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2020 In Paleontology
Plants Sponges Cnidarians New taxa Research * Revision of tabulate-like fossils from before the latest Middle Ordovician is published by Elias, Lee & Pratt (2020), who reject the interpretation of these fossils as true tabulate corals. * Drake, Whitelegge & Jacobs (2020) report the first recovery, sequencing, and identification of fossil biomineral proteins from a Pleistocene fossil invertebrate (the stony coral ''Orbicella annularis''). Arthropods Bryozoans Brachiopods New taxa Research * A study on the mode of life of Paleozoic strophomenatans is published by Stanley (2020), who argues that nearly all strophomenatans lived infaunally. * A study on the paleobiogeography of Early−Middle Devonian (Pragian−Eifelian) brachiopods from West Gondwana, aiming to determine any potential controls that may have driven bioregionalization, is published by Penn-Clarke & Harper (2020). * A study on the phylogenetic relationships and ecomorphologic diversification of Mesozoi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hirnantian
The Hirnantian is the final internationally recognized stage of the Ordovician Period of the Paleozoic Era. It was of short duration, lasting about 1.4 million years, from to Ma (million years ago). The early part of the Hirnantian was characterized by cold temperatures, major glaciation, and a severe drop in sea level. In the latter part of the Hirnantian, temperatures rose, the glaciers melted, and sea level returned to the same or to a slightly higher level than it had been prior to the glaciation. Most scientists believe that this climatic oscillation caused the major extinction event that took place during this time. In fact, the Hirnantian (also known as the End Ordovician and the Ordovician-Silurian) mass extinction event represents the second largest such event in geologic history. Approximately 85% of marine (sea-dwelling) species died. Only the End Permian mass extinction was larger. Unlike many smaller extinction events, however, the long-term consequences of the E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Langhian
The Langhian is, in the ICS geologic timescale, an age or stage in the middle Miocene Epoch/Series. It spans the time between 15.97 ± 0.05 Ma and 13.65 ± 0.05 Ma (million years ago) during the Middle Miocene.GeoWhen (2007) The Langhian was a continuing warming period defined by Lorenzo Pareto in 1865, it was originally established in the Langhe area north of Ceva in northern Italy, hence the name. The Langhian is preceded by the Burdigalian and followed by the Serravallian Stage. Stratigraphic definition The base of the Langhian is defined by the first appearance of foraminifer species ''Praeorbulina glomerosa'' and is also coeval with the top of magnetic chronozone C5Cn.1n. A GSSP for the Langhian Stage was not yet established in 2009. The top of the Langhian Stage (the base of the Serravallian Stage) is at the first occurrence of fossils of the nanoplankton species ''Sphenolithus heteromorphus'' and is located in magnetic chronozone C5ABr. The Langhian is coeval with the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene is preceded by the Oligocene and is followed by the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by a single distinct global event but consist rather of regionally defined boundaries between the warmer Oligocene and the cooler Pliocene Epoch. During the Early Miocene, the Arabian Peninsula collided with Eurasia, severing the connection between the Mediterranean and Indian Ocean, and allowing a faunal interchange to occur between Eurasia and Africa, including the dispersal of proboscideans into Eurasia. During the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alveopora Kumadai
''Alveopora'' is a genus of colonial stony corals in the family Acroporidae. Members of this genus are native to the Indo-Pacific region and are often found on reef slopes in turbid water. They are generally uncommon. Characteristics ''Alveopora'' has a very light and porous skeleton consisting of interconnecting rods and spines. The colonies are either massive or branching and often have irregular shapes. The corallites have walls that are very perforated and septa that are mostly composed of fine spines which may meet in the centre forming a tangle of columella. The polyps are large and fleshy and are normally extended both day and night. They have twelve tentacles, often with swollen knob-like tips. They have symbiotic zooxanthellae Zooxanthellae is a colloquial term for single-celled dinoflagellates that are able to live in symbiosis with diverse marine invertebrates including demosponges, corals, jellyfish, and nudibranchs. Most known zooxanthellae are in the genus '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pliensbachian
The Pliensbachian is an age of the geologic timescale and stage in the stratigraphic column. It is part of the Early or Lower Jurassic Epoch or Series and spans the time between 190.8 ± 1.5 Ma and 182.7 ± 1.5 Ma (million years ago). The Pliensbachian is preceded by the Sinemurian and followed by the Toarcian. The Pliensbachian ended with the extinction event called the Toarcian turnover. During the Pliensbachian, the middle part of the Lias was deposited in Europe. The Pliensbachian is roughly coeval with the Charmouthian regional stage of North America. Stratigraphic definitions The Pliensbachian takes its name from the hamlet of Pliensbach in the community of Zell unter Aichelberg in the Swabian Alb, some 30 km east of Stuttgart in Germany. The name was introduced into scientific literature by German palaeontologist Albert Oppel in 1858. The base of the Pliensbachian is at the first appearances of the ammonite species '' Bifericeras donovani'' and genera ''Apoderocer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Jurassic
The Early Jurassic Epoch (geology), Epoch (in chronostratigraphy corresponding to the Lower Jurassic series (stratigraphy), Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic-Jurassic extinction event, 201.3 Ma (million years ago), and ends at the start of the Middle Jurassic 174.1 Ma. Certain rocks of marine origin of this age in Europe are called "Lias Group, Lias" and that name was used for the period, as well, in 19th-century geology. In southern Germany rocks of this age are called Black Jurassic. Origin of the name Lias There are two possible origins for the name Lias: the first reason is it was taken by a geologist from an England, English quarryman's dialect pronunciation of the word "layers"; secondly, sloops from north Cornwall, Cornish ports such as Bude would sail across the Bristol Channel to the Vale of Glamorgan to load up with rock from coastal limestone quarries (lias limestone from S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coral
Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton. A coral "group" is a colony of very many genetically identical polyps. Each polyp is a sac-like animal typically only a few millimeters in diameter and a few centimeters in height. A set of tentacles surround a central mouth opening. Each polyp excretes an exoskeleton near the base. Over many generations, the colony thus creates a skeleton characteristic of the species which can measure up to several meters in size. Individual colonies grow by asexual reproduction of polyps. Corals also breed sexually by spawning: polyps of the same species release gametes simultaneously overnight, often around a full moon. Fertilized eggs form planulae, a mobile early form of the coral polyp which, when m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aruma Formation
The Slow goby (''Aruma histrio'') is a species of goby fish endemic to the Gulf of California on the west coast of North America. It inhabits crevices in rocks and can be found in tide pools down to a depth of around . This species grows to a maximum length of SL. This species is the only known member of its genus. Description It is brown with 6-7 white bars along its side, with some bars weak or missing. There is a narrow white bar at the base of its pectoral fin, followed by a dark brown bar. It is elongated and somewhat compressed. Its large head is flattened with swollen cheeks and a large mouth. It has a pore between its eyes, and two small pores on its preopercle. Its tail fin is long and rounded without scales or a lateral line. Habitat The slow goby inhabits rocky crevices in tide pools and under cobble in shallow water. The larvae are usually found around sargassum. It needs a temperature of 20.8-23.8 degrees Celsius (69.4-74.8 degrees Fahrenheit). Adults are be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Campanian
The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campanian spans the time from 83.6 (± 0.2) to 72.1 (± 0.2) million years ago. It is preceded by the Santonian and it is followed by the Maastrichtian. The Campanian was an age when a worldwide sea level rise covered many coastal areas. The morphology of some of these areas has been preserved: it is an unconformity beneath a cover of marine sedimentary rocks. Etymology The Campanian was introduced in scientific literature by Henri Coquand in 1857. It is named after the French village of Champagne in the department of Charente-Maritime. The original type locality was a series of outcrop near the village of Aubeterre-sur-Dronne in the same region. Definition The base of the Campanian Stage is defined as a place in the stratigraphic column wher ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Australia and Ant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
