Encrinites are a type of grain-supported bioclastic sedimentary rock in which all or most of the grains are crinoid ossicles. In older literature, the word is sometimes used to refer to individual fossil crinoids, but this usage is obsolete.
Encrinites are a type of grain-supported bioclastic sedimentary rock in which all or most of the grains are crinoid ossicles. In older literature, the word is sometimes used to refer to individual fossil crinoids, but this usage is obsolete.
Encrinites form in areas where disaggregated crinoid skeletal debris becomes concentrated, typically shallow warm euhaline seas. They are therefore very common in the Paleozoic rock record of North America and Eurasia, particularly during the Silurian through Early Devonian and the Early Mississippian age, when high sea levels created widespread epeiric seas. Some encrinites are also known from the Jurassic of North America and Western Europe.
The Cretaceous is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of the entire Phanerozoic. The name is derived from the Latin creta, "chalk", which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation Kreide.
The Jurassic is a geologic period and stratigraphic system that spanned from the end of the Triassic Period 201.3 million years ago (Mya) to the beginning of the Cretaceous Period, approximately 145 Mya. The Jurassic constitutes the middle period of the Mesozoic Era and is named after the Jura Mountains, where limestone strata from the period were first identified.
Crinoids are marine animals that make up the class Crinoidea, one of the classes of the phylum Echinodermata, which also includes the starfish, brittle stars, sea urchins and sea cucumbers. Those crinoids which, in their adult form, are attached to the sea bottom by a stalk are commonly called sea lilies, while the unstalked forms are called feather stars or comatulids, being members of the largest crinoid order, Comatulida.
The Western Interior Seaway was a large inland sea that existed during the mid- to late Cretaceous period as well as the very early Paleogene, splitting the continent of North America into two landmasses, Laramidia to the west and Appalachia to the east. The ancient sea stretched from the Gulf of Mexico and through the middle of the modern-day countries of the United States and Canada, meeting with the Arctic Ocean to the north. At its largest, it was 2,500 feet (760 m) deep, 600 miles (970 km) wide and over 2,000 miles (3,200 km) long.
Ogmore-by-Sea is a seaside village in St Brides Major community in the Vale of Glamorgan, Wales. It lies on the western limit of the Glamorgan Heritage Coast of south Wales. The population in 2011 was 878.
The Sundance Sea was an epeiric sea that existed in North America during the mid-to-late Jurassic Period of the Mesozoic Era. It was an arm of what is now the Arctic Ocean, and extended through what is now western Canada into the central western United States. The sea receded when highlands to the west began to rise.
Pentacrinites is an extinct genus of crinoids that lived from the Hettangian to the Bathonian of Asia, Europe, North America, and New Zealand. Their stems are pentagonal to star-shaped in cross-section and are the most commonly preserved parts. Pentacrinites are commonly found in the Pentacrinites Bed of the Early Jurassic of Lyme Regis, Dorset, England. Pentacrinites can be recognized by the extensions all around the stem, which are long, unbranching, and of increasing length further down, the very small cup and 5 long freely branching arms.
The Mesozoic marine revolution refers to the increase in shell-crushing (durophagous) and boring predation in benthic organisms throughout the Mesozoic era. The term was first coined by Geerat J. Vermeij, who based his work on that of Steven M. Stanley. While initially restricted to the Late Cretaceous, more recent studies have suggested that the beginning of this ecological arms race extends back into the Norian. It is an important transition between the Palaeozoic evolutionary fauna and the Cenozoic evolutionary fauna that occurred throughout the Mesozoic.
Laurentia or the North American Craton is a large continental craton that forms the ancient geological core of North America. Many times in its past, Laurentia has been a separate continent, as it is now in the form of North America, although originally it also included the cratonic areas of Greenland and also the northwestern part of Scotland, known as the Hebridean Terrane. During other times in its past, Laurentia has been part of larger continents and supercontinents and itself consists of many smaller terranes assembled on a network of Early Proterozoic orogenic belts. Small microcontinents and oceanic islands collided with and sutured onto the ever-growing Laurentia, and together formed the stable Precambrian craton seen today.
The Posidonia Shale geologically known as the Sachrang Formation, is an Early Jurassic (Toarcian) geological formation of southwestern and northeast Germany, northern Switzerland, northwestern Austria, southern Luxembourg and the Netherlands, including exceptionally well-preserved complete skeletons of fossil marine fish and reptiles. The Posidonienschiefer, as German paleontologists call it, takes its name from the ubiquitous fossils of the oyster-related bivalve Posidonia bronni that characterize the mollusk faunal component of the formation.
The Brassfield Formation, named by A.F. Foerste in 1906, is a limestone and dolomite formation exposed in Arkansas, Ohio, Kentucky, Indiana, Tennessee and West Virginia in the United States. It is Early Silurian in age and well known for its abundant echinoderms, corals and stromatoporoids. In Ohio, where the unit has escaped dolomitization, the Brassfield is an encrinite biosparite with numerous crinoid species.
Paleontology in Tennessee refers to paleontological research occurring within or conducted by people from the U.S. state of Tennessee. During the early part of the Paleozoic era, Tennessee was covered by a warm, shallow sea. This sea was home to brachiopods, bryozoans, cephalopods, corals, and trilobites. Tennessee is one of the best sources of Early Devonian fossils in North America. During the mid-to-late Carboniferous, the state became a swampy environment, home to a rich variety of plants including ferns and scale trees. A gap in the local rock record spans from the Permian through the Jurassic. During the Cretaceous, the western part of the state was submerged by seawater. The local waters were home to more fossil gastropods than are known from anywhere else in the world. Mosasaurs and sea turtles also inhabited these waters. On land the state was home to dinosaurs. Western Tennessee was still under the sea during the early part of the Cenozoic. Terrestrial portions of the state were swampy. Climate cooled until the Ice Age, when the state was home to Camelops, horses, mammoths, mastodons, and giant ground sloths. The local Yuchi people told myths of giant lizard monsters that may have been inspired by fossils either local or encountered elsewhere. In 1920, after local fossils became a subject of formal scientific study, a significant discovery of a variety of Pleistocene creatures was made near Nashville. The Cretaceous bivalve Pterotrigonia thoracica is the Tennessee state fossil.
Paleontology in Vermont comprises paleontological research occurring within or conducted by people from the U.S. state of Vermont. Fossils are generally uncommon in Vermont. Nevertheless, however, significant finds have been made in the state. Very few fossils are known in Vermont east of the Green Mountains due to the type of rock underlying that area. During the early part of the Paleozoic era, Vermont was covered by a warm, shallow sea that would end up being home to creatures like brachiopods, corals, crinoids, ostracoderms, and trilobites. There are no rocks in the state from the Carboniferous, Permian, Triassic, or Jurassic periods. The few Cretaceous rocks present contain no fossils. The Paleogene and Neogene periods are also absent from the local rock record. During the Ice Age, glaciers scoured the state. At times the state was inundated by seawater, allowing marine mammals to venture in. After the seawater drained away the state was home to mastodons. Local fossils had already attracted scientific attention by the mid-19th century when mastodon remains were found in Rutland County. In 1950 a major Paleozoic invertebrate find occurred. The Pleistocene Beluga whale Delphinapterus leucas is the Vermont state fossil.
Paleontology in Missouri refers to paleontological research occurring within or conducted by people from the U.S. state of Missouri. The geologic column of Missouri spans all of geologic history from the Precambrian to present with the exception of the Permian, Triassic, and Jurassic. Brachiopods are probably the most common fossils in Missouri.
Paleontology in Iowa refers to paleontological research occurring within or conducted by people from the U.S. state of Iowa. The paleozoic fossil record of Iowa spans from the Cambrian to Mississippian. During the early Paleozoic Iowa was covered by a shallow sea that would later be home to creatures like brachiopods, bryozoans, cephalopods, corals, fishes, and trilobites. Later in the Paleozoic, this sea left the state, but a new one covered Iowa during the early Mesozoic. As this sea began to withdraw a new subtropical coastal plain environment which was home to duck-billed dinosaurs spread across the state. Later this plain was submerged by the rise of the Western Interior Seaway, where plesiosaurs lived. The early Cenozoic is missing from the local rock record, but during the Ice Age evidence indicates that glaciers entered the state, which was home to mammoths and mastodons.
Paleontology in Minnesota refers to paleontological research occurring within or conducted by people from the U.S. state of Minnesota. The geologic record of Minnesota spans from Precambrian to recent with the exceptions of major gaps including the Silurian period, the interval from the Middle to Upper Devonian to the Cretaceous, and the Cenozoic. During the Precambrian, Minnesota was covered by an ocean where local bacteria ended up forming banded iron formations and stromatolites. During the early part of the Paleozoic era southern Minnesota was covered by a shallow tropical sea that would come to be home to creatures like brachiopods, bryozoans, massive cephalopods, corals, crinoids, graptolites, and trilobites. The sea withdrew from the state during the Silurian, but returned during the Devonian. However, the rest of the Paleozoic is missing from the local rock record. The Triassic is also missing from the local rock record and Jurassic deposits, while present, lack fossils. Another sea entered the state during the Cretaceous period, this one inhabited by creatures like ammonites and sawfish. Duckbilled dinosaurs roamed the land. The Paleogene and Neogene periods of the ensuing Cenozoic era are also missing from the local rock record, but during the Ice Age evidence points to glacial activity in the state. Woolly mammoths, mastodons, and musk oxen inhabited Minnesota at the time. Local Native Americans interpreted such remains as the bones of the water monster Unktehi. They also told myths about thunder birds that may have been based on Ice Age bird fossils. By the early 19th century, the state's fossil had already attracted the attention of formally trained scientists. Early research included the Cretaceous plant discoveries made by Leo Lesquereux.
The prehistory of the United States comprises the occurrences within regions now part of the United States during the interval of time spanning from the formation of the Earth to the documentation of local history in written form. At the start of the Paleozoic era, what is now "North" America was actually in the southern hemisphere. Marine life flourished in the country's many seas, although terrestrial life had not yet evolved. During the latter part of the Paleozoic, seas were largely replaced by swamps home to amphibians and early reptiles. When the continents had assembled into Pangaea drier conditions prevailed. The evolutionary precursors to mammals dominated the country until a mass extinction event ended their reign.
This list of fossil echinoderms described in 2014 is a list of new taxa of echinoderms of every kind that have been described during the year 2014. The list only includes taxa at the level of genus or species.
Olev Vinn is Estonian paleobiologist and paleontologist.
The geology of North Korea has been studied by the Central Geological Survey of Mineral Resources, rare international research and by inference from South Korea's geology.
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