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Trimerellidae
Trimerellida is an Extinction, extinct Order (biology), order of Craniata (brachiopod), craniate brachiopods, containing the sole Superfamily (biology), superfamily Trimerelloidea and the Family (biology), families Adensuidae, Trimerellidae, and Ussuniidae. Trimerellidae was a widespread family of warm-water brachiopods ranging from the Middle Ordovician ("Llandeilo" / Darriwilian) to the late Silurian (Ludlow epoch, Ludlow). Adensuidae and Ussuniidae are monogeneric families restricted to the Ordovician of Kazakhstan. Most individuals were free-living, though some (namely Australian populations of the genus ''Eodinobolus'') clustered into large congregations similar to modern Oyster reef, oyster reefs. Evolution Trimerellides probably originated from tropical Island arc, island arcs in the region of Kazakhstania (present-day Kazakhstan) during the "Llandeilo" (late Darriwilian stage). By the late Sandbian and early Katian stages, many dispersed eastward to nearby regions equiva ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Craniiforma
Craniata is a class of brachiopods originating in the Cambrian period and still extant today. It is the only class within the subphylum Craniiformea, one of three major subphyla of brachiopods alongside linguliforms and rhynchonelliforms. Craniata is divided into three orders: the extinct Craniopsida and Trimerellida, and the living Craniida, which provides most information on their biology. Living members of the class have shells which are composed of calcite, though some extinct forms my have aragonite shells. The shells are inarticulate (lack a hinge with distinct tooth-and-socket connections) and are usually rounded in outline. There is no pedicle; the rear edge of the body cavity is a smooth and flat wall perforated by the anus. This class of brachiopods has an unsupported lophophore The lophophore () is a characteristic feeding organ possessed by four major groups of animals: the Brachiopoda, Bryozoa, Hyolitha, and Phoronida, which collectively constitute the proto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemism
Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can also be referred to as an ''endemism'' or, in scientific literature, as an ''endemite''. Similarly, many species found in the Western ghats of India are examples of endemism. Endemism is an important concept in conservation biology for measuring biodiversity in a particular place and evaluating the risk of extinction for species. Endemism is also of interest in evolutionary biology, because it provides clues about how changes in the environment cause species to undergo range shifts (potentially expanding their range into a larger area or b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siberia (continent)
Siberia, also known as Siberian Craton, Angaraland (or simply Angara) and Angarida, is an ancient craton in the heart of Siberia. Today forming the Central Siberian Plateau, it formed an independent landmass prior to its fusion into Pangea during the Late Carboniferous-Permian. The Verkhoyansk Sea, a passive continental margin, was fringing the Siberian Craton to the east in what is now the East Siberian Lowland. Angaraland was named in the 1880s by Austrian geologist Eduard Suess who erroneously believed that in the Paleozoic Era there were two large continents in the Northern Hemisphere: "Atlantis", which was North America connected to Europe via a peninsula (Greenland and Iceland), and "Angara-land", which would have been eastern Asia, named after the Angara River in Siberia. Precambrian history About 2.5 billion years ago (in the Siderian Period), Siberia was part of a continent called Arctica, along with the Canadian Shield. Around 1.1 billion years ago (in the Steni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baltica
Baltica is a paleocontinent that formed in the Paleoproterozoic and now constitutes northwestern Eurasia, or Europe north of the Trans-European Suture Zone and west of the Ural Mountains. The thick core of Baltica, the East European Craton, is more than three billion years old and formed part of the Rodinia supercontinent at 1 . Tectonic history Baltica formed at 2.0–1.7 Ga by the collision of three Archaean-Proterozoic continental blocks: Fennoscandia (including the exposed Baltic Shield), Sarmatia ( Ukrainian Shield and Voronezh Massif), and Volgo-Uralia (covered by younger deposits). Sarmatia and Volgo-Uralia formed a proto-craton (sometimes called "Proto-Baltica") at c. 2.0 Ga which collided with Fennoscandia c. 1.8–1.7 Ga. The sutures between these three blocks were reactivated during the Mesoproterozoic and Neoproterozoic. Between 750 and 600 million years ago, Baltica and Laurentia rotated clockwise together and drifted away from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gondwana
Gondwana ( ; ) was a large landmass, sometimes referred to as a supercontinent. The remnants of Gondwana make up around two-thirds of today's continental area, including South America, Africa, Antarctica, Australia (continent), Australia, Zealandia, Arabian Peninsula, Arabia, and the Indian subcontinent. Gondwana was formed by the Accretion (geology), accretion of several cratons (large stable blocks of the Earth's crust), beginning with the East African Orogeny, the collision of India and Geography of Madagascar, Madagascar with East Africa, and culminating in with the overlapping Brasiliano orogeny, Brasiliano and Kuunga orogeny, Kuunga orogenies, the collision of South America with Africa, and the addition of Australia and Antarctica, respectively. Eventually, Gondwana became the largest piece of continental crust of the Paleozoic Era, covering an area of some , about one-fifth of the Earth's surface. It fused with Laurasia during the Carboniferous to form Pan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laurentia
Laurentia or the North American craton is a large continental craton that forms the Geology of North America, 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 the Hebridean terrane in northwest Scotland. During other times in its past, Laurentia has been part of larger continents and supercontinents and consists of many smaller terranes assembled on a network of early Proterozoic Orogenic belt, orogenic belts. Small microcontinents and oceanic islands collided with and Suture (geology), sutured onto the ever-growing Laurentia, and together formed the stable Precambrian craton seen today. Etymology The craton is named after the Laurentian Shield, through the Laurentian Mountains, which received their name from the St. Lawrence River, named after Saint Lawrence of Rome. Interior platform In eastern and centra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South China Craton
The South China Craton or South China Block is one of the Precambrian continental blocks in China. It is traditionally divided into the Yangtze Plate, Yangtze Block in the NW and the Cathaysia, Cathaysia Block in the SE. The Jiangshan–Shaoxing Fault represents the Suture (geology), suture boundary between the two sub-blocks. Recent study suggests that the South China Block possibly has one more sub-block which is named the Tolo Terrane. The oldest rocks in the South China Block occur within the Huangling Anticline, Kongling Complex, which yields Uranium–lead dating, zircon U–Pb ages of 3.3–2.9 Ga. There are three important reasons to study the South China Block. First, South China hosts a great deal of Rare-earth element, rare-earth element (REE) ores. Second, the South China Block is a key component of the Rodinia, Rodinia supercontinent. Therefore, such study helps us understand more about the supercontinent cycle. Third, almost all major known clades of Triassic marine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Katian
The Katian is the second stage of the Upper Ordovician. It is preceded by the Sandbian and succeeded by the Hirnantian Stage. The Katian began million years ago and lasted for about 7.6 million years until the beginning of the Hirnantian million years ago. During the Katian the climate cooled which started the Late Ordovician glaciation. Naming The name Katian is derived from Katy Lake ( Atoka County, Oklahoma, United States). GSSP The GSSP of the Katian Stage is the Black Knob Ridge Section in southeastern Oklahoma (United States). It is an outcrop of the Womble Shale and the Bigfork Chert, the latter containing the lower boundary of the Katian. The lower boundary is defined as the first appearance datum of the graptolite Graptolites are a group of colonial animals, members of the subclass Graptolithina within the class Pterobranchia. These filter-feeding organisms are known chiefly from fossils found from the Middle Cambrian ( Miaolingian, Wuliuan) through t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
