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Llankibatrachus
''Llankibatrachus'' is an extinct genus of prehistoric frogs in the family Pipidae. They are known from the Ypresian In the geologic timescale the Ypresian is the oldest age or lowest stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by the Eocene Lutetian Age. The Ypresian i ... (Casamayoran) Huitrera Formation of Argentina. Description The type species and the only known species, ''Llankibatrachus truebae'', is named after Linda Trueb, a herpetologist from the University of Kansas. The species is known from two deposits near the Nahuel Huapi Lake in north-western Patagonia, Argentina. The finds include nearly complete specimens with impressions of skin, and individuals of different developmental stages, including tadpoles. See also * Prehistoric amphibian * List of prehistoric amphibians References Pipidae, † Paleogene amphibians Eocene animals of South America Casamayoran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Huitrera Formation
The Huitrera Formation is a geological formation in the Neuquén Basin in northern Patagonian Argentina whose strata date back to the Early Eocene of the Paleogene, or Casamayoran in the South American land mammal age classification. Description The Huitrera Formation was first defined by Ravazzoli and Sesana in 1977. The name has been used to identify various volcaniclastic sequences, among others in the Ñirihuau fold-and-thrust belt.Escosteguy & Franchi, 2010, p.420 The up to thick formation comprises mudstones and sandstones deposited in a crater lake environment. Part of the formation comprises andesites, dacitic and rhyolitic ignimbrites, volcanic breccias, tuffs and trachybasalts.Prez & Massafero, 2013, p.228 The formation was initially described as Late Eocene to Early Oligocene, but was later dated to 54.24 ± 0.45 Ma, meaning the Huitrera Formation is Ypresian, or in the SALMA classification, Casamayoran in age. Fossil content The following macrofossils were r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Casamayoran
The Casamayoran ( es, Casamayorense) age is a period of geologic time (50.0–48.0 Ma) within the Early Eocene epoch of the Paleogene, used more specifically within the South American land mammal age (SALMA) classification. It follows the Itaboraian and precedes the Mustersan age. Several astrapotherian mammals are known from this period, such as '' Antarctodon'' and ''Albertogaudrya'' from Antarctica and Argentina, respectively. ''Albertogaudrya'' and '' Scaglia'' were the size of a sheep or a small tapir, hence among the larger mammals in South America at this time.Rose, 2006, p.236 Etymology This age is named after the Casamayor Formation of the Golfo San Jorge Basin The Golfo San Jorge Basin ( es, Cuenca del Golfo San Jorge) is a hydrocarbon-rich sedimentary basin located in eastern Patagonia, Argentina. The basin covers the entire San Jorge Gulf and an inland area west of it, having one half located in Sant .... Formations Fossils References Bibliography ; ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Amphibian
This list of prehistoric amphibians is an attempt to create a comprehensive listing of all genera from the fossil record that have ever been considered to be amphibians, excluding purely vernacular terms. The list includes all commonly accepted genera, but also genera that are now considered invalid, doubtful (''nomina dubia''), or were not formally published ('' nomina nuda''), as well as junior synonyms of more established names, and genera that are no longer considered amphibians. Modern forms are excluded from this list. The list currently includes 454 names. Naming conventions and terminology Naming conventions and terminology follow the International Code of Zoological Nomenclature. Technical terms used include: * Junior synonym: A name which describes the same taxon as a previously published name. If two or more genera are formally designated and the type specimens are later assigned to the same genus, the first to be published (in chronological order) is the senior synon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pipidae
The Pipidae are a family of primitive, tongueless frogs. The 41 species in the family Pipidae are found in tropical South America (genus ''Pipa'') and sub-Saharan Africa (the three other genera). Description Pipid frogs are highly aquatic and have numerous morphological modifications befitting their habitat. For example, the feet are completely webbed, the body is flattened, and a lateral line system is present in adults. In addition, pipids possess highly modified ears for producing and receiving sound under water. They lack a tongue or vocal cords, instead having bony rods in the larynx that help produce sound. They range from in body length. Taxonomy Family Pipidae * '' Hymenochirus'' - dwarf clawed frogs (4 species) * ''Pipa'' - Surinam toads (7 species) * '' Pseudhymenochirus'' - Merlin's dwarf gray frog or Merlin's clawed frog (1 species) * ''Xenopus'' - clawed frogs (29 species)Evans et al., 2015 ** Subgenus ''( Silurana)'' - common clawed frogs ** Subgenus ''( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Prehistoric Amphibians
This list of prehistoric amphibians is an attempt to create a comprehensive listing of all genera from the fossil record that have ever been considered to be amphibians, excluding purely vernacular terms. The list includes all commonly accepted genera, but also genera that are now considered invalid, doubtful (''nomina dubia''), or were not formally published ('' nomina nuda''), as well as junior synonyms of more established names, and genera that are no longer considered amphibians. Modern forms are excluded from this list. The list currently includes 454 names. Naming conventions and terminology Naming conventions and terminology follow the International Code of Zoological Nomenclature. Technical terms used include: * Junior synonym: A name which describes the same taxon as a previously published name. If two or more genera are formally designated and the type specimens are later assigned to the same genus, the first to be published (in chronological order) is the senior synon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ypresian
In the geologic timescale the Ypresian is the oldest age or lowest stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by the Eocene Lutetian Age. The Ypresian is consistent with the lower Eocene. Events The Ypresian Age begins during the throes of the Paleocene–Eocene Thermal Maximum (PETM). The Fur Formation in Denmark, the Messel shales in Germany, the Oise amber of France and Cambay amber of India are of this age. The Eocene Okanagan Highlands are an uplands subtropical to temperate series of lakes from the Ypresian. Stratigraphic definition The Ypresian Stage was introduced in scientific literature by Belgian geologist André Hubert Dumont in 1850. The Ypresian is named after the Flemish city of Ypres in Belgium (spelled ''Ieper'' in Dutch). The definitions of the original stage were totally different from the modern ones. The Ypresian shares its name with the Belgian Ieper Group (French: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene Argentina
The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', "dawn") and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch. The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a brief period in which the concentration of the carbon isotope 13C in the atmosphere was exceptionally low in comparison with the more common isotope 12C. The end is set at a major extinction event called the ''Grande Coupure'' (the "Great Break" in continuity) or the Eocene–Oligocene extinction event, which may be related to the impact of one or more large bolides in Siberia and in what is now Chesapeake Bay. As with other geologic periods, the strata that define the start and end of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ypresian Life
In the geologic timescale the Ypresian is the oldest age or lowest stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by the Eocene Lutetian Age. The Ypresian is consistent with the lower Eocene. Events The Ypresian Age begins during the throes of the Paleocene–Eocene Thermal Maximum (PETM). The Fur Formation in Denmark, the Messel shales in Germany, the Oise amber of France and Cambay amber of India are of this age. The Eocene Okanagan Highlands are an uplands subtropical to temperate series of lakes from the Ypresian. Stratigraphic definition The Ypresian Stage was introduced in scientific literature by Belgian geologist André Hubert Dumont in 1850. The Ypresian is named after the Flemish city of Ypres in Belgium (spelled ''Ieper'' in Dutch). The definitions of the original stage were totally different from the modern ones. The Ypresian shares its name with the Belgian Ieper Group (Fre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene Animals Of South America
The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', "dawn") and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch. The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a brief period in which the concentration of the carbon isotope 13C in the atmosphere was exceptionally low in comparison with the more common isotope 12C. The end is set at a major extinction event called the ''Grande Coupure'' (the "Great Break" in continuity) or the Eocene–Oligocene extinction event, which may be related to the impact of one or more large bolides in Siberia and in what is now Chesapeake Bay. As with other geologic periods, the strata that define the start and end of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleogene Amphibians
The Paleogene ( ; also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period million years ago ( Mya) to the beginning of the Neogene Period Mya. It is the beginning of the Cenozoic Era of the present Phanerozoic Eon. The earlier term Tertiary Period was used to define the span of time now covered by the Paleogene Period and subsequent Neogene Period; despite no longer being recognised as a formal stratigraphic term, 'Tertiary' is still widely found in earth science literature and remains in informal use. Paleogene is often abbreviated "Pg" (but the United States Geological Survey uses the abbreviation PE for the Paleogene on the Survey's geologic maps). During the Paleogene, mammals diversified from relatively small, simple forms into a large group of diverse animals in the wake of the Cretaceous–Paleogene extinction event that ended the preceding Cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nahuel Huapi Lake
Nahuel Huapi Lake ( es, Lago Nahuel Huapí) is a lake in the lake region of northern Patagonia between the provinces of Río Negro and Neuquén, in Argentina. The tourist center of Bariloche is on the southern shore of the lake. The June 2011 eruption of the Puyehue-Cordón Caulle volcanic complex, in neighboring Chile, caused parts of the lake's surface to be blanketed in volcanic ash. During the Last Glacial Maximum of the Llanquihue glaciation the lake basin was wholly occupied by a glacier. Etymology The name of the lake derives from the toponym of its major island in Mapudungun (Mapuche language): "Island of Puma", from ''nahuel'', 'puma', and ''huapí'', 'island'. There is, however, more to the word "Nahuel"—it can also signify 'a man who by sorcery has been transformed to a puma'. Geography Nahuel Huapi lake, located within the Nahuel Huapi National Park, has a surface of , rests above the sea level, and has a maximum measured depth (as of 2007) of . The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tadpole
A tadpole is the larval stage in the biological life cycle of an amphibian. Most tadpoles are fully aquatic, though some species of amphibians have tadpoles that are terrestrial. Tadpoles have some fish-like features that may not be found in adult amphibians such as a lateral line, gills and swimming tails. As they undergo metamorphosis, they start to develop functional lungs for breathing air, and the diet of tadpoles changes drastically. A few amphibians, such as some members of the frog family Brevicipitidae, undergo direct development i.e., they do not undergo a free-living larval stage as tadpoles instead emerging from eggs as fully formed "froglet" miniatures of the adult morphology. Some other species hatch into tadpoles underneath the skin of the female adult or are kept in a pouch until after metamorphosis. Having no hard skeletons, it might be expected that tadpole fossils would not exist. However, traces of biofilms have been preserved and fossil tadpol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
