Paul Heinrich Gerhard Möhring was a German physician and zoologist. He studied medicine in Danzig and Wittenberg, following graduation, he settled as a general practitioner in his hometown of Jever. Möhring was a physician to the Prince of Anhalt. In 1752 he published Avium Genera, an early attempt to classify bird species, which divided birds into four classes and shows the beginnings of the modern groupings. During his long career, he maintained correspondence with Albrecht von Haller, Lorenz Heister, Carl Linnaeus, Hans Sloane and Paul Gottlieb Werlhof; the plant genus. "De inflammationis sanguineae theoria mechanica", 1733. "Historiae medicinales", 1739. "Avium genera", 1752. Geslachten der Vogelen 1758. IPNI List of plants described by Paul Möhring
The Ordovician is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.2 million years from the end of the Cambrian Period 485.4 million years ago to the start of the Silurian Period 443.8 Mya. The Ordovician, named after the Celtic tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same rock beds in northern Wales into the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed strata were different from those of either the Cambrian or the Silurian systems, placed them in a system of their own; the Ordovician received international approval in 1960, when it was adopted as an official period of the Paleozoic Era by the International Geological Congress. Life continued to flourish during the Ordovician as it did in the earlier Cambrian period, although the end of the period was marked by the Ordovician–Silurian extinction events.
Invertebrates, namely molluscs and arthropods, dominated the oceans. The Great Ordovician Biodiversification Event increased the diversity of life. Fish, the world's first true vertebrates, continued to evolve, those with jaws may have first appeared late in the period. Life had yet to diversify on land. About 100 times as many meteorites struck the Earth per year during the Ordovician compared with today; the Ordovician Period began with a major extinction called the Cambrian–Ordovician extinction event, about 485.4 Mya. It lasted for about 42 million years and ended with the Ordovician–Silurian extinction events, about 443.8 Mya which wiped out 60% of marine genera. The dates given are recent radiometric dates and vary from those found in other sources; this second period of the Paleozoic era created abundant fossils that became major petroleum and gas reservoirs. The boundary chosen for the beginning of both the Ordovician Period and the Tremadocian stage is significant, it correlates well with the occurrence of widespread graptolite and trilobite species.
The base of the Tremadocian allows scientists to relate these species not only to each other, but to species that occur with them in other areas. This makes it easier to place many more species in time relative to the beginning of the Ordovician Period. A number of regional terms have been used to subdivide the Ordovician Period. In 2008, the ICS erected a formal international system of subdivisions. There exist Baltoscandic, Siberian, North American, Chinese Mediterranean and North-Gondwanan regional stratigraphic schemes; the Ordovician Period in Britain was traditionally broken into Early and Late epochs. The corresponding rocks of the Ordovician System are referred to as coming from the Lower, Middle, or Upper part of the column; the faunal stages from youngest to oldest are: Late Ordovician Hirnantian/Gamach Rawtheyan/Richmond Cautleyan/Richmond Pusgillian/Maysville/Richmond Middle Ordovician Trenton Onnian/Maysville/Eden Actonian/Eden Marshbrookian/Sherman Longvillian/Sherman Soudleyan/Kirkfield Harnagian/Rockland Costonian/Black River Chazy Llandeilo Whiterock Llanvirn Early Ordovician Cassinian Arenig/Jefferson/Castleman Tremadoc/Deming/Gaconadian The Tremadoc corresponds to the Tremadocian.
The Floian corresponds to the lower Arenig. The Llanvirn occupies the rest of the Darriwilian, terminates with it at the base of the Late Ordovician; the Sandbian represents the first half of the Caradoc. During the Ordovician, the southern continents were collected into Gondwana. Gondwana started the period in equatorial latitudes and, as the period progressed, drifted toward the South Pole. Early in the Ordovician, the continents of Laurentia and Baltica were still independent continents, but Baltica began to move towards Laurentia in the period, causing the Iapetus Ocean between them to shrink; the small continent Avalonia separated from Gondwana and began to move north towards Baltica and Laurentia, opening the Rheic Ocean between Gondwana and Avalonia. The Taconic orogeny, a major mountain-building episode, was well under way in Cambrian times. In the early and middle Ordovician, temperatures were mild, but at the beginning of the Late Ordovician, from 460 to 450 Ma, volcanoes along the margin of the Iapetus Ocean spewed massive amounts of carbon dioxide, a greenhouse gas, into the atmosphere, turning the planet into a hothouse.
Sea levels were high, but as Gondwana moved south, ice accumulated into glaciers and sea levels dropped. At first, low-lying sea beds increased diversity, but glaciation led to mass extinctions as the seas drained and continental shelves became dry land. During the Ordovician, in fact during the Tremadocian, marine transgressions worldwide were the greatest for which evidence is preserved; these volcanic island arcs collided with proto North America to form the Appalachian mountains. By the end of the Late Ordovician the volcanic emissions had stopped. Gondwana had by that time neared the South Pole and was glaciated
The emu is the second-largest living bird by height, after its ratite relative, the ostrich. It is endemic to Australia where it is the largest native bird and the only extant member of the genus Dromaius; the emu's range covers most of mainland Australia, but the Tasmanian, Kangaroo Island and King Island subspecies became extinct after the European settlement of Australia in 1788. The bird is sufficiently common for it to be rated as a least-concern species by the International Union for Conservation of Nature. Emus are soft-feathered, flightless birds with long necks and legs, can reach up to 1.9 metres in height. Emus can travel great distances, when necessary can sprint at 50 km/h, they take in copious amounts of water when the opportunity arises. Breeding takes place in May and June, fighting among females for a mate is common. Females can lay several clutches of eggs in one season; the male does the incubation. The eggs hatch after around eight weeks, the young are nurtured by their fathers.
They reach full size after around six months, but can remain as a family unit until the next breeding season. The emu is an important cultural icon of Australia, appearing on the coat of various coins; the bird features prominently in Indigenous Australian mythology. Emus were first reported as having been seen by Europeans when explorers visited the western coast of Australia in 1696; the birds were known on the eastern coast before 1788. The birds were first mentioned under the name of the "New Holland cassowary" in Arthur Phillip's Voyage to Botany Bay, published in 1789 with the following description: This is a species differing in many particulars from that known, is a much larger bird, standing higher on its legs and having the neck longer than in the common one. Total length seven feet two inches; the bill is not different from that of the common Cassowary. The plumage in general consists of a mixture of brown and grey, the feathers are somewhat curled or bent at the ends in the natural state: the wings are so short as to be useless for flight, indeed, are scarcely to be distinguished from the rest of the plumage, were it not for their standing out a little.
The long spines which are seen in the wings of the common sort, are in this not observable,—nor is there any appearance of a tail. The legs are stout, formed much as in the Galeated Cassowary, with the addition of their being jagged or sawed the whole of their length at the back part; the species was named by ornithologist John Latham in 1790 based on a specimen from the Sydney area of Australia, a country, known as New Holland at the time. He collaborated on Phillip's book and provided the first descriptions of, names for, many Australian bird species. In his original 1816 description of the emu, the French ornithologist Louis Jean Pierre Vieillot used two generic names, first Dromiceius and Dromaius, it has been a point of contention since as to which name should be used. Most modern publications, including those of the Australian government, use Dromaius, with Dromiceius mentioned as an alternative spelling; the etymology of the common name "emu" is uncertain, but is thought to have come from an Arabic word for large bird, used by Portuguese explorers to describe the related cassowary in Australia and New Guinea.
Another theory is that it comes from the word "ema", used in Portuguese to denote a large bird akin to an ostrich or crane. In Victoria, some terms for the emu were Barrimal in the Dja Dja Wurrung language, myoure in Gunai, courn in Jardwadjali; the birds were known as murawung or birabayin to the local Eora and Darug inhabitants of the Sydney basin. The emu was long classified, with its closest relatives the cassowaries, in the family Casuariidae, part of the ratite order Struthioniformes. However, an alternate classification was proposed in 2014 by Mitchell et al. based on analysis of mitochondrial DNA. This splits off the Casuariidae into their own order, the Casuariformes, includes only the cassowaries in the family Casuariidae, placing the emus in their own family, Dromaiidae; the cladogram shown below is from their study. Two different Dromaius species were present in Australia at the time of European settlement, one additional species is known from fossil remains; the insular dwarf emus, D. n. baudinianus and D. n. minor present on Kangaroo Island and King Island both became extinct shortly after the arrival of Europeans.
D. n. diemenensis, another insular dwarf emu from Tasmania, became extinct around 1865. However, the mainland subspecies, D. n. novaehollandiae, remains common. The population of these birds varies from decade to de
In zoological nomenclature, a type species is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e. the species that contains the biological type specimen. A similar concept is used for suprageneric groups called a type genus. In botanical nomenclature, these terms have no formal standing under the code of nomenclature, but are sometimes borrowed from zoological nomenclature. In botany, the type of a genus name is a specimen, the type of a species name; the species name that has that type can be referred to as the type of the genus name. Names of genus and family ranks, the various subdivisions of those ranks, some higher-rank names based on genus names, have such types. In bacteriology, a type species is assigned for each genus; every named genus or subgenus in zoology, whether or not recognized as valid, is theoretically associated with a type species. In practice, there is a backlog of untypified names defined in older publications when it was not required to specify a type.
A type species is both a concept and a practical system, used in the classification and nomenclature of animals. The "type species" represents the reference species and thus "definition" for a particular genus name. Whenever a taxon containing multiple species must be divided into more than one genus, the type species automatically assigns the name of the original taxon to one of the resulting new taxa, the one that includes the type species; the term "type species" is regulated in zoological nomenclature by article 42.3 of the International Code of Zoological Nomenclature, which defines a type species as the name-bearing type of the name of a genus or subgenus. In the Glossary, type species is defined as The nominal species, the name-bearing type of a nominal genus or subgenus; the type species permanently attaches a formal name to a genus by providing just one species within that genus to which the genus name is permanently linked. The species name in turn is fixed, to a type specimen. For example, the type species for the land snail genus Monacha is Helix cartusiana, the name under which the species was first described, known as Monacha cartusiana when placed in the genus Monacha.
That genus is placed within the family Hygromiidae. The type genus for that family is the genus Hygromia; the concept of the type species in zoology was introduced by Pierre André Latreille. The International Code of Zoological Nomenclature states that the original name of the type species should always be cited, it gives an example in Article 67.1. Astacus marinus Fabricius, 1775 was designated as the type species of the genus Homarus, thus giving it the name Homarus marinus. However, the type species of Homarus should always be cited using its original name, i.e. Astacus marinus Fabricius, 1775. Although the International Code of Nomenclature for algae and plants does not contain the same explicit statement, examples make it clear that the original name is used, so that the "type species" of a genus name need not have a name within that genus, thus in Article 10, Ex. 3, the type of the genus name Elodes is quoted as the type of the species name Hypericum aegypticum, not as the type of the species name Elodes aegyptica.
Glossary of scientific naming Genetypes – genetic sequence data from type specimens. Holotype Paratype Principle of Typification Type Type genus
10th edition of Systema Naturae
The 10th edition of Systema Naturae is a book written by Swedish naturalist Carolus Linnaeus and published in two volumes in 1758 and 1759, which marks the starting point of zoological nomenclature. In it, Linnaeus introduced binomial nomenclature for animals, something he had done for plants in his 1753 publication of Species Plantarum. Before 1758, most biological catalogues had used polynomial names for the taxa included, including earlier editions of Systema Naturae; the first work to apply binomial nomenclature across the animal kingdom was the 10th edition of Systema Naturae. The International Commission on Zoological Nomenclature therefore chose 1 January 1758 as the "starting point" for zoological nomenclature, asserted that the 10th edition of Systema Naturae was to be treated as if published on that date. Names published before that date are unavailable if they would otherwise satisfy the rules; the only work which takes priority over the 10th edition is Carl Alexander Clerck's Svenska Spindlar or Aranei Suecici, published in 1757, but is to be treated as if published on January 1, 1758.
During Linnaeus' lifetime, Systema Naturae was under continuous revision. Progress was incorporated into ever-expanding editions; the Animal Kingdom: Animals enjoy sensation by means of a living organization, animated by a medullary substance. They have members for the different purposes of life, they all originate from an egg. Their external and internal structure; the list has been broken down into the original six classes Linnaeus described for animals. These classes were created by studying the internal anatomy, as seen in his key: Heart with 2 auricles, 2 ventricles. Warm, red blood Viviparous: Mammalia Oviparous: Aves Heart with 1 auricle, 1 ventricle. Cold, red blood Lungs voluntary: Amphibia External gills: Pisces Heart with 1 auricle, 0 ventricles. Cold, pus-like blood Have antennae: Insecta Have tentacles: VermesBy current standards Pisces and Vermes are informal groupings, Insecta contained arachnids and crustaceans, one order of Amphibia comprised sharks and sturgeons. Linnaeus described mammals as: Animals.
In external and internal structure they resemble man: most of them are quadrupeds. The largest, though fewest in number, inhabit the ocean. Linnaeus divided the mammals based upon the number and structure of their teeth, into the following orders and genera: Primates: Homo, Lemur & Vespertilio Bruta: Elephas, Bradypus, Myrmecophaga & Manis Ferae: Phoca, Felis, Mustela & Ursus Bestiae: Sus, Erinaceus, Sorex & Didelphis Glires: Rhinoceros, Lepus, Mus & Sciurus Pecora: Camelus, Cervus, Ovis & Bos Belluae: Equus & Hippopotamus Cete: Monodon, Physeter & Delphinus Linnaeus described birds as: A beautiful and cheerful portion of created nature consisting of animals having a body covered with feathers and down, they are areal, vocal and light, destitute of external ears, teeth, womb, epiglottis, corpus callosum and its arch, diaphragm. Linnaeus divided the birds based upon the characters of the bill and feet, into the following 6 orders and 63 genera: Accipitres: Vultur, Strix & Lanius Picae: Psittacus, Buceros, Corvus, Gracula, Cuculus, Picus, Alcedo, Upupa, Certhia & Trochilus Anseres: Anas, Alca, Diomedea, Phaethon, Larus, Sterna & Rhyncops Grallae: Phoenicopterus, Mycteria & Tantulus, Scolopax, Charadrius, Haematopus, Rallus, Otis & Struthio Gallinae: Pavo, Crax, Phasianus & Tetrao Passeres: Columba, Sturnus, Loxia (cardina
Rhea is a character in Greek mythology, the Titaness daughter of the earth goddess Gaia and the sky god Uranus as well as sister and wife to Cronus. In early traditions, she is known as "the mother of gods" and therefore is associated with Gaia and Cybele, who have similar functions; the classical Greeks saw her as the mother of the Olympian gods and goddesses, but not as an Olympian goddess in her own right. The Romans identified her with Magna Mater, the Goddess Ops. Most ancient etymologists derived Rhea by metathesis from ἔρα "ground", although a tradition embodied in Plato and in Chrysippus connected the word with ῥέω, "flow", "discharge", what LSJ supports. Alternatively, the name Rhea may be connected with words for the pomegranate, ῥόα ῥοιά; the name Rhea may derive from a pre-Greek or Minoan source. Graves suggested that Rhea's name is a variant of Era,'earth'. According to Hesiod, Cronus sired six children by Rhea: Hestia, Hera, Hades and Zeus in that order; the philosopher Plato recounts that Rhea and Phorcys were the eldest children of Oceanus and Tethys.
Gaia and Uranus told Cronus that just as he had overthrown his own father, he was destined to be overcome by his own child. Rhea and Gaia devised a plan to save the last of them, Zeus. Rhea gave birth to Zeus in a cavern on the island of Crete, gave Cronus a stone wrapped in swaddling clothes, which he promptly swallowed, her attendants, the warrior-like Kouretes and Dactyls, acted as a bodyguard for the infant Zeus, helping to conceal his whereabouts from his father. In some accounts, by the will of Rhea a golden dog guarded a goat which offered her udder and gave nourishment to the infant Zeus. On, Zeus changed the goat into an immortal among the stars while the golden dog that guarded the sacred spot in Crete was stolen by Pandareus. Rhea had "no strong local cult or identifiable activity under her control", she was worshiped on the island of Crete, identified in mythology as the site of Zeus's infancy and upbringing. Her cults employed rhythmic, raucous chants and dances, accompanied by the tympanon, to provoke a religious ecstasy.
Her priests impersonated her mythical attendants, the Curetes and Dactyls, with a clashing of bronze shields and cymbals. The tympanon's use in Rhea's rites may have been the source for its use in Cybele's – in historical times, the resemblances between the two goddesses were so marked that some Greeks regarded Cybele as their own Rhea, who had deserted her original home on Mount Ida in Crete and fled to Mount Ida in the wilds of Phrygia to escape Cronus. A reverse view was expressed by Virgil, it is true that cultural contacts with the mainland brought Cybele to Crete, where she was transformed into Rhea or identified with an existing local goddess and her rites. Rhea was referred to in ancient times by the title Meter Theon and there where several temples around Ancient Greece dedicated to her under that name. Pausanias mentioned temples dedicated to Rhea under the name Meter Theon in Anagyros in Attika, Megalopolis in Arkadia, on the Acropolis of Ancient Corinth, in the district of Keramaikos in Athens, where the statue was made by Pheidias.
In Sparta there was further more a sanctuary to the Meter Megale. Olympia had both an altar as well as a temple to the Meter Theon: "A temple of no great size in the Doric style they have called down to the present day Metroion, keeping its ancient name. No image lies in it of the Meter Theon, but there stand in it statues of Roman emperors."Her temple in Akriai, Lakedaimon was said to be her oldest sanctuary in Peloponessos: "Well worth seeing here are a temple and marble image of the Meter Theon. The people of Akriai say that this is the oldest sanctuary of this goddess in the Peloponessos."Statues of her were standing in the sanctuaries of other gods and in other places, such as a statue of Parian marble by Damophon in Messene. The scene in which Rhea gave Chronos a stone in the place of Zeus after his birth was assigned to have taken place on Petrakhos Mountain in Arcadia as well as on Mount Thaumasios in Arcadia, both of which were holy places: "Mount Thaumasios lies beyond the river Maloitas, the Methydrians hold that when Rhea was pregnant with Zeus, she came to this mountain and enlisted as her allies, in case Kronos should attack her and his few Gigantes.
They allow that she gave birth to her son on some part of Mount Lykaios, but they claim that here Kronos was deceived, here took place the substitution of a stone for the child, spoken of in the Greek legend. On the summit of the mountain is Rhea's Cave, into which no human beings may enter save only the women who are sacred to the goddess."The center of the worship of Rhea was however on Crete, where the Ida Mountain was said to be the place of the birth of Zeus. There was a "House of Rhea" in Knossos: "The Titanes had their dwelling in the land about Knosos, at the place where to this day men point out foundations of a house of Rhea and a cypress grove, consecrated to her from ancient times."Upon the Ida Mountain, there was a cave sacred to Rhea: "In Crete there is said to be a sacred cave full of bees. In it, as storytellers say, Rhea gave birth to Zeus. At the appointed time each year a great blaze is seen to come out of the cave, their story goes
The Pleistocene is the geological epoch which lasted from about 2,588,000 to 11,700 years ago, spanning the world's most recent period of repeated glaciations. The end of the Pleistocene corresponds with the end of the last glacial period and with the end of the Paleolithic age used in archaeology; the Pleistocene is the first epoch of the Quaternary Period or sixth epoch of the Cenozoic Era. In the ICS timescale, the Pleistocene is divided into four stages or ages, the Gelasian, Middle Pleistocene and Upper Pleistocene. In addition to this international subdivision, various regional subdivisions are used. Before a change confirmed in 2009 by the International Union of Geological Sciences, the time boundary between the Pleistocene and the preceding Pliocene was regarded as being at 1.806 million years Before Present, as opposed to the accepted 2.588 million years BP: publications from the preceding years may use either definition of the period. Charles Lyell introduced the term "Pleistocene" in 1839 to describe strata in Sicily that had at least 70% of their molluscan fauna still living today.
This distinguished it from the older Pliocene epoch, which Lyell had thought to be the youngest fossil rock layer. He constructed the name "Pleistocene" from the Greek πλεῖστος, pleīstos, "most", καινός, kainós, "new"; the Pleistocene has been dated from 2.588 million to 11,700 years BP with the end date expressed in radiocarbon years as 10,000 carbon-14 years BP. It covers most of the latest period of repeated glaciation, up to and including the Younger Dryas cold spell; the end of the Younger Dryas has been dated to about 9640 BC. The end of the Younger Dryas is the official start of the current Holocene Epoch. Although it is considered an epoch, the Holocene is not different from previous interglacial intervals within the Pleistocene, it was not until after the development of radiocarbon dating, that Pleistocene archaeological excavations shifted to stratified caves and rock-shelters as opposed to open-air river-terrace sites. In 2009 the International Union of Geological Sciences confirmed a change in time period for the Pleistocene, changing the start date from 1.806 to 2.588 million years BP, accepted the base of the Gelasian as the base of the Pleistocene, namely the base of the Monte San Nicola GSSP.
The IUGS has yet to approve a type section, Global Boundary Stratotype Section and Point, for the upper Pleistocene/Holocene boundary. The proposed section is the North Greenland Ice Core Project ice core 75° 06' N 42° 18' W; the lower boundary of the Pleistocene Series is formally defined magnetostratigraphically as the base of the Matuyama chronozone, isotopic stage 103. Above this point there are notable extinctions of the calcareous nanofossils: Discoaster pentaradiatus and Discoaster surculus; the Pleistocene covers the recent period of repeated glaciations. The name Plio-Pleistocene has, in the past, been used to mean the last ice age; the revised definition of the Quaternary, by pushing back the start date of the Pleistocene to 2.58 Ma, results in the inclusion of all the recent repeated glaciations within the Pleistocene. The modern continents were at their present positions during the Pleistocene, the plates upon which they sit having moved no more than 100 km relative to each other since the beginning of the period.
According to Mark Lynas, the Pleistocene's overall climate could be characterized as a continuous El Niño with trade winds in the south Pacific weakening or heading east, warm air rising near Peru, warm water spreading from the west Pacific and the Indian Ocean to the east Pacific, other El Niño markers. Pleistocene climate was marked by repeated glacial cycles in which continental glaciers pushed to the 40th parallel in some places, it is estimated. In addition, a zone of permafrost stretched southward from the edge of the glacial sheet, a few hundred kilometres in North America, several hundred in Eurasia; the mean annual temperature at the edge of the ice was −6 °C. Each glacial advance tied up huge volumes of water in continental ice sheets 1,500 to 3,000 metres thick, resulting in temporary sea-level drops of 100 metres or more over the entire surface of the Earth. During interglacial times, such as at present, drowned coastlines were common, mitigated by isostatic or other emergent motion of some regions.
The effects of glaciation were global. Antarctica was ice-bound throughout the Pleistocene as well as the preceding Pliocene; the Andes were covered in the south by the Patagonian ice cap. There were glaciers in New Tasmania; the current decaying glaciers of Mount Kenya, Mount Kilimanjaro, the Ruwenzori Range in east and central Africa were larger. Glaciers existed to the west in the Atlas mountains. In the northern hemisphere, many glaciers fused into one; the Cordilleran ice sheet covered the North American northwest. The Fenno-Scandian ice sheet rested including much of Great Britain. Scattered domes stretched across Siberi