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Hans Thewissen
Hans Thewissen is a Dutch-American paleontologist. His field work has discovered fossils for the steps in the transition from land to water in whales: '' Ambulocetus'', '' Pakicetus'', ''Indohyus'' and '' Kutchicetus''. He now studies modern bowhead and beluga whales in Alaska to learn about their biology and their implications for management and conservation. Early life Thewissen has always been interested in paleontology and natural history. His mother said that when Thewissen was a small boy, she had to sort through his pockets before laundry time to take out the rocks and worms he collected. His father used to take him to the town of Maastricht, and they collected fossils from the Maastrichtian period. 12th birthday present was a rock hammer, which has accompanied him on all collecting trips since. He grew up just 2 miles from Liessel, a fossil locale that yielded the first whales he ever collected. Educational background After finishing Gymnasium secondary education in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herkenbosch
Roerdalen (; li, Roerdale ) is a municipality in the southeastern Netherlands, in the province of Limburg. As of , it had about inhabitants and borders Germany. Roerdalen is the renaming of the municipality of Melick en Herkenbosch in 1993. Population centres Topography ''Dutch Topographic map of the municipality of Roerdalen, June 2015'' Notable people * Hubert Biermans (1864 in Herkenbosch - 1953) a Dutch and Canadian businessman * Connie Palmen (born 1955 in Sint Odiliënberg) a Dutch author * Geert Chatrou (born 1969 in Sint Odiliënberg) a professional whistler * Jos Verstappen (born 1972 in Montfort) a Dutch former racing driver * Joeri Verlinden (born 1988 in Melick) a Dutch swimmer, competed at the 2016 Summer Olympics Gallery Image:Sint Odiliënberg, molen foto5 2011-03-16 11.40.JPG, Windmill (molen van Verbeek) in Sint Odiliënberg Image:Melick2.jpg, River Roer The Rur or Roer (german: Rur ; Dutch and li, Roer, , ; french: Rour) is a major river that flo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bowhead Whale
The bowhead whale (''Balaena mysticetus'') is a species of baleen whale belonging to the family Balaenidae and the only living representative of the genus ''Balaena''. They are the only baleen whale endemic to the Arctic and subarctic waters, and are named after their characteristic massive triangular skull, which they use to break through Arctic ice. Other common names of the species are the Greenland right whale, Arctic whale, and Arviq in aboriginal languages ( Inuktitut). American whalemen called them the steeple-top, polar whale, or Russian whale. Bowheads have the largest mouth of any animal representing almost one-third of the length of the body, the longest baleen plates with a maximum length of and may be the longest-lived mammals, with the ability to reach an age of more than 200 years. The bowhead was an early whaling target. Their population was severely reduced before a 1966 moratorium was passed to protect the species. Of the five stocks of bowhead population ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesonychids
Mesonychia ("middle claws") is an extinct taxon of small- to large-sized carnivorous ungulates related to artiodactyls. Mesonychids first appeared in the early Paleocene, went into a sharp decline at the end of the Eocene, and died out entirely when the last genus, ''Mongolestes'', became extinct in the early Oligocene. In Asia, the record of their history suggests they grew gradually larger and more predatory over time, then shifted to scavenging and bone-crushing lifestyles before the group became extinct. Mesonychids probably originated in China, where the most primitive mesonychid, ''Yangtanglestes'', is known from the early Paleocene. They were also most diverse in Asia, where they occur in all major Paleocene faunas. Since other predators, such as creodonts and Carnivora, were either rare or absent in these animal communities, mesonychids most likely dominated the large predator niche in the Paleocene of eastern Asia. One genus, ''Dissacus'', had successfully spread to Eur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Artiodactyls
The even-toed ungulates (Artiodactyla , ) are ungulates—hoofed animals—which bear weight equally on two (an even number) of their five toes: the third and fourth. The other three toes are either present, absent, vestigial, or pointing posteriorly. By contrast, odd-toed ungulates bear weight on an odd number of the five toes. Another difference between the two is that many other even-toed ungulates (with the exception of Suina) digest plant cellulose in one or more stomach chambers rather than in their intestine as the odd-toed ungulates do. Cetaceans (whales, dolphins, and porpoises) evolved from even-toed ungulates, and are therefore often classified under the same taxonomic branch because a species cannot outgrow its evolutionary ancestry; some modern taxonomists combine the two under the name Cetartiodactyla , while others opt to include cetaceans in the already-existing Artiodactyla. The roughly 270 land-based even-toed ungulate species include pigs, peccaries, hippopota ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Condylarths
Condylarthra is an informal group – previously considered an order – of extinct placental mammals, known primarily from the Paleocene and Eocene epochs. They are considered early, primitive ungulates. It is now largely considered to be a wastebasket taxon, having served as a dumping ground for classifying ungulates which had not been clearly established as part of either Perissodactyla or Cetartiodactyla, being composed thus of several unrelated lineages. Taxonomic history Condylarthra always was a problematic group. When Condylarthra was first described by , Phenacodontidae was the type and only family therein. , however, raised Condylarthra to an order and included a wide range of diverse placentals with generalized dentitions and postcranial skeletons. More recent researchers (i.e. post-WW2) have been more restrictive; either including only a limited number of taxa, or proposing that the term should be abandoned altogether. Due to their primitive characteristics condylar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ungulate
Ungulates ( ) are members of the diverse clade Ungulata which primarily consists of large mammals with hooves. These include odd-toed ungulates such as horses, rhinoceroses, and tapirs; and even-toed ungulates such as cattle, pigs, giraffes, camels, sheep, deer, and hippopotamuses. Cetaceans such as whales, dolphins, and porpoises are also classified as even-toed ungulates, although they do not have hooves. Most terrestrial ungulates use the hoofed tips of their toes to support their body weight while standing or moving. The term means, roughly, "being hoofed" or "hoofed animal". As a descriptive term, "ungulate" normally excludes cetaceans as they do not possess most of the typical morphological characteristics of other ungulates, but recent discoveries indicate that they were also descended from early artiodactyls. Ungulates are typically herbivorous and many employ specialized gut bacteria to allow them to digest cellulose. Some modern species, such as pigs, are omnivorous, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleogene
The Paleogene ( ; British English, also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period, geologic period and system that spans 43 million years from the end of the Cretaceous Period million years ago (annum, 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 stratigraphy, 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, evolution of mammals, mammals diversified from relatively small, simple forms into a large group of diverse animals in the wake of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenacodontid
Phenacodontidae is an extinct family of large herbivorous mammals traditionally placed in the “wastebasket taxon” Condylarthra, which may instead represent early-stage perissodactyls. They lived in the Paleocene and Eocene epochs (about 60–50 million years ago) and their fossil remains have been found in North America and Europe. Description These animals had a variety of body sizes, and could be as small as domestic cats (''Tetraclaenodon'' and ''Ectocion'') and as large as sheep (''Phenacodus''). The skull of phenacodontids is long and narrow, and equipped with a small braincase. The skeleton of phenacodontids show several primitive characteristics (the long and heavy tail for example) but also a number of advanced, Perissodactyla-like adaptations: Their long legs, for example, had five fingers, but the first finger showed a clear reduction, and in some forms (like ''Phenacodus'') the fifth finger was reduced as well. Some species had tapir-like adaptations suggest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Museum Of Natural History (France)
The National Museum of Natural History is a natural history museum administered by the Smithsonian Institution, located on the National Mall in Washington, D.C., United States. It has free admission and is open 364 days a year. In 2021, with 7.1 million visitors, it was the list of most visited museums, eighteenth most visited museum in the world and the second most visited natural history museum in the world after the Natural History Museum, London, Natural History Museum in London."The World's most popular museums", CNN.com, 22 June 2017. Opened in 1910, the museum on the National Mall was one of the first Smithsonian buildings constructed exclusively to hold the national collections and research facilities. The main building has an overall area of with of exhibition and public space and houses over 1,000 employees. The museum's collections contain over 145 million specimens of plants, animals, fossils, minerals, rock (geology), rocks, meteorites, human remains, and human c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene
The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), 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 Carbon-13, 13C in the atmosphere was exceptionally low in comparison with the more common isotope Carbon-12, 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 Popigai impact structure, Siberia and in what is now ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gymnasium (school)
''Gymnasium'' (and variations of the word) is a term in various European languages for a secondary school that prepares students for higher education at a university. It is comparable to the US English term '' preparatory high school''. Before the 20th century, the gymnasium system was a widespread feature of educational systems throughout many European countries. The word (), from Greek () 'naked' or 'nude', was first used in Ancient Greece, in the sense of a place for both physical and intellectual education of young men. The latter meaning of a place of intellectual education persisted in many European languages (including Albanian, Bulgarian, Estonian, Greek, German, Hungarian, the Scandinavian languages, Dutch, Polish, Czech, Serbo-Croatian, Macedonian, Slovak, Slovenian and Russian), whereas in other languages, like English (''gymnasium'', ''gym'') and Spanish (''gimnasio''), the former meaning of a place for physical education was retained. School structure Be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maastrichtian
The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interval from . The Maastrichtian was preceded by the Campanian and succeeded by the Danian (part of the Paleogene and Paleocene). The Cretaceous–Paleogene extinction event (formerly known as the Cretaceous–Tertiary extinction event) occurred at the end of this age. In this mass extinction, many commonly recognized groups such as non-avian dinosaurs, plesiosaurs and mosasaurs, as well as many other lesser-known groups, died out. The cause of the extinction is most commonly linked to an asteroid about wide colliding with Earth, ending the Cretaceous. Stratigraphic definitions Definition The Maastrichtian was introduced into scientific literature by Belgian geologist André Hubert Dumont in 1849, after studying rock strata of the Chalk Group c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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