William R. Hammer
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William R. Hammer
William Roy Hammer is an American paleontologist who is credited with the discovery of the first carnivorous dinosaur unearthed in Antarctica, Cryolophosaurus, in 1991. He was professor of geology and curator of the Frxyell Geology Museum at Augustana College in Rock Island, IL from 1981 to 2017. Biography Hammer was born in Detroit, Michigan and attended Wayne State University where he earned a bachelor's degree and masters in Zoology and completed a doctorate in Paleontology. As a student researcher, he was introduced to the study of fossil vertebrates in Antarctica by his advisor, Dr. John Cosgriff. Contributions to paleontology Hammer was part of eight expeditions to Antarctica between 1977 and 2017. In 1991, Ohio State University geologist David Elliot was studying igneous rocks on Mt. Kirkpatrick near the Beardmore Glacier in Antarctica when he found some scree that contained bone. Hammer, who was working on synapsids fossils nearby, investigated the site and found t ...
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Detroit
Detroit ( , ; , ) is the largest city in the U.S. state of Michigan. It is also the largest U.S. city on the United States–Canada border, and the seat of government of Wayne County. The City of Detroit had a population of 639,111 at the 2020 census, making it the 27th-most populous city in the United States. The metropolitan area, known as Metro Detroit, is home to 4.3 million people, making it the second-largest in the Midwest after the Chicago metropolitan area, and the 14th-largest in the United States. Regarded as a major cultural center, Detroit is known for its contributions to music, art, architecture and design, in addition to its historical automotive background. ''Time'' named Detroit as one of the fifty World's Greatest Places of 2022 to explore. Detroit is a major port on the Detroit River, one of the four major straits that connect the Great Lakes system to the Saint Lawrence Seaway. The City of Detroit anchors the second-largest regional economy in t ...
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Rock Island, Illinois
Rock Island is a city in and the county seat of Rock Island County, Illinois, Rock Island County, Illinois, United States. The original Rock Island, from which the city name is derived, is now called Rock Island Arsenal, Arsenal Island. The population was 37,108 at the United States Census 2020, 2020 census. Located on the Mississippi River, it is one of the Quad Cities, along with neighboring Moline, Illinois, Moline, East Moline, Illinois, East Moline, and the Iowa cities of Davenport, Iowa, Davenport and Bettendorf, Iowa, Bettendorf. The Quad Cities has a population of about 380,000. The city is home to Rock Island Arsenal, the largest government-owned weapons manufacturing arsenal in the US, which employs 6,000 people. Rock Island School District, The Rock Island–Milan School District, Rockridge School District (southwest portion of city) along with private schools, serve the city. The District (Downtown Rock Island) has art galleries and theaters, nightclubs and coffee shop ...
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Year Of Birth Missing (living People)
A year or annus is the orbital period of a planetary body, for example, the Earth, moving in its orbit around the Sun. Due to the Earth's axial tilt, the course of a year sees the passing of the seasons, marked by change in weather, the hours of daylight, and, consequently, vegetation and soil fertility. In temperate and subpolar regions around the planet, four seasons are generally recognized: spring, summer, autumn and winter. In tropical and subtropical regions, several geographical sectors do not present defined seasons; but in the seasonal tropics, the annual wet and dry seasons are recognized and tracked. A calendar year is an approximation of the number of days of the Earth's orbital period, as counted in a given calendar. The Gregorian calendar, or modern calendar, presents its calendar year to be either a common year of 365 days or a leap year of 366 days, as do the Julian calendars. For the Gregorian calendar, the average length of the calendar year (the ...
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Glacialisaurus
''Glacialisaurus'' is a genus of sauropodomorph dinosaur. It lived during the Pliensbachian stage of the Early Jurassic period around 186 to 182 million years ago in what is now the central region of the Transantarctic Mountains of Antarctica. It is known from two specimens; the holotype (name-bearing specimen), a partial tarsus (ankle) and metatarsus, and a partial left femur. The fossils were collected by a team led by paleontologist William R. Hammer during a 1990–91 field expedition to the Hanson Formation of Antarctica. They were described in 2007, and made the basis of the new genus and species ''Glacialisaurus hammeri''. The genus name translates as “icy” or "frozen lizard”, and the species name honors Hammer. This dinosaur has been classified as a massospondylid, a group of medium-sized, basal (early diverging or "primitive") sauropodomorphs that existed during the Late Triassic and Early Jurassic on every continent except Australia. Its length has been estim ...
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Sauropodomorpha
Sauropodomorpha ( ; from Greek, meaning "lizard-footed forms") is an extinct clade of long-necked, herbivorous, saurischian dinosaurs that includes the sauropods and their ancestral relatives. Sauropods generally grew to very large sizes, had long necks and tails, were quadrupedal, and became the largest animals to ever walk the Earth. The '' prosauropods,'' which preceded the sauropods, were smaller and were often able to walk on two legs. The sauropodomorphs were the dominant terrestrial herbivores throughout much of the Mesozoic Era, from their origins in the Late Triassic (approximately 230 Ma) until their decline and extinction at the end of the Cretaceous. Description Sauropodomorphs were adapted to browsing higher than any other contemporary herbivore, giving them access to high tree foliage. This feeding strategy is supported by many of their defining characteristics, such as: a light, tiny skull on the end of a long neck (with ten or more elongated cervical vertebrae) ...
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Dinosaur
Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is the subject of active research. They became the dominant terrestrial vertebrates after the Triassic–Jurassic extinction event 201.3 mya; their dominance continued throughout the Jurassic and Cretaceous periods. The fossil record shows that birds are feathered dinosaurs, having evolved from earlier theropods during the Late Jurassic epoch, and are the only dinosaur lineage known to have survived the Cretaceous–Paleogene extinction event approximately 66 mya. Dinosaurs can therefore be divided into avian dinosaurs—birds—and the extinct non-avian dinosaurs, which are all dinosaurs other than birds. Dinosaurs are varied from taxonomic, morphological and ecological standpoints. Birds, at over 10,700 living species, are among ...
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Femur
The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with the tibia (shinbone) and patella (kneecap), forming the knee joint. By most measures the two (left and right) femurs are the strongest bones of the body, and in humans, the largest and thickest. Structure The femur is the only bone in the upper leg. The two femurs converge medially toward the knees, where they articulate with the proximal ends of the tibiae. The angle of convergence of the femora is a major factor in determining the femoral-tibial angle. Human females have thicker pelvic bones, causing their femora to converge more than in males. In the condition ''genu valgum'' (knock knee) the femurs converge so much that the knees touch one another. The opposite extreme is ''genu varum'' (bow-leggedness). In the general populatio ...
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Synapsid
Synapsids + (, 'arch') > () "having a fused arch"; synonymous with ''theropsids'' (Greek, "beast-face") are one of the two major groups of animals that evolved from basal amniotes, the other being the sauropsids, the group that includes reptiles and birds. The group includes mammals and every animal more closely related to mammals than to sauropsids. Unlike other amniotes, synapsids have a single temporal fenestra, an opening low in the skull roof behind each eye orbit, leaving a bony arch beneath each; this accounts for their name. The distinctive temporal fenestra developed about 318 million years ago during the Late Carboniferous period, when synapsids and sauropsids diverged, but was subsequently merged with the orbit in early mammals. Traditionally, non-mammalian synapsids were believed to have evolved from reptiles, and therefore described as mammal-like reptiles in classical systematics, and primitive synapsids were also referred to as pelycosaurs, or pelycosaur-gr ...
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Scree
Scree is a collection of broken rock fragments at the base of a cliff or other steep rocky mass that has accumulated through periodic rockfall. Landforms associated with these materials are often called talus deposits. Talus deposits typically have a concave upwards form, where the maximum inclination corresponds to the angle of repose of the mean debris particle size. The exact definition of scree in the primary literature is somewhat relaxed, and it often overlaps with both ''talus'' and ''colluvium''. The term ''scree'' comes from the Old Norse term for landslide, ''skriða'', while the term ''talus'' is a French word meaning a slope or embankment. In high-altitude arctic and subarctic regions, scree slopes and talus deposits are typically adjacent to hills and river valleys. These steep slopes usually originate from late-Pleistocene periglacial processes. Notable scree sites in Eastern North America include the Ice Caves at White Rocks National Recreation Area in southern Ve ...
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Beardmore Glacier
The Beardmore Glacier in Antarctica is one of the largest valley glaciers in the world, being long and having a width of . It descends about from the Antarctic Plateau to the Ross Ice Shelf and is bordered by the Commonwealth Range of the Queen Maud Mountains on the eastern side and the Queen Alexandra Range of the Central Transantarctic Mountains on the western. The glacier is one of the main passages through the Transantarctic Mountains to the great polar plateau beyond, and was one of the early routes to the South Pole despite its steep upward incline. The glacier was discovered and climbed by Ernest Shackleton during his ''Nimrod'' Expedition of 1908. Although Shackleton turned back at latitude 88° 23' S, just from the South Pole, he established the first proven route towards the pole and, in doing so, became the first person to set foot upon the polar plateau. In 1911–1912, Captain Scott and his ''Terra Nova'' Expedition team reached the South Pole by simi ...
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Igneous Rock
Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main The three types of rocks, rock types, the others being Sedimentary rock, sedimentary and metamorphic rock, metamorphic. Igneous rock is formed through the cooling and solidification of magma or lava. The magma can be derived from Partial melting, partial melts of existing rocks in either a Terrestrial planet, planet's mantle (geology), mantle or crust (geology), crust. Typically, the melting is caused by one or more of three processes: an increase in temperature, a decrease in pressure, or a change in composition. Solidification into rock occurs either below the surface as intrusive rocks or on the surface as extrusive (geology), extrusive rocks. Igneous rock may form with crystallization to form granular, crystalline rocks, or without crystallization to form Volcanic glass, natural glasses. Igneous rocks occur in a wide range of geological settings: shields, platforms ...
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Geologist
A geologist is a scientist who studies the solid, liquid, and gaseous matter that constitutes Earth and other terrestrial planets, as well as the processes that shape them. Geologists usually study geology, earth science, or geophysics, although backgrounds in physics, chemistry, biology, and other sciences are also useful. Field research (field work) is an important component of geology, although many subdisciplines incorporate laboratory and digitalized work. Geologists can be classified in a larger group of scientists, called geoscientists. Geologists work in the energy and mining sectors searching for natural resources such as petroleum, natural gas, precious and base metals. They are also in the forefront of preventing and mitigating damage from natural hazards and disasters such as earthquakes, volcanoes, tsunamis and landslides. Their studies are used to warn the general public of the occurrence of these events. Geologists are also important contributors to climate ch ...
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