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Megalocnus Rodens
''Megalocnus'' ("great sloth" in Greek) is a genus of extinct large ground sloths that were native to Cuba during the Pleistocene and Holocene epochs. They were among the largest of the Caribbean sloths (Megalocnidae), with individuals estimated to have weighed up to 270 kg (595 lbs) to 200 kg (440 lbs), around the size of a American black bear, black bear when alive.Steadman, D. W., Martin, P. S., MacPhee, R. D., Jull, A. T., McDonald, H. G., Woods, C. A., ... & Hodgins, G. W. (2005). Asynchronous extinction of late Quaternary sloths on continents and islands. ''Proceedings of the National Academy of Sciences'', ''102''(33), 11763-11768. Its relatives include other megalocnid sloths, such as ''Acratocnus'', ''Mesocnus'', ''Miocnus'', ''Neocnus and'' ''Parocnus''. The former species ''M. zile'' from Hispaniola is currently thought to be a junior synonym of ''Parocnus serus''. Etymology ''Megalocnus'', the generic name, means "great sloth" after the similarities between the holot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megalocnidae
Megalocnidae is an extinct family of sloths, native to the islands of the Greater Antilles from the Early Oligocene to the Mid-Holocene. They are known from Cuba, Hispaniola and Puerto Rico, but are absent from Jamaica. While they were formerly placed in the Megalonychidae alongside two-toed sloths and ground sloths like ''Megalonyx'', recent mitochondrial DNA and collagen sequencing studies place them as the earliest diverging group basal to all other sloths. They displayed significant diversity in body size and lifestyle, with '' Megalocnus'' being terrestrial and probably weighing several hundred kilograms, while '' Neocnus'' was likely arboreal and similar in weight to extant tree sloths, at less than 10 kilograms. Origin It is thought that sloths arrived in the Caribbean from South America (where they arose) around the Eocene-Oligocene boundary about 33 million years ago, when there was a significant sea level drop caused by a glaciation episode. This has been assoc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kiloannum
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 mean yea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Puerto Rico At Mayagüez
The University of Puerto Rico, Mayagüez Campus (UPRM) or Recinto Universitario de Mayagüez (RUM) in Spanish (also referred to as Colegio and CAAM in allusion to its former name), is a public land-grant university in Mayagüez, Puerto Rico. UPRM is the second-largest university campus of the University of Puerto Rico system. In addition to its status as a land-grant university, it is also a member of the sea-grant and space-grant research consortia. In 2009, the campus population was composed of 12,108 students, 1,924 regular staff members, and 1,037 members of the education staff. In 2013, the student population remained relatively steady at 11,838, but the instructional faculty dropped to 684. In the second semester of 2019 around 12,166 students where enrolled. UPRM has been accredited by the Middle States Commission on Higher Education (MSCHE) since 1946. History The University of Puerto Rico was created by an act of the Legislative Assembly on March 12, 1903, emerging as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caribbean Journal Of Science
The ''Caribbean Journal of Science'' is a triannual peer-reviewed open-access scientific journal publishing articles, research notes, and book reviews related to science in the Caribbean, with an emphasis on botany, zoology, ecology, conservation biology, geology, archaeology, and paleontology. The journal was established in 1961 with the sponsorship of the College of Arts and Sciences of the University of Puerto Rico at Mayagüez. Abstracting and indexing The journal is abstracted and indexed in Biological Abstracts, BIOSIS Previews, Current Contents/Agriculture, Biology & Environmental Sciences, Science Citation Index Expanded, Scopus, and The Zoological Record. According to the ''Journal Citation Reports'', the journal has a 2016 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Before Present
Before Present (BP) years, or "years before present", is a time scale used mainly in archaeology, geology and other scientific disciplines to specify when events occurred relative to the origin of practical radiocarbon dating in the 1950s. Because the "present" time changes, standard practice is to use 1 January 1950 as the commencement date (epoch) of the age scale. The abbreviation "BP" has been interpreted retrospectively as "Before Physics", which refers to the time before nuclear weapons testing artificially altered the proportion of the carbon isotopes in the atmosphere, which scientists must now account for. In a convention that is not always observed, many sources restrict the use of BP dates to those produced with radiocarbon dating; the alternative notation RCYBP stands for the explicit "radio carbon years before present". Usage The BP scale is sometimes used for dates established by means other than radiocarbon dating, such as stratigraphy. This usage differs from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiocarbon Dating
Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon. The method was developed in the late 1940s at the University of Chicago by Willard Libby. It is based on the fact that radiocarbon () is constantly being created in the Earth's atmosphere by the interaction of cosmic rays with atmospheric nitrogen. The resulting combines with atmospheric oxygen to form radioactive carbon dioxide, which is incorporated into plants by photosynthesis; animals then acquire by eating the plants. When the animal or plant dies, it stops exchanging carbon with its environment, and thereafter the amount of it contains begins to decrease as the undergoes radioactive decay. Measuring the amount of in a sample from a dead plant or animal, such as a piece of wood or a fragment of bone, provides information that can be used to ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Accelerator Mass Spectrometry
Accelerator mass spectrometry (AMS) is a form of mass spectrometry that accelerates ions to extraordinarily high kinetic energies before mass analysis. The special strength of AMS among the mass spectrometric methods is its power to separate a rare isotope from an abundant neighboring mass ("abundance sensitivity", e.g. 14C from 12C). The method suppresses molecular isobars completely and in many cases can separate atomic isobars (e.g. 14N from 14C) also. This makes possible the detection of naturally occurring, long-lived radio-isotopes such as 10Be, 36Cl, 26Al and 14C. Their typical isotopic abundance ranges from 10−12 to 10−18. AMS can outperform the competing technique of decay counting for all isotopes where the half-life is long enough. Other advantages of AMS include its short measuring time as well as its ability to detect atoms in extremely small samples. The method Generally, negative ions are created (atoms are ionized) in an ion source. In for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subfossil
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 ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haiti
Haiti (; ht, Ayiti ; French: ), officially the Republic of Haiti (); ) and formerly known as Hayti, is a country located on the island of Hispaniola in the Greater Antilles archipelago of the Caribbean Sea, east of Cuba and Jamaica, and south of The Bahamas and the Turks and Caicos Islands. It occupies the western three-eighths of the island which it shares with the Dominican Republic. To its south-west lies the small Navassa Island, which is claimed by Haiti but is disputed as a United States territory under federal administration."Haiti" ''Encyclopædia Britannica''. Haiti is in size, the third largest country in the by area, and has an estimated population of 11.4 million, making it the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tortuga (Haiti)
Tortuga Island (french: Île de la Tortue, ; ht, Latòti; es, Isla Tortuga, , ''Turtle Island'') is a Caribbean island that forms part of Haiti, off the northwest coast of Hispaniola. It constitutes the ''commune'' of Île de la Tortue in the Port-de-Paix arrondissement of the Nord-Ouest department of Haiti. Tortuga is in size and had a population of 25,936 at the 2003 Census. In the 17th century, Tortuga was a major center and haven of Caribbean piracy. Its tourist industry and references in many works have made it one of the most recognized regions of Haiti. History The first Europeans to land on Tortuga were the Spanish in 1492 during the first voyage of Christopher Columbus into the New World. On December 6, 1492, three Spanish ships entered the Windward Passage that separates Cuba and Haiti. At sunrise, Columbus noticed an island whose contours emerged from the morning mist. Because the shape reminded him of a turtle's shell, he chose the name of Tortuga. Tortuga w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Puerto Rico
Puerto Rico (; abbreviated PR; tnq, Boriken, ''Borinquen''), officially the Commonwealth of Puerto Rico ( es, link=yes, Estado Libre Asociado de Puerto Rico, lit=Free Associated State of Puerto Rico), is a Caribbean island and unincorporated territory of the United States. It is located in the northeast Caribbean Sea, approximately southeast of Miami, Florida, between the Dominican Republic and the U.S. Virgin Islands, and includes the eponymous main island and several smaller islands, such as Mona, Culebra, and Vieques. It has roughly 3.2 million residents, and its capital and most populous city is San Juan. Spanish and English are the official languages of the executive branch of government, though Spanish predominates. Puerto Rico was settled by a succession of indigenous peoples beginning 2,000 to 4,000 years ago; these included the Ortoiroid, Saladoid, and Taíno. It was then colonized by Spain following the arrival of Christopher Columbus in 1493. Puerto Ri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
