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Palaeoxyris
''Palaeoxyris'' is a morphogenus of eggs cases, widely thought to have been produced by hybodonts, with a predominant occurrence in ancient freshwater environments. They comprise a beak, a body and a pedicle. They display a conspicuous right-handed spiral of collarettes around the body, and in some cases, the pedicle, resulting in a rhomboidal pattern when flattened during fossilisation. At the end of the beak was a tendril which attached the egg to vegetation during development. The body of the egg ranges in length from , depending on the species. Originally described as plant remains (being named after the plant genus ''Xyris ''Xyris'' is a genus of flowering plants, the yelloweyed grasses, in the yellow-eyed-grass family. The genus counts over 250 species, widespread over much of the world, with the center of distribution in the Guianas. The leaves are mostly dis ...''), it took decades before their true nature as animal eggs was revealed. Nearly 30 different ''Palaeox ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alexandre Brongniart
Alexandre Brongniart (5 February 17707 October 1847) was a French chemist, mineralogist, geologist, paleontologist, and zoologist, who collaborated with Georges Cuvier on a study of the geology of the region around Paris. Observing fossil content as well as lithology in sequences, he classified Tertiary formations and was responsible for defining 19th century geological studies as a subject of science by assembling observations and classifications. Brongniart was also the founder of the Musée national de Céramique-Sèvres (National Museum of Ceramics), having been director of the Sèvres Porcelain Factory from 1800 to 1847. Life He was born in Paris, the son of the architect Alexandre-Théodore Brongniart and father of the botanist Adolphe-Théodore Brongniart. In 1797, he became an instructor of natural history at the Central School of the Four Nations, and became the professor of mineralogy in 1822 at the Museum of Natural History in Paris. He was appointed in 1800 by N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lonchidion
''Lonchidion'' is a genus of extinct Hybodontiform shark in the family Lonchidiidae. The genus first appears in the fossil record during the late Triassic and continues to be found until the late cretaceous. Lonchidion was first described by R. Estes in 1964, and the type species is ''L. selachas''. Fossils of ''Lonchidion'' have been discovered across North America, Eurasia, India and northwest Africa in sediments representative of a variety of environments. A new species, ''L. ferganensis'', was described by Jan Fischer, Sebastian Voigt, Jörg W. Schneider, Michael Buchwitz and Silke Voigt in 2011, from fossilized teeth and egg capsules. Species * ''Lonchidion anitae'' Thurmond, 1971 * ''Lonchidion breve'' Patterson, 1966 * ''Lonchidion crenulatum'' Patterson, 1966 * ''Lonchidion humblei'' Murry, 1981 [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic Sharks
The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of the Mesozoic Era and is named after the Jura Mountains, where limestone strata from the period were first identified. The start of the Jurassic was marked by the major Triassic–Jurassic extinction event, associated with the eruption of the Central Atlantic Magmatic Province. The beginning of the Toarcian Stage started around 183 million years ago and is marked by an extinction event associated with widespread oceanic anoxia, ocean acidification, and elevated temperatures likely caused by the eruption of the Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear boundary with the Cretaceous and is the only boundary between geological periods to remain formally undefined. By the beginning of the Jurassic, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triassic Sharks
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 archosaurs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permian Sharks
The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleozoic Era; the following Triassic Period belongs to the Mesozoic Era. The concept of the Permian was introduced in 1841 by geologist Sir Roderick Murchison, who named it after the region of Perm in Russia. The Permian witnessed the diversification of the two groups of amniotes, the synapsids and the sauropsids (reptiles). The world at the time was dominated by the supercontinent Pangaea, which had formed due to the collision of Euramerica and Gondwana during the Carboniferous. Pangaea was surrounded by the superocean Panthalassa. The Carboniferous rainforest collapse left behind vast regions of desert within the continental interior. Amniotes, which could better cope with these drier conditions, rose to dominance in place of their amphibian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carboniferous Sharks
The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carboniferous'' means "coal-bearing", from the Latin '' carbō'' ("coal") and '' ferō'' ("bear, carry"), and refers to the many coal beds formed globally during that time. The first of the modern 'system' names, it was coined by geologists William Conybeare and William Phillips in 1822, based on a study of the British rock succession. The Carboniferous is often treated in North America as two geological periods, the earlier Mississippian and the later Pennsylvanian. Terrestrial animal life was well established by the Carboniferous Period. Tetrapods (four limbed vertebrates), which had originated from lobe-finned fish during the preceding Devonian, became pentadactylous in and diversified during the Carboniferous, including early amphibian lineages ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Egg Fossils
Egg fossils are the fossilized remains of eggs laid by ancient animals. As evidence of the physiological processes of an animal, egg fossils are considered a type of trace fossil. Under rare circumstances a fossil egg may preserve the remains of the once- developing embryo inside, in which case it also contains body fossils. A wide variety of different animal groups laid eggs that are now preserved in the fossil record beginning in the Paleozoic. Examples include invertebrates like ammonoids as well as vertebrates like fishes, possible amphibians, and reptiles. The latter group includes the many dinosaur eggs that have been recovered from Mesozoic strata. Since the organism responsible for laying any given egg fossil is frequently unknown, scientists classify eggs using a parallel system of taxonomy separate from but modeled after the Linnaean system. This "parataxonomy" is called ''veterovata''. History The first named oospecies was '' Oolithes bathonicae'', a name given provisi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertebrate Trace Fossils
Vertebrates () comprise all animal taxon, taxa within the subphylum Vertebrata () (chordates with vertebral column, backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, with currently about 69,963 species described. Vertebrates comprise such groups as the following: * Agnatha, jawless fish, which include hagfish and lampreys * Gnathostomata, jawed vertebrates, which include: ** Chondrichthyes, cartilaginous fish (sharks, Batoidea, rays, and Chimaeriformes, ratfish) ** Euteleostomi, bony vertebrates, which include: *** Actinopterygii, ray-fins (the majority of living Osteichthyes, bony fish) *** lobe-fins, which include: **** coelacanths and lungfish **** tetrapods (limbed vertebrates) Extant taxon, Extant vertebrates range in size from the frog species ''Paedophryne amauensis'', at as little as , to the blue whale, at up to . Vertebrates make up less than five percent of all described a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Vertebrate Paleontology
The ''Journal of Vertebrate Paleontology'' is a bimonthly peer-reviewed scientific journal that was established in 1980 by Jiri Zidek (University of Oklahoma). It covers all aspects of vertebrate paleontology, including vertebrate origins, evolution, functional morphology, taxonomy, biostratigraphy, paleoecology, paleobiogeography, and paleoanthropology. The journal is published by Taylor & Francis on behalf of the Society of Vertebrate Paleontology. According to ''Journal Citation Reports'', the journal has a 2017 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as i ... of 2.190. References External links * Paleontology journals Publications established in 1980 Quarterly journals English-language journals Taylor & Francis academic journals {{paleontology-jou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freiberger Forschungshefte
The Freiberger, also known as Franches-Montagnes, is a horse breed from Switzerland, from the Jura region, described as either a "heavy warmblood" or a "light coldblood". It was widely used as draft and pack horse in the Swiss army. It has a good disposition and is versatile, suitable for both driving and riding. Each year at the ''Marché Concours'' in Saignelégier in the Franches-Montagnes district of the Swiss canton of Jura, on the second weekend in August, a variety of shows and competitions are held. Breed characteristics History The presence of an autochthonous horse breed in the Jura traces to the year 1619. By the early 19th century, there were active breeders in the district of Franches-Montagnes. In 1817, there were 4,000 breeding mares on record. The horses were bred for use in agriculture and by the army as pack animals and artillery draft horses. There are records of imports of Anglo-Norman horses for the year 1821, and of other horses from England, Fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xyris
''Xyris'' is a genus of flowering plants, the yelloweyed grasses, in the yellow-eyed-grass family. The genus counts over 250 species, widespread over much of the world, with the center of distribution in the Guianas. The leaves are mostly distichous, linear, flat, and thin or round with a conspicuous sheath at the base. They are arranged in a basal aggregation. The small, yellow flowers are borne on a spherical or cylindrical spike or head (inflorescence). Each flower grows from the axil of a leathery bract. The fruit is a nonfleshy, dehiscent capsule. In ''Xyris complanata'', a single flower bud on the spike appears in the morning, and expands into a conspicuous flower during the afternoon hours. The APG IV system, of 2016, places the genus in family Xyridaceae, into the order Poales in the clade commelinids, in the monocots Monocotyledons (), commonly referred to as monocots, (Lilianae ''sensu'' Chase & Reveal) are grass and grass-like flowering plants (angiosperms), th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
