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Halosaur
Halosaurs are eel-shaped fishes found only at great ocean depths. As the family Halosauridae, halosaurs are one of two families within the order Notacanthiformes; the other being the deep-sea spiny eels, Notacanthidae. Halosaurs are thought to have a worldwide distribution, with some 17 species in three genera represented. Only a handful of specimens have been observed alive, all in chance encounters with Remotely operated underwater vehicles. The term "halosaur" refers to the type genus, '' Halosaurus'', which is a Greek compound word, ''hals'' meaning "sea" and ''sauros'' meaning "lizard". Halosaurs have a spotty fossil record, the oldest known genus being '' Echidnocephalus'' from the Late Cretaceous (Campanian) strata of Westphalia, Germany, and the second-oldest known genus, '' Laytonia'', from Miocene strata of California and Oregon. The fossil specimens already bear strong resemblance to the modern genera. The halosaurs' greatly elongated bodies end in whip-like tails; ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halosaurus
''Halosaurus'' is a genus of fish in the family Halosauridae. This genus currently contains the following recognized species: * '' Halosaurus attenuatus'' Garman, 1899 (Galapagos halosaur) * '' Halosaurus carinicauda'' (Alcock, 1889) (Andaman halosaur) * '' Halosaurus guentheri'' Goode & T. H. Bean, 1896 (Guenther's halosaur) * ''Halosaurus johnsonianus'' Vaillant, 1888 (Sahara halosaur) * †''Halosaurus orthensis'' Nolf 2002 * ''Halosaurus ovenii'' J. Y. Johnson, 1864 (Madeira halosaur) * ''Halosaurus pectoralis'' McCulloch, 1926 (Goanna fish) * ''Halosaurus radiatus'' Garman, 1899 (Albatross halosaur) * ''Halosaurus ridgwayi'' ( Fowler, 1934) (Ridgeway's halosaur) * ''Halosaurus sinensis ''Halosaurus'' is a genus of fish in the family Halosauridae. This genus currently contains the following recognized species: * '' Halosaurus attenuatus'' Garman, 1899 (Galapagos halosaur) * '' Halosaurus carinicauda'' (Alcock, 1889) (Andama ...'' T. Abe, 1974 (Chinese halosaur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abyssal Halosaur
The abyssal halosaur (''Halosauropsis macrochir'') is a species of bottom-dwelling, deep-sea fish in the family Halosauridae that is found in all oceans at depths of 1100 to 3500 meters. It is the only member of its genus. Abyssal halosaur can reach total length of at least and weight in excess of . Berstad et al. could not sex fish smaller than 25 cm, giving an indication about length at maturation. Abyssal halosaur are long-lived, with maximum reported age of 36 years, although individuals sampled on the Mid-Atlantic Ridge The Mid-Atlantic Ridge is a mid-ocean ridge (a Divergent boundary, divergent or constructive Plate tectonics, plate boundary) located along the floor of the Atlantic Ocean, and part of the List of longest mountain chains on Earth, longest mountai ... were mostly <20 years. It appears to be an opportunistic feeder, mostly taking epibenthos and small fish. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echidnocephalus
''Echidnocephalus'' (Greek for " Echidna's head") is an extinct genus of prehistoric halosaur known from the Late Cretaceous. It is the earliest known definitive member of the order Notacanthiformes. It contains one definitive species known from complete and partial specimens: ''E. troscheli'' (=''E. tenuicaudus'' von der Marck, 1858) from the late Campanian-aged Ahlen Formation of Westphalia, Germany. These body fossils suggest an animal already very similar to modern halosaurs. In addition, two disputed species known only from isolated fossil scales very similar to those of modern halosaurs have been described from North America: ?''E. americanus'' Cockerell, 1919 from the Coniacian-aged Mancos Shale of Wyoming and ?''E. pacificus'' Cockerell, 1919 from the Maastrichtian-aged Moreno Formation of California. See also * '' Laytonia'', a Miocene genus of fossil halosaur * Prehistoric fish * List of prehistoric bony fish This list of prehistoric bony fish is an attempt t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laytonia
''Laytonia'' is an extinct genus of prehistoric halosaur that lived in deep water off the North American Pacific Coast from the Zemorrian Epoch (comprising either the latest Oligocene or lower Miocene) until during the Upper Miocene subepoch, when tectonic uplift effectively destroyed the genus' habitat by making the deep water too shallow.David, Lore Rose. January 10, 1943. Miocene Fishes of Southern California The Society There are two species recognized, the type species, ''L. californica'', which is known from at least 2 whole fossils, and fossil scales from Upper Miocene strata of Southern California, and ''L. zemorrensis'', known from fossil scales in Zemorrian strata (either Oligocene or Lower Miocene) from Oregon and California. According to the fossils of ''L. californica'', the living animals were very slender, and had a long, fringe-like dorsal fin running almost the entire length of the body, from the head to the tip of the tail. The dorsal fin forms two crests, a fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the more recent 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, Aus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reptile
Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocephalia. About 12,000 living species of reptiles are listed in the Reptile Database. The study of the traditional reptile orders, customarily in combination with the study of modern amphibians, is called herpetology. Reptiles have been subject to several conflicting Taxonomy, taxonomic definitions. In Linnaean taxonomy, reptiles are gathered together under the Class (biology), class Reptilia ( ), which corresponds to common usage. Modern Cladistics, cladistic taxonomy regards that group as Paraphyly, paraphyletic, since Genetics, genetic and Paleontology, paleontological evidence has determined that birds (class Aves), as members of Dinosauria, are more closely related to living crocodilians than to other reptiles, and are thus nested among re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Remotely Operated Underwater Vehicle
A remotely operated underwater vehicle (ROUV) or remotely operated vehicle (ROV) is a free-swimming submersible craft used to perform underwater observation, inspection and physical tasks such as valve operations, hydraulic functions and other general tasks within the subsea oil and gas industry, military, scientific and other applications. ROVs can also carry tooling packages for undertaking specific tasks such as pull-in and connection of flexible flowlines and umbilicals, and component replacement. They are often used to do research and commercial work at great depths beyond the capacities of most submersibles and divers. Description This meaning is different from remote control vehicles operating on land or in the air because ROVs are designed specifically to function in underwater environments, where conditions such as high pressure, limited visibility, and the effects of buoyancy and water currents pose unique challenges. While land and aerial vehicles use wireless commu ... [...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 outcrops 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benthic
The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from the Ancient Greek word (), meaning "the depths". Organisms living in this zone are called benthos and include microorganisms (e.g., bacteria and fungi) as well as larger invertebrates, such as crustaceans and polychaetes. Organisms here, known as bottom dwellers, generally live in close relationship with the substrate and many are permanently attached to the bottom. The benthic boundary layer, which includes the bottom layer of water and the uppermost layer of sediment directly influenced by the overlying water, is an integral part of the benthic zone, as it greatly influences the biological activity that takes place there. Examples of contact soil layers include sand bottoms, rocky outcrops, coral, and bay mud. Description Oceans The benthic region of the ocean begins at the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Snake
Sea snakes, or coral reef snakes, are Elapidae, elapid snakes that inhabit Marine (ocean), marine environments for most or all of their lives. They belong to two subfamilies, Hydrophiinae and Sea krait, Laticaudinae. Hydrophiinae also includes Australasian terrestrial snakes, whereas Laticaudinae only includes the sea kraits (''Laticauda''), of which three species are found exclusively in freshwater. If these three freshwater species are excluded, there are 69 species of sea snakes divided among seven Genus, genera. Most sea snakes are venomous snake, venomous, except the genus ''Emydocephalus'', which feeds almost exclusively on fish eggs. Sea snakes are extensively adapted to a fully aquatic life and are unable to move on land, except for the sea kraits, which have limited land movement. They are found in warm coastal waters from the Indian Ocean to the Pacific and are closely related to venomous terrestrial snakes in Australia. All sea snakes have paddle-like tails and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Invertebrate
Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate subphylum Vertebrata, i.e. vertebrates. Well-known Phylum, phyla of invertebrates include arthropods, molluscs, annelids, echinoderms, flatworms, cnidarians, and sponges. The majority of animal species are invertebrates; one estimate puts the figure at 97%. Many invertebrate taxon, taxa have a greater number and diversity of species than the entire subphylum of Vertebrata. Invertebrates vary widely in size, from 10 Micrometre, μm (0.0004 in) myxozoans to the 9–10 m (30–33 ft) colossal squid. Some so-called invertebrates, such as the Tunicata and Cephalochordata, are actually sister chordate subphyla to Vertebrata, being more closely related to vertebrates than to other invertebrates. This makes the "invertebrates" para ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echinoderm
An echinoderm () is any animal of the phylum Echinodermata (), which includes starfish, brittle stars, sea urchins, sand dollars and sea cucumbers, as well as the sessile sea lilies or "stone lilies". While bilaterally symmetrical as larvae, as adults echinoderms are recognisable by their usually five-pointed radial symmetry (pentamerous symmetry), and are found on the sea bed at every ocean depth from the intertidal zone to the abyssal zone. The phylum contains about 7,600 living species, making it the second-largest group of deuterostomes after the chordates, as well as the largest marine-only phylum. The first definitive echinoderms appeared near the start of the Cambrian. Echinoderms are important both ecologically and geologically. Ecologically, there are few other groupings so abundant in the deep sea, as well as shallower oceans. Most echinoderms are able to reproduce asexually and regenerate tissue, organs and limbs; in some cases, they can undergo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
