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Prolagus Sardus
The Sardinian pika (''Prolagus sardus'') is an extinct species of lagomorph that was endemic to the islands of Sardinia, Corsica and neighbouring Mediterranean islands until its extinction likely in Roman times. It was the last surviving member of ''Prolagus,'' a genus of lagomorph with a fossil record spanning 20 million years once widespread throughout Europe during the Miocene and Pliocene epochs. Its closest living relatives are modern pikas (which all belong to the genus '' Ochotona''), from which it is estimated to have diverged around 30 million years ago. Anatomy The full skeletal structure of the Sardinian pika was reconstructed in 1967, thanks to the numerous finds of bones in Corbeddu Cave, which is near Oliena, Sardinia. Some years later, from these remains, the same researchers led by paleontologist Mary R. Dawson from the US were able to create a plaster reconstruction with good accuracy, and provide a thorough description of the skeleton's morphology published in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Pleistocene
The Chibanian, more widely known as the Middle Pleistocene (its previous informal name), is an Age (geology), age in the international geologic timescale or a Stage (stratigraphy), 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 0.7741 annum, Ma (774,100 years ago) and 0.129 Ma (129,000 years ago), also expressed as 774.1–129 ka. It includes the transition in palaeoanthropology from the Lower Paleolithic, Lower to the Middle Paleolithic over 300 ka. The Chibanian is preceded by the Calabrian (stage), Calabrian and succeeded by the Late Pleistocene. The beginning of the Chibanian is the Brunhes–Matuyama reversal, when the Earth's magnetic field last underwent reversal. Its end roughly coincides with the termination of the Penultimate Glacial Period and the onset of the Last Interglacial period (correspondin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypsodont
Hypsodont is a pattern of dentition characterized by with high crowns, providing extra material for wear and tear. Some examples of animals with hypsodont dentition are cows and horses; all animals that feed on gritty, fibrous material. The opposite condition is called brachydont. Evolution Since the morphology of the hypsodont tooth is suited to a more abrasive diet, hypsodonty was thought to have evolved concurrently with the spread of grasslands. Grass contains phytoliths, silica-rich granules, which wear away dental tissue more quickly. Analysis has shown, however, that the development of this morphology is out of sync with the spread and flourishing of grasslands. Instead, the ingestion of grit and soil is hypothesized to be the primary driver of hypsodonty, a hypothesis termed the grit, not grass hypothesis. Morphology Hypsodont dentition is characterized by: * high-crowned teeth * A rough, flattish occlusal surface adapted for crushing and grinding * Cementum both ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pika
A pika ( , or ) is a small, mountain-dwelling mammal native to Asia and North America. With short limbs, a very round body, an even coat of fur, and no external tail, they resemble their close relative the rabbit, but with short, rounded ears. The large-eared pika of the Himalayas and nearby mountains lives at elevations of more than . The name ''pika'' appears to be derived from the Tungus ''pika'', and the scientific name ''Ochotona'' is derived from the Mongolian word ''ogotno, оготно'', which means pika. It is used for any member of the Ochotonidae (), a family within the order of lagomorphs, the order which also includes the Leporidae (rabbits and hares). They are the smallest animal in the lagomorph group. Only one genus, ''Ochotona'' ( or ), is extant within the family, covering 37 species, though many fossil genera are known. Another species, the Sardinian pika, belonging to the separate genus '' Prolagus'', has become extinct within the last 2,000 years owi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bubo (genus)
The American (North and South America) horned owls and the Old World eagle-owls make up the genus ''Bubo'', at least as traditionally described. The genus name ''Bubo'' is Latin for owl. This genus contains 10 species that are found in many parts of the world. Some of the largest living Strigiformes are in ''Bubo''. Traditionally, only owls with ear-tufts were included in this genus, but that is no longer the case. Taxonomy The genus ''Bubo'' was introduced in 1805 by the French zoologist André Duméril for the horned owls. The type species is the Eurasian eagle-owl. The word ''bubo'' is Latin for the Eurasian eagle owl and was used as the specific epithet for the species by Carl Linnaeus in 1758. A molecular phylogenetic study published in 2020 found that species in the genera ''Scotopelia'' and ''Ketupa'' were embedded within the clade containing members of the genus ''Bubo'' making the genus ''Bubo'' paraphyletic. To create monophyletic genera, nine species were move ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enhydrictis
''Enhydrictis'' is a genus of extinct mustelid, belonging to the subfamily Galictinae. The type species, and best known, is ''Enhydrictis galictoides'' from the Pleistocene of Sardinia and Corsica. Some authors attribute species from mainland Eurasia to the genus, but this is disputed, with others considering the genus endemic to Sardinia-Corsica. Taxonomy The exact number of species of ''Enhydrictis'' has been a matter of debate. One species of '' Pannonictis'', ''Pannonictis pilgrimi'', has been classified as a belonging to ''Enhydrictis'' (as ''Enhydrictis ardea''), although this is unlikely. A 2019 study also suggests that the genus '' Oriensictis'' of Asia should be considered a synonym of ''Enhydrictis'' as well. In 2016, a new species from Algeria was described. Known as ''Enhydrictis hoffstetteri'', it is the first member of the genus known from Africa. Other scholars have considered the attribution of this species to ''Enhydrictis'' doubtful, and that the species should b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mustelidae
The Mustelidae (; from Latin , weasel) are a diverse family of carnivora, carnivoran mammals, including weasels, badgers, otters, polecats, martens, grisons, and wolverines. Otherwise known as mustelids (), they form the largest family in the suborder Caniformia of the order (biology), order Carnivora with about 66 to 70 species in nine subfamilies. Variety Mustelids vary greatly in size and behaviour. The smaller variants of the least weasel can be under in length, while the giant otter of Amazon rainforest, Amazonian South America can measure up to and sea otters can exceed in weight. Wolverines can crush bones as thick as the femur of a moose to get at the Bone marrow, marrow, and have been seen attempting to drive bears away from their kills. The sea otter uses rocks to break open shellfish to eat. Martens are largely arboreal, while European badgers dig extensive tunnel networks, called setts. Only one mustelid has been domesticated; the ferret. Tayra are also kept ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sardinian Dhole
The Sardinian dhole (genus ''Cynotherium'' especially ''C. sardous'') is an extinct insular canid which was endemic to what is now the Mediterranean islands of Sardinia and Corsica during the Middle-Late Pleistocene. It went extinct at the end of the Pleistocene around the time of human settlement of the islands. Its scientific name means "dog-beast of Sardinia", the genus name from the and and the specific name from the , alt. form of . Around the size of a jackal, morphological studies indicate it was a specialised stalking predator of small mammals and birds, with a probable preference for the endemic Sardinian pika. Evolution The oldest remains of ''Cynotherium'' on Sardinia date to around the early-Middle Pleistocene transition around 800,000 years ago, associated with a faunal turnover event on Sardinia likely caused low sea levels allowing dispersal to Sardinia-Corsica from mainland Italy. ''Cynotherium'' is suggested to have originated from the species '' Xenocyon l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skeletochronology
Skeletochronology is a technique used to determine the individual, chronological ages of vertebrates by counting lines of arrested, annual growth, also known as LAGs, within skeletal tissues. Within the annual bone growth specimens, there are broad and narrow lines. Broad lines represent the growth period and narrow lines represent a growth pause. These narrow lines are what characterises one growth year, therefore make it suitable to determine the age of the specimen. Not all bones grow at the same rate and the individual growth rate of a bone changes over a lifetime, therefore periodic growth marks can take irregular patterns. This indicates significant chronological events in an individual's life. The use of bone as a biomaterial is useful in investigating structure-property relationships. In addition to current research in skeletochronology, the ability of bone to adapt and change its structure to the external environment provides potential for further research in bone histom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthritis
Arthritis is a general medical term used to describe a disorder that affects joints. Symptoms generally include joint pain and stiffness. Other symptoms may include redness, warmth, Joint effusion, swelling, and decreased range of motion of the affected joints. In certain types of arthritis, other organs such as the skin are also affected. Onset can be gradual or sudden. There are several types of arthritis. The most common forms are osteoarthritis (most commonly seen in weightbearing joints) and rheumatoid arthritis. Osteoarthritis usually occurs as an individual ages and often affects the hips, knees, shoulders, and fingers. Rheumatoid arthritis is an autoimmune disorder that often affects the hands and feet. Other types of arthritis include gout, lupus, and septic arthritis. These are inflammatory based types of rheumatic disease. Early treatment for arthritis commonly includes resting the affected joint and conservative measures such as heating or icing. Weight Weight ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Population Density
Population density (in agriculture: Standing stock (other), standing stock or plant density) is a measurement of population per unit land area. It is mostly applied to humans, but sometimes to other living organisms too. It is a key geographical term.Matt RosenberPopulation Density Geography.about.com. March 2, 2011. Retrieved on December 10, 2011. Biological population densities Population density is population divided by total land area, sometimes including seas and oceans, as appropriate. Low densities may cause an extinction vortex and further reduce fertility. This is called the Allee effect after the scientist who identified it. Examples of the causes of reduced fertility in low population densities are: * Increased problems with locating sexual mates * Increased inbreeding Human densities Population density is the number of people per unit of area, usually transcribed as "per square kilometre" or square mile, and which may include or exclude, for example, ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bone Bed
A bone bed is any Geology, geological stratum or deposition (geology), deposit that contains bones of whatever kind. Inevitably, such deposits are Sedimentary rock, sedimentary in nature. Not a formal term, it tends to be used more to describe especially dense collections such as Lagerstätte. It is also applied to brecciated and Stalagmite, stalagmitic deposits on the floor of caves, which frequently contain osseous remains. In a more restricted sense, the term is used to describe certain thin layers of bony fragments, which occur in well-defined geological strata. One of the best-known of these is the Ludlow Bone Bed, which is found at the base of the Downton Sandstone in the Ludlow Group, Upper Ludlow series. At Ludlow (England) itself, two such beds are actually known, separated by about . of strata. Although quite thin, the Ludlow Bone Bed can be followed from that town into Gloucestershire, for a distance of . It is almost completely made up of fragments of Spine (zoology), s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Habitat
In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ecological niche. Thus "habitat" is a species-specific term, fundamentally different from concepts such as Biophysical environment, environment or vegetation assemblages, for which the term "habitat-type" is more appropriate. The physical factors may include (for example): soil, moisture, range of temperature, and Luminous intensity, light intensity. Biotic index, Biotic factors include the availability of food and the presence or absence of Predation, predators. Every species has particular habitat requirements, habitat generalist species are able to thrive in a wide array of environmental conditions while habitat specialist species require a very limited set of factors to survive. The habitat of a species is not necessarily found in a ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
