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Equisetum Dimorphum
''Equisetum dimorphum'' is an extinct horsetail species of the family Equisetaceae, and one of the oldest records of the genus ''Equisetum''. It was found in rocks from the Lower Jurassic of Chubut, Argentina, among other plants as ferns, conifers and pteridosperms. Their remains consist of stems, leaves, strobili, and pagoda structures, which are preserved as impressions and casts. The combination of fine grained sediment, and the probable silica deposits in the epidermis of the plant, have managed to conserve not only its gross morphology, but also epidermal details not often present in this kind of preservation. This species was described in 2015 in Ameghiniana by a team led by Andres Elgorriaga, that included investigators of the Museum of Paleontology Egidio Feruglio, the Swedish Museum of Natural History, and the Buenos Aires University. Description The stems are dimorphic, unbranched and present no sign of superficial ribs and valleys. They are hollow except at the nodal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pliensbachian
The Pliensbachian is an age of the geologic timescale and stage in the stratigraphic column. It is part of the Early or Lower Jurassic Epoch or Series and spans the time between 190.8 ± 1.5 Ma and 182.7 ± 1.5 Ma (million years ago). The Pliensbachian is preceded by the Sinemurian and followed by the Toarcian. The Pliensbachian ended with the extinction event called the Toarcian turnover. During the Pliensbachian, the middle part of the Lias was deposited in Europe. The Pliensbachian is roughly coeval with the Charmouthian regional stage of North America. Stratigraphic definitions The Pliensbachian takes its name from the hamlet of Pliensbach in the community of Zell unter Aichelberg in the Swabian Alb, some 30 km east of Stuttgart in Germany. The name was introduced into scientific literature by German palaeontologist Albert Oppel in 1858. The base of the Pliensbachian is at the first appearances of the ammonite species '' Bifericeras donovani'' and genera ''Apoderocer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buenos Aires University
The University of Buenos Aires ( es, Universidad de Buenos Aires, UBA) is a public university, public research university in Buenos Aires, Argentina. Established in 1821, it is the premier institution of higher learning in the country and one of the most prestigious universities of Ibero-America. It has educated 17 President of Argentina, Argentine presidents, produced four of the country's five Nobel Prize laureates, and is responsible for approximately 40% of the country's research output. The ''QS World University Rankings'' currently places the UBA at number 67, the highest ranking university in the Spanish-speaking world. The university's academic strength and regional leadership make it attractive to many international students, especially at the postgraduate level. Just over 4 percent of undergraduates are foreigners, while 15 percent of postgraduate students come from abroad. The Faculty of Economic Sciences, University of Buenos Aires, Faculty of Economic Sciences has t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossils Of Argentina
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. Early edition, published online before print. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the absolute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flora Of Argentina
The Environment of Argentina is characterised by high biodiversity. Biodiversity Subtropical plants dominate the Gran Chaco in the north, with the ''Dalbergia'' genus of trees well represented by Brazilian rosewood and the quebracho tree; also predominant the wacho white and black algarrobo trees ('' Prosopis alba'' and ''Prosopis nigra''). Savannah-like areas exist in the drier regions nearer the Andes. Aquatic plants thrive in the wetlands of Argentina. In central Argentina the ''humid pampas'' are a true tallgrass prairie ecosystem. The original pampa had virtually no trees; some imported species like the American sycamore or eucalyptus are present along roads or in towns and country estates (''estancias''). The only tree-like plant native to the pampa is the evergreen Ombú. The surface soils of the pampa are a deep black color, primarily mollisols, known commonly as ''humus''. This makes the region one of the most agriculturally productive on Earth; however, this is also res ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic Argentina
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, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Plants Of South America
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. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic Plants
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] |
Equisetum Thermale
''Equisetum thermale'' is an extinct horsetail species in the family Equisetaceae described from a group of whole plant fossils including rhizomes, stems, and leaves. The species is known from Middle to Late Jurassic sediments exposed in the province of Santa Cruz, Argentina. It is one of several extinct species placed in the living genus ''Equisetum''. History and classification ''Equisetum thermale'' is represented by a series of fossil specimens preserved in hot springs deposits preserved in the Callovian to Tithonian aged La Matilde Formation. The group is part of the Bahía Laura Group exposed in the northwestern region of the Deseado Massif. The formations is the result of Jurassic age fault generated valleys filled by lacustrian infilling and hydrothermal activity represented by epithermal deposits. One such hot spring deposit, the San Agustín hot spring complex was reported in 2010 and is noted for the preservation of plants growing around the complex by silicif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equisetum Hyemale
''Equisetum hyemale'' (commonly known as rough horsetail, scouring rush, scouringrush horsetail and, in South Africa, as snake grass) is a perennial herbaceous vascular plant in the horsetail family Equisetaceae. It is a native plant throughout the Holarctic Kingdom, found in North America, Europe, and northern Asia. Distribution In nature ''Equisetum hyemale'' grows in mesic (reliably moist) habitats, often in sandy or gravelly areas. It grows from between sea level to in elevation. It is primarily found in wetlands, and in riparian zones of rivers and streams where it can withstand seasonal flooding. It is also found around springs and seeps, and can indicate their presence when not flowing. Other habitats include moist forest and woodland openings, lake and pond shores, ditches, and marshes and swamps. Description ''Equisetum hyemale'' has vertical jointed reed-like stalks of medium to dark green. The hollow stems are up to in height. The stems are seldom branched. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swedish Museum Of Natural History
The Swedish Museum of Natural History ( sv, Naturhistoriska riksmuseet, literally, the National Museum of Natural History), in Stockholm, is one of two major museums of natural history in Sweden, the other one being located in Gothenburg. The museum was founded in 1819 by the Royal Swedish Academy of Sciences, but goes back to the collections acquired mostly through donations by the academy since its foundation in 1739. These collections had first been made available to the public in 1786. The museum was separated from the Academy in 1965. One of the keepers of the collections of the academy during its earlier history was Anders Sparrman, a student of Carl Linnaeus and participant in the voyages of Captain James Cook. Another important name in the history of the museum is the zoologist, paleontologist and archaeologist Sven Nilsson, who brought the previously disorganised zoological collections of the museum into order during his time as keeper (1828–1831) before returning t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equisetaceae
Equisetaceae, sometimes called the horsetail family, is the only extant family of the order Equisetales, with one surviving genus, ''Equisetum'', which comprises about twenty species. Evolution and systematics Equisetaceae is the only surviving family of the Equisetales, a group with many fossils of large tree-like plants that possessed ribbed stems similar to modern horsetails. '' Pseudobornia'' is the oldest known relative of ''Equisetum''; it grew in the late Devonian, about 375 million years ago and is assigned to its own order. All living horsetails are placed in the genus ''Equisetum''. But there are some fossil species that are not assignable to the modern genus. ''Equisetites'' is a "wastebin taxon" uniting all sorts of large horsetails from the Mesozoic; it is almost certainly paraphyletic and would probably warrant being subsumed in ''Equisetum''. But while some of the species placed there are likely to be ancestral to the modern horsetails, there have been reports of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Museum Of Paleontology Egidio Feruglio
The Museum of Paleontology Egidio Feruglio (MEF, in es, Museo Paleontológico Egidio Feruglio) is a science research and exhibition center in Trelew city, Patagonia, Argentina. Its permanent and travelling exhibitions focus on the fossil remains of fauna and flora of Patagonia, and the changes that affected the region over geological time. The museum is named for geologist Egidio Feruglio. MEF is one of Argentina's main scientific institutions, with a robust research program in areas including vertebrate and invertebrate paleontology, paleobotany, and ichnology, and has a group focusing on plants in semi-desert environments. MEF exhibitions MEF's permanent exhibition is a journey into the natural past of Patagonia. It begins about 10,000 years ago, with the first human settlements in the area. In each room, specimens from both terrestrial and marine life forms are shown for each geological period, up to the early Paleozoic. The Mesozoic hall depicting the giant dinosaurs of P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
