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Hovasaurus
''Hovasaurus'' is an extinct genus of diapsid reptile belonging to the order Eosuchia. It lived in what is now Madagascar during the Late Permian and Early Triassic, being a survivor of the Permian–Triassic extinction event and the paleontologically youngest member of the Tangasauridae. Fossils have been found in the Permian Lower and Triassic Middle Sakamena Formations of the Sakamena Group, where it is amongst the commonest fossils. Its morphology suggests an aquatic ecology. Description ''Hovasaurus'' resembled a slender lizard, two thirds of total length was taken up by its long tail. It had snout-vent length up to long, with long tail. It was well adapted to an aquatic life, with the tail being laterally flattened like that of a sea snake. Some stones have been found in the abdomen of fossil ''Hovasaurus'', indicating the creatures swallowed these for ballast, preventing them from floating to the surface when hunting fish. Paleoenvironment The Lower Sakamamena F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hovasaurus
''Hovasaurus'' is an extinct genus of diapsid reptile belonging to the order Eosuchia. It lived in what is now Madagascar during the Late Permian and Early Triassic, being a survivor of the Permian–Triassic extinction event and the paleontologically youngest member of the Tangasauridae. Fossils have been found in the Permian Lower and Triassic Middle Sakamena Formations of the Sakamena Group, where it is amongst the commonest fossils. Its morphology suggests an aquatic ecology. Description ''Hovasaurus'' resembled a slender lizard, two thirds of total length was taken up by its long tail. It had snout-vent length up to long, with long tail. It was well adapted to an aquatic life, with the tail being laterally flattened like that of a sea snake. Some stones have been found in the abdomen of fossil ''Hovasaurus'', indicating the creatures swallowed these for ballast, preventing them from floating to the surface when hunting fish. Paleoenvironment The Lower Sakamamena F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tangasauridae
Tangasauridae is a family of diapsids. Specimens have been found that are of Late Permian to Early Triassic in age from the Sakamena Group of western Madagascar. They lived alongside other taxa present from the Sakamena Group, including temnospondyls, rhynchosaurs, and gomphodont eucynodonts. Fossils have been found of numerous specimens of common members of this family such as ''Hovasaurus'' and ''Thadeosaurus'' in different stages of ontogenic development.Currie, Philip J and Carroll, Robert L. (1984) Ontogenic changes in the eosuchian reptile ''Thadeosaurus''. ''Journal of Vertebrate Paleontology'' 4(1):68-84 Recent material from the Middle Sakamena Formation of the Morondava Basin of Madagascar that dates back to the early Triassic period suggests that the Tangasauridae were relatively unaffected by the Permian-Triassic extinction event. Description and phylogeny Tangasaurids are known to have been a highly derived group of diapsids. One subfamily, Kenyasaurinae, is com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eosuchia
Eosuchians are an extinct order of diapsid reptiles. Depending on which taxa are included the order may have ranged from the late Carboniferous to the Eocene but the consensus is that eosuchians are confined to the Permian and Triassic. Eosuchia was initially defined to include all "thecodontian" reptiles which did not have an antorbital fenestra but did retain tabulars, postparietals and a large pineal foramen (Broom, 1914). Broom coined the term as a new suborder for ''Youngina''. A definition for inclusion in the order is difficult: it is almost easier to list the primitively-diapsid reptiles that have not been included at one time or another. The order has almost been treated as a dustbin for diapsids that are not obviously lepidosaurian or archosaurian. One consequence has been Romer's suggestion of the alternative order Younginiformes to be applied strictly to those forms with the primitive diapsid form, in particular, a complete lowermost arch as the quadratojugal and j ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coelurosauravus
''Coelurosauravus'' (meaning "hollow lizard grandfather") is a genus of basal diapsid reptiles, known from the Late Permian of Madagascar. Like other members of the family Weigeltisauridae, members of this genus possessed long, rod-like ossifications projecting outwards from the body. These bony rods were not extensions of the ribs but were instead newly developed bones derived from the skin of the animal, a feature unique to weigeltisaurids. It is believed that during life, these structures formed folding wings used for gliding flight, similar to living gliding ''Draco'' lizards. ''Coelurosauravus'' is solely known from the type species, ''C. elivensis'', which was named by Jean Piveteau in 1926 based on fossils from the Lower Sakamena Formation of Madagascar. The species ''Weigeltisaurus jaekeli'' from Europe was formerly considered a species of ''Coelurosauravus'', but is now considered distinct. History of discovery The only known specimens of ''Coelurosauravus'' were coll ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reptile
Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates (lizards and snakes) and rhynchocephalians (tuatara). As of March 2022, the Reptile Database includes about 11,700 species. In the traditional Linnaean classification system, birds are considered a separate class to reptiles. However, crocodilians are more closely related to birds than they are to other living reptiles, and so modern cladistic classification systems include birds within Reptilia, redefining the term as a clade. Other cladistic definitions abandon the term reptile altogether in favor of the clade Sauropsida, which refers to all amniotes more closely related to modern reptiles than to mammals. The study of the traditional reptile orders, historically combined with that of modern amphibians, is called herpetology. The earliest known proto-reptiles originated around ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glossopteris
''Glossopteris'' tymology: from Ancient Greek γλῶσσα (glôssa, " tongue ") + πτερίς (pterís, " fern ")is the largest and best-known genus of the extinct Permian order of seed ferns known as Glossopteridales (also known as Arberiales, Ottokariales, or Dictyopteridiales). The genus ''Glossopteris'' refers only to leaves, within a framework of form genera used in paleobotany. (For likely reproductive organs see Glossopteridaceae.) Species of ''Glossopteris'' were the dominant trees of the middle- to high-latitude lowland vegetation across the supercontinent Gondwana during the Permian Period. ''Glossopteris'' fossils were critical in recognizing former connections between the various fragments of Gondwana: South America, Africa, India, Australia, New Zealand, and Antarctica. History The Glossopteridales arose in the Southern Hemisphere around the beginning of the Permian Period (), but became extinct during the end-Permian (Changhsingian) mass extinction. The putat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Tanganyika
Lake Tanganyika () is an African Great Lake. It is the second-oldest freshwater lake in the world, the second-largest by volume, and the second-deepest, in all cases after Lake Baikal in Siberia. It is the world's longest freshwater lake. The lake is shared among four countries—Tanzania, the Democratic Republic of the Congo (DRC), Burundi, and Zambia, with Tanzania (46%) and DRC (40%) possessing the majority of the lake. It drains into the Congo River system and ultimately into the Atlantic Ocean. Etymology "Tanganika" was the name of the lake that Henry Morton Stanley encountered when he was at Ujiji in 1876. The name first originated from the Bembe language when they arrived in South Kivu around the 7th century, they discovered the lake and started calling it “êtanga ‘ya’ni’â” which means “a big river” in their Bantu language. Stanley found also other names for the lake among different ethnic groups, like the Kimana, the Yemba and the Msaga. An alt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equisetales
Equisetales is an order of subclass Equisetidae with only one living family, Equisetaceae, containing the genus ''Equisetum'' (horsetails). Classification In the molecular phylogenetic classification of Smith et al. in 2006, Equisetales, in its present circumscription, was held to be the sole member of class Equisetopsida. The linear sequence of Christenhusz et al. (2011), intended for compatibility with the classification of Chase and Reveal (2009) which placed all land plants in Equisetopsida, made it the sole member of subclass Equisetidae, equivalent to Smith's Equisetopsida. The placement of Equisetales in subclass Equisetidae has subsequently been followed in the classifications of Christenhusz and Chase (2014) and PPG I (2016). The fossil record includes additional extinct species in Equisetaceae and the extinct families Calamitaceae, Archaeocalamitaceae and Phyllothecaceae The prehistoric family Phyllothecaceae, of the plant order Equisetales, was erected in 1828, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palaeoniscoid
Palaeoniscidae is an extinct family of ray-finned fishes (Actinopterygii) ascribed to the order Palaeonisciformes. The family includes the genus '' Palaeoniscum'' and potentially other Palaeozoic and Mesozoic early actinopterygian genera. The name is derived from the Ancient Greek words παλαιός (''palaiós'', ancient) and ὀνίσκος (''oniskos'', 'cod-fish' or woodlouse). Historic background The family was first named "Palaeoniscini" by Charles Lucien Bonaparte in 1846, and "Palaeonisciden" by Carl Vogt in 1851. Later, the family name was standardized to Palaeoniscidae. The authorship of the family Palaeoniscidae is variably attributed to either Bonaparte or Vogt in the literature. Vogt ascribed the following genera to Palaeoniscidae: ''Palaeoniscum'', ''Platysomus'' (misspelled as ''Platysemius''), ''Amblypterus'', '' Eurynotus'', '' Pygopterus'', and ''Acrolepis''. With the exception of ''Palaeoniscum'', these genera were later placed in separate families ( Platys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lepidopteris
''Lepidopteris'' ("scaly fern") is a form genus for leaves of Late Permian to Late Triassic Period Pteridospermatophyta, or seed ferns, which lived from around 260 to 200 million years ago in what is now Australia, Antarctica, India, South America, South Africa, Russia and China. Nine species are currently recognized. ''Lepidopteris'' was a common and widespread seed fern, which survived the Permian-Triassic extinction event but succumbed to the Triassic-Jurassic extinction event. ''Lepidopteris callipteroides'' is especially common between the first two episodes of Permian-Triassic extinction event, and ''L. ottonis'' forms a comparable acme zone immediate before the Triassic-Jurassic extinction event. ''Lepidopteris'' would persist into the Early Jurassic in Patagonia, represented by the species ''Lepidopteris scassoi.'' Description In the form generic system of paleobotany ''Lepidopteris'' is used only for leaves, which are fern-like with pinnules attached to the rac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sailing Ballast
Ballast is used in ships to provide moment to resist the lateral forces on the hull. Insufficiently ballasted boats tend to tip or heel excessively in high winds. Too much heel may result in the vessel capsizing. If a sailing vessel needs to voyage without cargo, then ballast of little or no value will be loaded to keep the vessel upright. Some or all of this ballast will then be discarded when cargo is loaded. Uses Ballast takes many forms. The simplest form of ballast used in small day sailers is so-called "live ballast", or the weight of the crew. By sitting on the windward side of the hull, the heeling moment must lift the weight of the crew. On more advanced racing boats, a wire harness called a trapeze is used to allow the crew to hang completely over the side of the hull without falling out; this provides much larger amounts of righting moment due to the larger leverage of the crew's weight, but can be dangerous if the wind suddenly dies, as the sudden loss of heeling ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
