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Paleontology in Kentucky refers to paleontological research occurring within or conducted by people from the U.S. state of Kentucky. Kentucky's abundance of exposed sedimentary rock makes it an ideal source of fossils. The oldest exposed rocks in Kentucky are of Ordovician age. The geologic column of Kentucky also contains rocks deposited during the ensuing periods until the end of the Pennsylvanian. During this span of time the state was first home to a warm shallow sea home to an abundance and variety of brachiopods, cephalopods, crinoids, and trilobites. During the Devonian, a large reef system formed at what is now the Falls of the Ohio. Swamps covered Kentucky during the ensuing Carboniferous period. Then a gap spans from the start of the Permian to the Pleistocene, although the gap is interrupted by minor deposits of Cretaceous and Eocene rocks. These deposits mainly preserve plant fossils. Ice Age Kentucky was home to short-faced bear, bison, elk, lions, mammoths, mastodons, and giant ground sloths. Local Native Americans interpreted fossils of this age at Big Bone Lick as belonging to ancient monsters killed by benevolent mystical little people. This same fossil deposit would attract attention from major American figures like George Washington, Daniel Boone, and, especially, Thomas Jefferson. Amateur fossil collectors should be aware that they need permission from landowners to prospect legally on private property.〔 Brachiopods are the Kentucky state fossil. ==Prehistory== The oldest exposed rocks in Kentucky are of Ordovician age.〔 At this time Kentucky was covered by a shallow, warm sea. The carbonate rocks of Kentucky deposited during this period are regarded as "world-class" sources of fossils.〔 Marine conditions continued to prevail during the Silurian.〔 Brachiopods are the most common fossil from the period in Kentucky, but bryozoans were also preserved in abundance. Other Silurian life forms of Kentucky included gastropods, pelecypods, cephalopods, crinoids, trilobites, and a variety of corals.〔 The seas of Kentucky were still present during the ensuing Devonian. No fishes are known from the Devonian deposits in Kentucky, in fact fossils of this age are generally uncommon.〔 However, the fossil reef located at the Falls of the Ohio is one of the best preserved and most famous in North America.〔 By the late Devonian, local dissolved oxygen levels dropped precipitously.〔 Mississippian life left an abundant fossil record in Kentucky. Life of that time period included abundant bryozoans and corals, a diverse variety of crinoids and some conodonts.〔 The Mississippian carbonates of southern Kentucky are also very rich in fossils.〔 The rich flora of Kentucky's Late Mississippian swamps left behind many fossils.〔 Other aquatic fossils of Kentucky include the bones, scales, and teeth of fishes, including shark remains.〔 During the Pennsylvanian Kentucky's environment tended to be drier than it was earlier in the Paleozoic, with both land and sea fossils being represented in rocks of this age.〔 The state's Pennsylvanian marine life included brachiopods, pelecypods, gastropods, cephalopods, anthozoans (corals and their relatives), echinoids, bryozoans, and crustaceans.〔 The state's coal beds are the remnants of ancient peat swamps. Fossil tree trunks and other plant fossils are often found in the rocks above coal beds.〔 The ancient swamps of Pennsylvanian Kentucky left behind many fossils.〔 A fossil trackway preserved in McCreary County is among the oldest fossil evidence for the existence of reptiles.〔 The interval spanning the Permian Period and Mesozoic Era are almost completely absent from the state's rock record.〔 Little is known about Kentucky's Permian history except that the sea withdrew to the far western corner of the state during this period.〔 There are also a few Cretaceous deposits in the state formed in both marine and terrestrial environments.〔 Very few fossils are known from the Cretaceous life of Kentucky.〔 Among these scarce remains, however, were plants.〔 Dinosaur fossils have not been found in Kentucky.〔 Like the Cretaceous, the geologic record of Kentucky contains deposits left on both land and sea during the Tertiary.〔 Also like the Cretaceous, Kentucky preserves plant fossils from this age.〔 Kentucky's Tertiary flora left behind fossil fruits, cones, flower petals and stems in places like Ballard, Graves, and Fulton Counties. The Wickliffe area of Ballard County has been the source of at least 27 new plant species from that time period. The presence of termites in the state at this time is attested to by the existence of a single fossil wing preserved 2.5 miles south of Columbus. The Tertiary marine life of Kentucky included marine mollusks. Fish were also present and sometimes their scales would fossilize.〔Pliocene to Pleistocene invertebrate fossils are common in Fayette County.〔 Glaciers intruded into the northernmost part of the state.〔 The vertebrates from this interval of time outside of Big Bone Lick include giant beavers in eastern Kentucky and tapirs in Fayette County.〔 Other local wildlife included short-faced bear, bison, elk, lions, mammoths, mastodons, and giant ground sloths. Fossils from animals like these are widespread throughout the state and preserved in a variety of contexts. Among the types of deposits preserving mammals of this age are caves, ponds, river gravel, salt licks, sinkholes, and mineral springs.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Paleontology in Kentucky」の詳細全文を読む スポンサード リンク
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