Paleontology in Oregon

Oregon's oldest known rock formations are found in the Blue Mountains and the Klamath Mountains. The state's oldest individual rock is a limestone near Suplee dated to nearly 400 million years ago, during the Devonian period of the Paleozoic era. These deposits include conodonts as well as extinct corals and brachiopods, indicating a shallow marine environment. Formations of similar age also include shallow water invertebrates indicating that Oregon's volcanic islands were surrounded by coral reefs, which is consistent with Charles Darwin's theory of reef formation. Fragmentary remains of Permian trilobites, including the endemic species Cummingella oregonensis, have been found in the state's Coyote Butte Formation. == Mesozoic Era ==

Oregon remained covered by shallow seaways throughout the Mesozoic era. Rising temperatures throughout the era led to rising sea levels. Oregon's fossil flora and fauna track these environmental changes with the addition of species adapted to deeper water or more tropical terrestrial conditions. '' A new series of tropical islands emerged during the Triassic period, formed by the merging of the state's older volcanic chains. As in the Paleozoic, shallow water invertebrates made up Oregon's Triassic fauna. These include sponges, ammonites, radiolarians, brachiopods, and the belemnite Aulacoceras. The trace fossil Chondrites, a species of fodinichnid, has been found in the same formations. Although corals have also been found in these assemblages, paleontologists debate the presence of true coral reefs in the region during the Triassic. The oldest vertebrate fossils in Oregon's fossil record appear in Triassic-aged limestones in the Wallowa Mountains. These fossils, including vertebrae, ribs, and a partial skull, have been assigned to the early ichthyosaur genus Shastasaurus. Additionally, a new genus of basal thalattosaur has been recovered from the Brisbois Member of the Vester Formation in Central Oregon near the community of Suplee.''The breakup of the Pangaean supercontinent during the transition to the Jurassic period created a subduction zone in Oregon's ancient seaway, burying older rock formations and giving way to new volcanic island chains.'' These crocodiles likely shared Oregon's Jurassic seaways with ichthyosaurs. Although the mountain range ran along that Cretaceous coast, it was different from Oregon's modern Coast Range. Oregon's vertebrates become more diverse in its Cretaceous fossil record. An amateur discovery in 2005, popularly dubbed "Mitchell's Monster," shows that short-necked plesiosaurs roamed the state's Cretaceous seas along with ichthyosaurs. Other sites nearby in Wheeler County have yielded the remains of Oregon's only known pterosaur, attributed to Bennettazhia oregonensis, as well as teeth from the extinct goblin shark Scapanorhynchus. Only two non-avian dinosaur fossils have been found in Oregon, and both are isolated bones in marine rocks, which evidently bloated and floated out to sea. One is the pedal phalanx of a large (5 m long) ornithopod, intermediate in size and morphology between Tenontosaurus and Eolambia, from the Early Cretaceous (Albian) Hudspeth Shale near Mitchell, Oregon. The other is a sacrum fragment, attributable to a hadrosaur similar to Lambeosaurus, recovered from Late Cretaceous (Campanian) sandstones at Cape Sebastian on the southern Oregon coast. There is no geological record in Oregon of the K-Pg boundary or of the event that ended the Mesozoic era. == Cenozoic Era ==

Oregon's paleoenvironment in the Cenozoic reflected the era's overall global cooling trend, shifting from tropical to temperate to glacial climates. Westward shift in the state's shoreline brought a more diverse terrestrial fauna, including a variety of extinct land mammals. The state's earliest Paleogene deposits record an environment that was warm and wet, similar to the modern American southeast. Invertebrate foramenifera from the Paleogene have been reported from sediments in Coos County, but their identity remains disputed. Other marine invertebrates include echinoderms, foramenifera, brachiopods, scaphopods, shrimp, and crabs. Bony fish included mahi mahi, conger eels, rattails, ancestral billfish, cod, hake, and rockfish. The state's only known fossil egg was found in associated rock formations. The earliest fossils in John Day indicate a subtropical terrestrial environment. The assemblage is rich in fossil seeds, fruit nuts, and associated woods, and is one of the few places in the world where all three are preserved in a single location. The flora included cinnamon, cycads, palms, the primitive sycamore Platanophyllum angustilobus, walnuts, magnolias, figs, grapes, coffee trees, cashews, and bananas. These mammals shared the ecosystem with crocodiles in the genus Pristichampsus and the tortoise Hadrianus. Metasequoia occidentalis, a conifer closely related to modern redwoods, flourished across the state during this time. Early additions included camels such as Paratylopus and Gentilicamelus and pecora such as Hypertragulus. Later additions included perissodactyls such as Merychippus, Parahippus, Protapirus, and Diceratherium, artiodactyls such as Dromomeryx and Blastomeryx, and proboscids like Gomphotherium and Platybelodon. Rodents including the burrowing beaver Palaeocastor and horned gopher Mylagaulus. Predators in this time period included bear-dogs such as Amphicyon, cat-like nimravids, entelodonts, and early canids such as Cormocyon. Aquatic mammals made their first appearance in Oregon along the early Neogene coast. Fossils from early pinnipeds such Enaliarctos and the primitive walrus Proneotherium have been found in Lincoln County. Kolponomos newportensis, a bear-like aquatic carnivore with features similar to saber-toothed predators, comes from nearby deposits of similar age. Whales such as Aetiocetus and the primitive mysticete Cophocetus oregonensis appear in Oregon's fossil record in this period. Paleontologists believe that animals in these two groups fed on clams and other mollusks, which is consistent with fossil clam beds found in the Coast Range. Global cooling in the late Neogene gave way to glaciation in the Quaternary. Oregon's mountain ranges were covered in large ice caps, although the Cordilleran Ice Sheet did not extend into the state. Glacial erratics can be found across the northern half of the state, including sites such as the Erratic Rock State Natural Site. Pluvial lakes are also common across the state. These include Fossil Lake, which is the source of Oregon's largest Pleistocene fossil assemblage. Included in this assemblage are typical Pleistocene megafauna, including Columbian mammoths, dire wolves, Ice Age bison, camels, the ground sloth Mylodon and the short-faced bear Arctodus (which was previously mistaken for its cousin Arctotherium). The assemblage also includes over 50 species of waterfowl, including grebes, cormorants, swans, gulls, flamingos, herons, and pelicans. Among the bony fish species found in Fossil Lake's assemblage are several salmon species. the McMinnville mammoth, and the Woodburn Teratornis. The Willamette Valley Pleistocene Project has reported the discovery of mammoth tracks, attributable to the ichnotaxon Proboscipeda, near the Yamhill River. A spectacular set of 117 mammoth tracks some 43,000 years old at Fossil Lake, near Christmas Valley, reveal a touching drama of wounded mother and concerned yearlings A 9-meter bear trackway, including tracks of the same size and age as Arctodus has been found near Lakeview. Tectonic activity associated with the Cascadian Subduction Zone continued throughout the Quaternary, leaving evidence of a series of earthquakes and tsunamis in the past 60 thousand years. At the end of the Last Glacial Maximum, collapse of the ice dam surrounding Lake Missoula initiated a series of large-scale floods that inundated much of the state from 19-13 thousand years ago. Around 14 thousand years ago, the Bonneville Flood contributed more floodwaters to many of the same areas. These floods contributed to the modern fertility of the Willamette Valley by transporting soils from the east. Other early sites include an encampment near Bandon dated to around 10,000 years ago and a pair of sandals from Fort Rock Cave dated to around 9,000 years ago. ==History==

Indigenous interpretations Ancient people living near Fossil, Oregon collected fossils as far back as 11,000 years ago and kept them at a dwelling that has since been uncovered by archeologists. Some of the fossils kept there were pierced to be made into jewelry. Five slabs of rock bearing leaf impressions were found neatly stacked in the corner of the site. These and other fossils discovered by Native Americans may have contributed to the development of local myths and lore. Historian Adrienne Mayor cites as an example the Klamath Tribes of the Modoc, who attributed local fossils to water monsters killed by the mythological figure Coyote. Scientific research Professional work Oregon's first paleontologist was Thomas Condon. Condon began collecting in 1861, when a company of soldiers that arrived in Fort Dalles, where Condon served as the Congregational church pastor. The soldiers brought fossil bones and teeth, including a well-preserved rhinoceros jaw, from the John Day fossil beds. When soldiers were dispatched the following year to Harney Valley, near the fossil beds, Condon went along with them and prospected for fossils. He went fossil collecting again in 1863 and discovered rich fossil deposits north of Picture Gorge in the John Day River valley. In the present day, Oregon State University and the University of Oregon both maintain active research programs in paleontology. Oregon State University's Terry Lab, under the supervision of Rebecca Terry, produces research into paleoecology and Quaternary climate change. The University of Oregon's Vertebrate Paleontology Lab, under the supervision of Samantha Hopkins and Edward Davis, focuses on Oregon's extinct mammals. The University of Oregon's paleontology faculty also includes Greg Retallack, who studies fossilized soils. Many of the finds described above were collected, described, and analyzed by researchers in these programs and their predecessors. Amateur work There are several organizations located in Oregon devoted to citizen science initiatives related to paleontology. Among these is the North American Research Group, which was responsible for discovery of the "Mitchell's Monster" plesiosaur and "Bernie" the Jurassic thalattosaurian. Another amateur group is the Willamette Valley Pleistocene Project, which collects from sites in McMinnville, Tualatin, Woodburn, Newberg, and King's Valley. == Notable people ==

• Thomas Condon • Edward Drinker Cope • Othniel Charles Marsh ==Notable locations==

Fossil localities • Astoria Formation • Blue Mountains • Coyote Butte Formation • Curry County • Fossil Lake • Keasey Formation • Nye Formation • Pittsburg Bluff Formation • Wallowa Mountains Protected areas • John Day Fossil Beds National Monument • Paisley Caves Natural history museums • University of Oregon Museum of Natural and Cultural History, Eugene • Thomas Condon Paleontology Center, John Day Fossil Beds National Monument ==See also==