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Leptolepis Coryphaenoides
''Leptolepis'' (from el, λεπτός , 'slight' and el, λεπίς 'scale') is an extinct genus of stem-teleost fish that lived in what is now Europe during the Jurassic period (Toarcian–Callovian ages). Species The genus ''Leptolepis'' was for a long time used as a wastebasket taxon for various small, unspecialised teleosts that did not form a natural clade. In 1974 the Swedish ichthyologist Orvar Nybelin revised the genus, restricting it to seven species from the Early to Middle Jurassic of Europe. Other species were reassigned to different genera. * ''Leptolepis autissiodorensis'' * ''Leptolepis coryphaenoides'' * ''Leptolepis jaegeri'' * ''Leptolepis nathorsti'' * ''Leptolepis normandica'' * ''Leptolepis saltviciensis'' * ''Leptolepis woodwardi'' Species formerly placed in ''Leptolepis'' * ''Leptolepis talbragarensis'' (Now referred to '' Cavenderichthys'') * ''Leptolepis koonwarri'' (Now referred to '' Waldmanichthys'')Sferco, Emilia, Adriana López-Arb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Louis Agassiz
Jean Louis Rodolphe Agassiz ( ; ) FRS (For) FRSE (May 28, 1807 – December 14, 1873) was a Swiss-born American biologist and geologist who is recognized as a scholar of Earth's natural history. Spending his early life in Switzerland, he received a PhD at Erlangen and a medical degree in Munich. After studying with Georges Cuvier and Alexander von Humboldt in Paris, Agassiz was appointed professor of natural history at the University of Neuchâtel. He emigrated to the United States in 1847 after visiting Harvard University. He went on to become professor of zoology and geology at Harvard, to head its Lawrence Scientific School, and to found its Museum of Comparative Zoology. Agassiz is known for observational data gathering and analysis. He made institutional and scientific contributions to zoology, geology, and related areas, including multivolume research books running to thousands of pages. He is particularly known for his contributions to ichthyological classific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cartilage
Cartilage is a resilient and smooth type of connective tissue. In tetrapods, it covers and protects the ends of long bones at the joints as articular cartilage, and is a structural component of many body parts including the rib cage, the neck and the bronchial tubes, and the intervertebral discs. In other taxa, such as chondrichthyans, but also in cyclostomes, it may constitute a much greater proportion of the skeleton. It is not as hard and rigid as bone, but it is much stiffer and much less flexible than muscle. The matrix of cartilage is made up of glycosaminoglycans, proteoglycans, collagen fibers and, sometimes, elastin. Because of its rigidity, cartilage often serves the purpose of holding tubes open in the body. Examples include the rings of the trachea, such as the cricoid cartilage and carina. Cartilage is composed of specialized cells called chondrocytes that produce a large amount of collagenous extracellular matrix, abundant ground substance that is rich in p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bathonian Genera
In the geologic timescale the Bathonian is an age and stage of the Middle Jurassic. It lasted from approximately 168.3 Ma to around 166.1 Ma (million years ago). The Bathonian Age succeeds the Bajocian Age and precedes the Callovian Age. Stratigraphic definitions The Bathonian Stage takes its name from Bath, a spa town in England built on Jurassic limestone (the Latinized form of the town name is ''Bathonium''). The name was introduced in scientific literature by Belgian geologist d'Omalius d'Halloy in 1843. The original type locality was located near Bath. The French palaeontologist Alcide d'Orbigny was in 1852 the first to define the exact length of the stage. The base of the Bathonian is at the first appearance of ammonite species '' Parkinsonia (Gonolkites) convergens'' in the stratigraphic column. The global reference profile for the base of the Bathonian (a GSSP) was ratified as Ravin du Bès, Bas-Auran area, Alpes de Haute Provence, France in 2009. The top of the Bathon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toarcian Genus First Appearances
The Toarcian is, in the ICS' geologic timescale, an age and stage in the Early or Lower Jurassic. It spans the time between 182.7 Ma (million years ago) and 174.1 Ma. It follows the Pliensbachian and is followed by the Aalenian. The Toarcian Age began with the Toarcian turnover, the extinction event that sets its fossil faunas apart from the previous Pliensbachian age. It is believed to have ended with a global cooling event known as the Comptum Cooling Event, although whether it represented a worldwide event is controversial. Stratigraphic definitions The Toarcian takes its name from the city of Thouars, just south of Saumur in the Loire Valley of France. The stage was introduced by French palaeontologist Alcide d'Orbigny in 1842, after examining rock strata of this age in a quarry near Thouars. In Europe this period is represented by the upper part of the Lias. The base of the Toarcian is defined as the place in the stratigraphic record where the ammonite genus '' Eodact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Ray-finned Fish Genera
Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared 5000 years ago. It took thousands of years for writing systems to be widely adopted, with writing spreading to almost all cultures by the 19th century. The end of prehistory therefore came at very different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilisation, and ancient Egypt were the first civilizations to develop their own scripts and to keep historical records, with their neighbors following. Most other civilizations reached the end of prehistory during the following Iron Age. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Teleostei
Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared 5000 years ago. It took thousands of years for writing systems to be widely adopted, with writing spreading to almost all cultures by the 19th century. The end of prehistory therefore came at very different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilisation, and ancient Egypt were the first civilizations to develop their own scripts and to keep historical records, with their neighbors following. Most other civilizations reached the end of prehistory during the following Iro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hulettia
''Hulettia'' is an extinct genus of ray-finned fish found in the Morrison Formation in the western United States, measuring approximately three to four inches in length. This fish genus contains one species, ''H. americana''. Its body was covered in thick prominent scales, and its name is based on Hulett, Wyoming, a locale which is near the Morrison Formation. Discovered specimens show evidence of predation upon the smaller species of fish ''Todiltia'' that inhabited the Jurassic Lake Todilto, and another specimen discovered in the Bathonian coastal sandstone, in the Sundance Formation of South Dakota. Both specimens are complete skeletons with no fragmentary remains or dubious anomalies amongst the bones recovered. Description ''Hulettia'' reached their maximum size of . It is believed that the colossal deposits of uranium that are found in Todilto Formation and the Morrison Formation deterred other organisms from the area, and isolated the two species, protecting them from pre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morrolepis
''Morrolepis'' is an extinct genus of prehistoric coccolepidid " palaeoniscoid" ray-finned fish that lived during the Late Jurassic and earliest Cretaceous epochs in Europe, Asia and North America. The type species is ''Morrolepis schaefferi'' from the Morrison Formation (Colorado, Utah), measuring approximately in length. The other species were previously referred to the genus '' Coccolepis''. Including ''M. andrewsi'' (Woodward, 1891) from the earliest Cretaceous (Berriasian) Purbeck Group, England and ''M. aniscowitchi'' (Gorizdor-Kulczycka, 1926) from the late Middle Jurassic-early Late Jurassic (Callovian/ Oxfordian) Karabastau Formation of Kazakhstan. See also * Prehistoric fish * List of prehistoric bony fish * Paleobiota of the Morrison Formation The Morrison Formation is a distinctive sequence of Late Jurassic sedimentary rock that is found in the western United States, which has a wide assortment of taxa represented in its fossil record, including dinosaur foss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clarkeiteuthis
''Clarkeiteuthis'' is a genus of extinct belemnoid cephalopod known from the lower Jurassic in Germany and England. Described two species, ''C. conocauda'' and ''C. montefiorei'' are originally described as species of phragmoteuthid ''Phragmoteuthis'', but got their own genus and moved to Diplobelida. Description Two species are described, ''C. conocauda'' is known from Posidonia Shale, and ''C. montefiorei'' is known from Charmouth Mudstone Formation. ''Clarkeiteuthis'' had long phragmocone and ten short, hook-bearing arms. Although it is originally considered as phragmoteuthid, this classification has been discussed by modern researchers, as it lacked a broad three-lobed proostracum (The anterior prolongation of the guard of the phragmocone), the autapomorphy of phragmoteuthid. ''C. conocauda'' had total length about . This species is well preserved, soft tissues such as mantle and ink sac are visible. One arm had around 30 hooks. Palaeobiology Well-preserved spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pelagosaurus
''Pelagosaurus'' (meaning "lizard of the open sea") is an extinct genus of thalattosuchian crocodyliform that lived during the Toarcian stage of the Lower Jurassic, around 183 Ma to 176 Ma (million years ago), in shallow epicontinental seas that covered much of what is now Western Europe. The systematic taxonomy of ''Pelagosaurus'' has been fiercely disputed over the years, and was assigned to Thalattosuchia after its systematics within Teleosauridae were disputed. ''Pelagosaurus'' measured long and weighed . Discovery ''Pelagosaurus'' was originally described from a specimen from Normandy, but the holotype for ''P. typus'' was discovered north of the town of Ilminster in Somerset, England. Most ''Pelagosaurus'' remains have been found in the Ilminster area, but numerous other remains, predominantly skulls and articulated skeletons, have been found around Western Europe in locations such as France, Germany, and Switzerland. Specimens from the Somerset region come primarily ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plankton
Plankton are the diverse collection of organisms found in water (or air) that are unable to propel themselves against a current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucial source of food to many small and large aquatic organisms, such as bivalves, fish and whales. Marine plankton include bacteria, archaea, algae, protozoa and drifting or floating animals that inhabit the saltwater of oceans and the brackish waters of estuaries. Freshwater plankton are similar to marine plankton, but are found in the freshwaters of lakes and rivers. Plankton are usually thought of as inhabiting water, but there are also airborne versions, the aeroplankton, that live part of their lives drifting in the atmosphere. These include plant spores, pollen and wind-scattered seeds, as well as microorganisms swept into the air from terrestrial dust storms and oceanic plankton swept into the air by sea spray. Though m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shoaling And Schooling
In biology, any group of fish that stay together for social reasons are shoaling, and if the group is swimming in the same direction in a coordinated manner, they are schooling. In common usage, the terms are sometimes used rather loosely. About one quarter of fish species shoal all their lives, and about one half shoal for part of their lives. Fish derive many benefits from shoaling behaviour including defence against predators (through better predator detection and by diluting the chance of individual capture), enhanced foraging success, and higher success in finding a mate. It is also likely that fish benefit from shoal membership through increased hydrodynamic efficiency. Fish use many traits to choose shoalmates. Generally they prefer larger shoals, shoalmates of their own species, shoalmates similar in size and appearance to themselves, healthy fish, and kin (when recognized). The oddity effect posits that any shoal member that stands out in appearance will be prefe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
