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Trachymetopon
''Trachymetopon'' is an extinct genus of prehistoric coelacanth from the Jurassic of Europe. Fossils have been found in the Early Jurassic Posidonia Shale of Germany the Middle Jurassic Marnes de Dives of France, and probably the Late Jurassic Kimmeridge Clay of England. Only one species has been named, ''Trachymetopon liassicum'', described by Henning in 1951 from an almost complete specimen found in the Lower Toarcian of Ohmden in Baden-Württemberg.Hennig, E. (1951). Trachymetopon liassicum, Ald., ein Reisen-Crossopterygier aus Schwäbischem Ober-Lias. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen, Stuttgart, 94, 67-79. Another specimen is known from the same site, and two older specimens come from the Sinemurian of Holzmaden. The holotype of this species is in length. A giant specimen of an undetermined species of ''Trachymetopon'' found at the Middle Jurassic (Late Callovian) Falaises des Vaches Noires of Normandy. This specimen, composed of a 53 cm long palat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mawsoniidae
Mawsoniidae is an extinct family of prehistoric coelacanth fishes which lived during the Triassic to Cretaceous periods. Members of the family are distinguished from their sister group, the Latimeriidae (which contains the living coelacanths of the genus ''Latimeria'') by the presence of ossified ribs, a coarse rugose texture on the dermatocranium and cheek bones, the absence of the suboperculum and the spiracular, and reduction or loss of the descending process of the supratemporal. Mawsoniids are known from North America, Europe, South America, Africa, Madagascar and Asia. Unlike Latimeriidae, which are exclusively marine, Mawsoniidae were also native to freshwater and brackish environments. Mawsoniids represent among the youngest known coelacanths, with the youngest known remains of the freshwater genus ''Axelrodichthys'' from France and an indeterminate marine species from Morocco being from the final stage of the Cretaceous, the Maastrichtian, roughly equivalent in age to th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Axelrodichthys
''Axelrodichthys'' is an extinct genus of mawsoniid coelacanth from the Cretaceous of Africa, North and South America, and Europe. Several species are known, the remains of which were discovered in the Lower Cretaceous (Aptian-Albian) of Brazil, North Africa, and possibly Mexico, as well as in the Upper Cretaceous of Morocco (Cenomanian), Madagascar (Coniacian –Santonian) and France (Lower Campanian to Lower Maastrichtian). The ''Axelrodichthys'' of the Lower Cretaceous frequented both brackish and coastal marine waters (lagoon-coastal environment) while the most recent species lived exclusively in fresh waters (lakes and rivers). The French specimens are the last known fresh water coelacanths. Most of the species of this genus reached to in length. ''Axelrodichthys'' was named in 1986 by John G. Maisey in honor of the American ichthyologist Herbert R. Axelrod. Description Like its close relative '' Mawsonia'', ''Axelrodichthys'' is a coelacanth with an elongated, low, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coelacanth
The coelacanths ( ) are fish belonging to the order Actinistia that includes two extant species in the genus ''Latimeria'': the West Indian Ocean coelacanth (''Latimeria chalumnae''), primarily found near the Comoro Islands off the east coast of Africa, and the Indonesian coelacanth (''Latimeria menadoensis''). The name "coelacanth" originates from the Permian genus ''Coelacanthus'', which was the first scientifically named coelacanth. Coelacanths follow the oldest-known living lineage of Sarcopterygii (lobe-finned fish and tetrapods), which means they are more closely related to lungfish and tetrapods (which includes amphibians, reptiles, birds and mammals) than to ray-finned fish. They are found along the coastline of Indonesia and in the Indian Ocean. The West Indian Ocean coelacanth is a critically endangered species. The oldest known coelacanth fossils are over 410 million years old. Coelacanths were thought to have become extinct in the Late Cretaceous, around 66 m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mawsonia (fish)
''Mawsonia'' is an extinct genus of prehistoric coelacanth fish. It is the amongst the largest of all coelacanths, with one quadrate specimen (DGM 1.048-P) possibly belonging to an individual measuring in length. It lived in freshwater and brackish environments from the latest Jurassic to the mid-Cretaceous ( Tithonian to Cenomanian stages, about 152 to 96 million years ago) of South America, eastern North America, and Africa. ''Mawsonia'' was first described by British paleontologist Arthur Smith Woodward in 1907.''Mawsonia'' at Fossilworks.org Description [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marnes De Dives
The Marnes de Dives is a geological formation in Normandy, France. It dates back to the upper part of the Callovian stage of the Middle Jurassic.Weishampel, David B; et al. (2004). "Dinosaur distribution (Middle Jurassic, Europe)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 538–541. . And is partially equivalent to the Oxford Clay in England. It predominantly consists of ooidal marl, rich in pyrite and lignite, interbedded with thin limestone horizons. It is best exposed at the base of the Falaises des Vaches Noires (Cliffs of Black Cows) as well as the foreshore at low tide. It is known for its fossils, notably those of ammonites, marine crocodiles and fragmentary remains of dinosaurs, mostly theropods. Vertebrate fauna See also * List of dinosaur-bearing rock formations This list of dinosaur-bearing rock formations is a list of geologic formations in which dinosaur fossils have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Largest Prehistoric Animals
The largest prehistoric animals include both vertebrate and invertebrate species. Many of them are described below, along with their typical range of size (for the general dates of extinction, see the link to each). Many species mentioned might not actually be the largest representative of their clade due to the incompleteness of the fossil record and many of the sizes given are merely estimates since no complete specimen have been found. Their body mass, especially, is largely conjecture because soft tissue was rarely fossilized. Generally the size of extinct species was subject to energetic and biomechanical constraints. Non-mammalian synapsids (Synapsida) Caseasaurs (Caseasauria) The herbivorous ''Alierasaurus'' was the largest caseid and the largest amniote to have lived at the time, with an estimated length around . '' Cotylorhynchus hancocki'' is also large, with an estimated length and weight of at least and more than . Edaphosaurids (Edaphosauridae) The larges ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinemurian
In the geologic timescale, the Sinemurian is an age and stage in the Early or Lower Jurassic Epoch or Series. It spans the time between 199.3 ± 2 Ma and 190.8 ± 1.5 Ma (million years ago). The Sinemurian is preceded by the Hettangian and is followed by the Pliensbachian. In Europe the Sinemurian age, together with the Hettangian age, saw the deposition of the lower Lias, in Great Britain known as the Blue Lias. Stratigraphic definitions The Sinemurian Stage was defined and introduced into scientific literature by French palaeontologist Alcide d'Orbigny in 1842. It takes its name from the French town of Semur-en-Auxois, near Dijon. The calcareous soil formed from the Jurassic limestone of the region is in part responsible for the character of the classic Sancerre wines. The base of the Sinemurian Stage is at the first appearance of the ammonite genera ''Vermiceras'' and '' Metophioceras'' in the stratigraphic record. A global reference profile ( GSSP or golden spike) for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Normandy
Normandy (; french: link=no, Normandie ; nrf, Normaundie, Nouormandie ; from Old French , plural of ''Normant'', originally from the word for "northman" in several Scandinavian languages) is a geographical and cultural region in Northwestern Europe, roughly coextensive with the historical Duchy of Normandy. Normandy comprises mainland Normandy (a part of France) and the Channel Islands (mostly the British Crown Dependencies). It covers . Its population is 3,499,280. The inhabitants of Normandy are known as Normans, and the region is the historic homeland of the Norman language. Large settlements include Rouen, Caen, Le Havre and Cherbourg. The cultural region of Normandy is roughly similar to the historical Duchy of Normandy, which includes small areas now part of the departments of Mayenne and Sarthe. The Channel Islands (French: ''Îles Anglo-Normandes'') are also historically part of Normandy; they cover and comprise two bailiwicks: Guernsey and Jersey, which are B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphenoid Bone
The sphenoid bone is an unpaired bone of the neurocranium. It is situated in the middle of the skull towards the front, in front of the basilar part of occipital bone, basilar part of the occipital bone. The sphenoid bone is one of the seven bones that articulate to form the orbit (anatomy), orbit. Its shape somewhat resembles that of a butterfly or bat with its wings extended. Structure It is divided into the following parts: * a median portion, known as the body of sphenoid bone, containing the sella turcica, which houses the pituitary gland as well as the paired paranasal sinuses, the sphenoidal sinuses * two Greater wing of sphenoid bone, greater wings on the lateral side of the body and two Lesser wing of sphenoid bone, lesser wings from the anterior side. * Pterygoid processes of the sphenoides, directed downwards from the junction of the body and the greater wings. Two sphenoidal conchae are situated at the anterior and inferior part of the body. Intrinsic ligaments of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brackish Water
Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root '' brak''. Certain human activities can produce brackish water, in particular civil engineering projects such as dikes and the flooding of coastal marshland to produce brackish water pools for freshwater prawn farming. Brackish water is also the primary waste product of the salinity gradient power process. Because brackish water is hostile to the growth of most terrestrial plant species, without appropriate management it is damaging to the environment (see article on shrimp farms). Technically, brackish water contains between 0.5 and 30 grams of salt per litre—more often expressed as 0.5 to 30 parts per thousand (‰), which is a specific gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triassic
The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period of the Mesozoic Era. Both the start and end of the period are marked by major extinction events. The Triassic Period is subdivided into three epochs: Early Triassic, Middle Triassic and Late Triassic. The Triassic began in the wake of the Permian–Triassic extinction event, which left the Earth's biosphere impoverished; it was well into the middle of the Triassic before life recovered its former diversity. Three categories of organisms can be distinguished in the Triassic record: survivors from the extinction event, new groups that flourished briefly, and other new groups that went on to dominate the Mesozoic Era. Reptiles, especially archosaurs, were the chief terrestrial vertebrates during this time. A specialized subgroup of archo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fresh Water
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include non- salty mineral-rich waters such as chalybeate springs. Fresh water may encompass frozen and meltwater in ice sheets, ice caps, glaciers, snowfields and icebergs, natural precipitations such as rainfall, snowfall, hail/ sleet and graupel, and surface runoffs that form inland bodies of water such as wetlands, ponds, lakes, rivers, streams, as well as groundwater contained in aquifers, subterranean rivers and lakes. Fresh water is the water resource that is of the most and immediate use to humans. Water is critical to the survival of all living organisms. Many organisms can thrive on salt water, but the great majority of higher plants and most insects, amphibians, reptiles, mammals and birds need fresh water to survive. Fresh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
