites: Precambrian Fossils
The most scenic fossil sites in America, and among the oldest, lie along the Continental Divide in Montana's Glacier National Park. The fossils themselves aren't much to look at. They are stromatolites, ancient bacterial mats that appear as cabbage-size swirls in the Precambrian rock. If it's Precambrian, it's very old. Stromatolites found in Australia have been dated from 2.7 billion years ago. Other discoveries push the age back to nearly 3.5 billion years ago (keeping in mind that not all stromatolites are caused by living organisms, and they can be difficult to tell apart). In Glacier, stromatolites occur in several rock strata. The Altyn limestone, exposed in areas on the east side of the park, is nearly 1.5 billion years old. The Siyeh, also limestone, dates from 1.1 billion years ago. That's billion with a b, back to the time when life on Earth was dominated by simple forms like blobs of bacteria. In some exposures, the Glacier fossils are packed so densely that the rock seems solid fossil, so much so that one could easily overlook the fossils—and many people do, in part because it's hard to ignore Glacier's extravagant alpine scenery for a bunch of stone cabbages. But just remember this: Tyrannosaurus rex skulls might be more compelling, but stromatolites are older by a thousand million years.
Theodore Roosevelt National Park: Paleocene Epoch Swamp Creatures: Turtles, Crocodilians, Snails, and Clams
In the Paleocene epoch, about 55 million years ago, this part of the Dakota plains was a swamp with a climate resembling that of modern-day southern Louisiana. Dinosaurs had disappeared. Slow-moving rivers coming from the west created a lush delta shaded by sequoia, palm, and magnolia trees. Bald cypresses stood in warm shallows. Turtles and crocodilians swam around their knobby roots. Snails and freshwater clams were abundant. So are their fossils, thanks to the volcanic ash and other sediments exposed in the park's badland canyons. Loop roads in both units of the North Dakota's Theodore Roosevelt park give access to erosional beauties along the Little Missouri River. For walkers, petrified wood can be seen (but never collected) on the Petrifed Forest Loop Trail in the South Unit of the park. The Medora South Unit visitor center sports the skeleton of a crocodile-like Champsosaurus.