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Meizonyx
''Meizonyx'' is an extinct genus of megalonychid ground sloth from the Pleistocene of El Salvador and southern Mexico. The type and only species, ''Meizonyx salvadorensis,'' was described in 1985 from a mandible found in Barranca del Sisimico and other remains found at Rio Tomayate in El Salvador considered to be Middle Pleistocene in age. Later, in 2021, additional remains were described from Late Pleistocene aged deposits in Sistema Huautla Sistema Huautla is a cave system in the Sierra Mazateca mountains of the southern Mexican state of Oaxaca. it was the deepest cave system in the Western Hemisphere, from top to bottom, with over 55 miles of mapped passageways. Location Siste ..., Oxaca, Mexico. It is considered closely related to '' Xibalbaonyx.'' References {{Taxonbar, from=Q58418070 Prehistoric sloths Pleistocene xenarthrans Prehistoric placental genera Holocene extinctions Rancholabrean Pleistocene Mexico Fossils of Mexico Fossil taxa described in 198 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megalonychidae
Megalonychidae is an extinct family of sloths including the extinct ''Megalonyx''. Megalonychids first appeared in the early Oligocene, about 35 million years (Ma) ago, in southern Argentina (Patagonia). There is actually one possible find dating to the Eocene, about 40 Ma ago, on Seymour Island in Antarctica (which was then still connected to South America). They first reached North America by island-hopping across the Central American Seaway, about 9 million years ago, prior to formation of the Isthmus of Panama about 2.7 million years ago (which led to the main pulse of the Great American Interchange). Some megalonychid lineages increased in size as time passed. The first species of these were small and may have been partly tree-dwelling, whereas the Pliocene (about 5 to 2 million years ago) species were already approximately half the size of the huge Late Pleistocene ''Megalonyx jeffersonii'' from the last ice age.J.L. White (1993) It was formerly believed, based on morpholo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground Sloth
Ground sloths are a diverse group of extinct sloths in the mammalian superorder Xenarthra. The term is used to refer to all extinct sloths because of the large size of the earliest forms discovered, compared to existing tree sloths. The Caribbean ground sloths, the most recent survivors, lived in the Antilles, possibly until 1550 BCE. However, radiocarbon dating suggests an age of between 2819 and 2660 BCE for the last occurrence of ''Megalocnus'' in Cuba. Ground sloths had been extinct on the mainland of North and South America for 10,000 years or more. They survived 5,000–6,000 years longer in the Caribbean than on the American mainland, which correlates with the later colonization of this area by humans. Much ground sloth evolution took place during the late Paleogene and Neogene of South America, while the continent was isolated. At their earliest appearance in the fossil record, the ground sloths were already distinct at the family level. The presence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
El Salvador
El Salvador (; , meaning " The Saviour"), officially the Republic of El Salvador ( es, República de El Salvador), is a country in Central America. It is bordered on the northeast by Honduras, on the northwest by Guatemala, and on the south by the Pacific Ocean. El Salvador's capital and largest city is San Salvador. The country's population in 2022 is estimated to be 6.5 million. Among the Mesoamerican nations that historically controlled the region are the Lenca (after 600 AD), the Mayans, and then the Cuzcatlecs. Archaeological monuments also suggest an early Olmec presence around the first millennium BC. In the beginning of the 16th century, the Spanish Empire conquered the Central American territory, incorporating it into the Viceroyalty of New Spain ruled from Mexico City. However the Viceroyalty of Mexico had little to no influence in the daily affairs of the isthmus, which was colonized in 1524. In 1609, the area was declared the Captaincy General of Guatemala by t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatemala, Belize, and the Caribbean Sea; and to the east by the Gulf of Mexico. Mexico covers ,Mexico ''''. . making it the world's 13th-largest country by are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Pleistocene
The Chibanian, widely known by its previous designation of Middle Pleistocene, is an age in the international geologic timescale or a stage in chronostratigraphy, being a division of the Pleistocene Epoch within the ongoing Quaternary Period. The Chibanian name was officially ratified in January 2020. It is currently estimated to span the time between 0.770 Ma (770,000 years ago) and 0.126 Ma (126,000 years ago), also expressed as 770–126 ka. It includes the transition in palaeoanthropology from the Lower to the Middle Palaeolithic over 300 ka. The Chibanian is preceded by the Calabrian and succeeded by the proposed Tarantian. The beginning of the Chibanian is the Brunhes–Matuyama reversal, when the Earth's magnetic field last underwent reversal. It ends with the onset of the Eemian interglacial period (Marine Isotope Stage 5). The term Middle Pleistocene was in use as a provisional or "quasi-formal" designation by the International Union of Geological Sciences (IUGS). W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sistema Huautla
Sistema Huautla is a cave system in the Sierra Mazateca mountains of the southern Mexican state of Oaxaca. it was the deepest cave system in the Western Hemisphere, from top to bottom, with over 55 miles of mapped passageways. Location Sistema Huautla is a cave system in the Sierra Mazateca mountains in the Teotitlán District of the Cañada region in the southern Mexico state of Oaxaca. It is below the municipalities of Huautla de Jimenez, Huautepec and Mazatlan Villa de Flores. it was long (end to end) with 25 distinct entrances and a depth measurement of from its highest known entrance to its lowest reached point. System Huautla is the deepest cave in the Western Hemisphere and the tenth deepest cave in the world; it is listed as the twenty-eighth longest at about 55.3 miles surveyed passage compared to the Mammoth Cave complex at 420+ miles. History In 1965 cavers from Austin, Texas exploring the Sierra Mazateca mountains found several large caves; During the 1960 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xibalbaonyx
''Xibalbaonyx'' is an extinct genus of megalonychid ground sloth known from the Late Pleistocene of Mexico. Three species are known: ''X. oviceps'' and ''X. exiniferis'' from the Yucatan peninsula and ''X. microcaninus'' from Jalisco. The genus is named after Xibalba, the underworld in Maya mythology. Discovery and taxonomy The holotype of ''X. oviceps'' is a mostly complete skeleton discovered in an underwater cave system, while ''X. microcaninus'' being known from a complete skull and mandible from the sediments of the former paleolake of lake Jalisco. The overlapping remains of the skull and mandibles have notable differences between them, enough to call them distinct species. A third species ''X. exiniferis'' was described in 2020, also from an underwater cave in the Yucatan Peninsula, it is known from a "fragmentary left mandibular ramus, an atlas, and a left humerus". In 2020, a description of the postcranial remains of the holotype ''X. oviceps'' was published, suggest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Sloths
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] |
Pleistocene Xenarthrans
The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in 2009 by the International Union of Geological Sciences, the cutoff of the Pleistocene and the preceding Pliocene was regarded as being 1.806 million years Before Present (BP). Publications from earlier years may use either definition of the period. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology. The name is a combination of Ancient Greek grc, label=none, πλεῖστος, pleīstos, most and grc, label=none, καινός, kainós (latinized as ), 'new'. At the end of the preceding Pliocene, the previously isolated North and South American continents were joined by the Isthmus of Panama, causing a faunal interchange between the two reg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Placental Genera
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] |
Holocene Extinctions
The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene together form the Quaternary period. The Holocene has been identified with the current warm period, known as MIS 1. It is considered by some to be an interglacial period within the Pleistocene Epoch, called the Flandrian interglacial.Oxford University Press – Why Geography Matters: More Than Ever (book) – "Holocene Humanity" section https://books.google.com/books?id=7P0_sWIcBNsC The Holocene corresponds with the rapid proliferation, growth and impacts of the human species worldwide, including all of its written history, technological revolutions, development of major civilizations, and overall significant transition towards urban living in the present. The human impact on modern-era Earth and its ecosystems may be considered of global sig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rancholabrean
The Rancholabrean North American Land Mammal Age on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from less than 240,000 years to 11,000 years BP, a period of .Sanders, A.E., R.E. Weems, and L.B. Albright III (2009) Formalization of the mid-Pleistocene "Ten Mile Hill beds" in South Carolina with evidence for placement of the Irvingtonian–Rancholabrean boundary, ''Museum of Northern Arizona Bulletin'' 64:369-375 Named after the famed Rancho La Brea fossil site (more commonly known as the La Brea tar pits) in Los Angeles, California,Savage, D.E. (1951) Late Cenozoic vertebrates of the San Francisco Bay region, ''University of California Publications, Bulletin of the Department of Geological Sciences'' 28:215-314 the Rancholabrean is characterized by the presence of the genus '' Bison'' in a Pleistocene context, often in association with other extinct Pleistocene forms such as ''Mammuth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
