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Maelestes
''Maelestes'' is a prehistoric shrew-like mammal discovered in 1997 in the Gobi Desert. The animal lived in the late Cretaceous Period, around 71-75 million years ago, and was a contemporary of dinosaurs such as '' Velociraptor'' and '' Oviraptor''. According to some scientists, the discovery and analysis of this species suggests that true placental mammals appeared near the time the non-avian dinosaurs became extinct 66 million years ago, not much earlier in the Cretaceous as thought by others.Wible, J.R., G.W. Rougier, M.J. Novacek, and R.J. Asher. (2007). "Cretaceous eutherians and Laurasian origin for placental mammals near the K/T boundary." ''Nature'', 447: 1003-1006. However, the presence of an epipubic bone, among other characteristics, place it as a non-placental eutherian.Giallombardo, Andres, 2009 New Cretaceous mammals from Mongolia and the early diversification of Eutheria Ph.D. dissertation, Columbia University, 2009402 pages; AAT 3373736 (abstract) The origin o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Australia a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oviraptor
''Oviraptor'' (; ) is a genus of oviraptorid dinosaur that lived in Asia during the Late Cretaceous period. The first remains were collected from the Djadokhta Formation of Mongolia in 1923 during a paleontological expedition led by Roy Chapman Andrews, and in the following year the genus and type species ''Oviraptor philoceratops'' were named by Henry Fairfield Osborn. The genus name refers to the initial thought of egg-stealing habits, and the specific name was intended to reinforce this view indicating a preference over ceratopsian eggs. Despite the fact that numerous specimens have been referred to the genus, ''Oviraptor'' is only known from a single partial skeleton regarded as the holotype, as well as a nest of about fifteen eggs and several small fragments from a juvenile. ''Oviraptor'' was a rather small feathered oviraptorid, estimated at long with a weight between . It had a wide lower jaw with a skull that likely had a crest. Both upper and lower jaws were toothle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous Mammals Of Asia
Late may refer to: * LATE, an acronym which could stand for: ** Limbic-predominant age-related TDP-43 encephalopathy, a proposed form of dementia ** Local-authority trading enterprise, a New Zealand business law ** Local average treatment effect, a concept in econometrics Music * ''Late'' (album), a 2000 album by The 77s * Late!, a pseudonym used by Dave Grohl on his ''Pocketwatch'' album * Late (rapper), an underground rapper from Wolverhampton * "Late" (song), a song by Blue Angel * "Late", a song by Kanye West from ''Late Registration'' Other * Late (Tonga), an uninhabited volcanic island southwest of Vavau in the kingdom of Tonga * "Late" (''The Handmaid's Tale''), a television episode * LaTe, Oy Laivateollisuus Ab, a defunct shipbuilding company * Late may refer to a person who is Dead See also * * * ''Lates'', a genus of fish in the lates perch family * Later (other) * Tardiness Tardiness is the habit of being late or delaying arrival. Being late as a fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous Mammals
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of the entire Phanerozoic. The name is derived from the Latin ''creta'', "chalk", which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation ''Kreide''. The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now- extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was ice free, and forests extended to the poles. During this time, new groups of mammals and birds appeared. During the Early Cretaceous, flowering plants appeared and began to rapidly diversify, becoming the dominant group of plants across the Earth by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carnegie Museum Of Natural History
The Carnegie Museum of Natural History (abbreviated as CMNH) is a natural history museum in the Oakland neighborhood of Pittsburgh, Pennsylvania. It was founded by Pittsburgh-based industrialist Andrew Carnegie in 1896. Housing some 22 million specimens, the museum features one of the finest paleontological collections in the world. Description and history The museum consists of organized into 20 galleries as well as research, library, and office space. It holds some 22 million specimens, of which about 10,000 are on view at any given time and about 1 million are cataloged in online databases. In 2008 it hosted 386,300 admissions and 63,000 school group visits. Museum education staff also actively engage in outreach by traveling to schools all around western Pennsylvania. The museum gained prominence in 1899 when its scientists unearthed the fossils of '' Diplodocus carnegii''. Notable dinosaur specimens include one of the world's very few fossils of a juvenile ''Apatosauru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shrew Opossum
The family Caenolestidae contains the seven surviving species of shrew opossum: small, shrew-like marsupials that are confined to the Andes mountains of South America. The order is thought to have diverged from the ancestral marsupial line very early. They were once included in the superorder but it is now known that Ameridelphia is paraphyletic, having given rise to Australidelphia, and thus could be considered an evolutionary grade. Genetic studies indicate that they are the second most basal order of marsupials, after the didelphimorphs. As recently as 20 million years ago, at least seven genera were in South America. Today, just three genera remain. They live in inaccessible forest and grassland regions of the High Andes. Shrews were entirely absent from South America until the Great American Interchange three million years ago, and are currently present only in the northwestern part of the continent. Traditionally, it was thought that shrew opossums lost ground to these and o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marsupials
Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia, Wallacea and the Americas. A distinctive characteristic common to most of these species is that the young are carried in a pouch. Marsupials include opossums, Tasmanian devils, kangaroos, koalas, wombats, wallabies, bandicoots, and the extinct thylacine. Marsupials represent the clade originating from the last common ancestor of extant metatherians, the group containing all mammals more closely related to marsupials than to placentals. They give birth to relatively undeveloped young that often reside in a pouch located on their mothers' abdomen for a certain amount of time. Close to 70% of the 334 extant species occur on the Australian continent (the mainland, Tasmania, New Guinea and nearby islands). The remaining 30% are found in the Americas—primarily in South America, thirteen in Central America, and one species, the Virginia opossum, in North Am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epipubic Bone
Epipubic bones are a pair of bones projecting forward from the pelvic bones of modern marsupials, monotremes and fossil mammals like multituberculates, and even basal eutherians (the ancestors of placental mammals, who lack them). They first occur in non-mammalian cynodonts such as tritylodontids, suggesting that they are a synapomorphy between them and Mammaliformes. They were first described as early as 1698, but to date, their function(s) remain unresolved. Epipubic bones are often called ''marsupial bones'' because they support the mother's pouch in modern marsupials ("''marsupium''" is Latin for "pouch"). Function Some writers have suggested that the epipubic bones are a part of a kinetic link stretching from the femur on one side, to the ribs on the opposite side. This linkage is formed by a series of muscles: Each epipubic bone is connected to the femur by the pectineus muscle, and to the ribs and vertebrae by the pyramidalis, rectus abdominis, and external and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Placental Mammal
Placental mammals ( infraclass Placentalia ) are one of the three extant subdivisions of the class Mammalia, the other two being Monotremata and Marsupialia. Placentalia contains the vast majority of extant mammals, which are partly distinguished from monotremes and marsupials in that the fetus is carried in the uterus of its mother to a relatively late stage of development. The name is something of a misnomer considering that marsupials also nourish their fetuses via a placenta, though for a relatively briefer period, giving birth to less developed young which are then nurtured for a period inside the mother's pouch. Anatomical features Placental mammals are anatomically distinguished from other mammals by: * a sufficiently wide opening at the bottom of the pelvis to allow the birth of a large baby relative to the size of the mother. * the absence of epipubic bones extending forward from the pelvis, which are found in all other mammals. (Their function in non-placental mammal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Velociraptor
''Velociraptor'' (; ) is a genus of small dromaeosaurid dinosaur that lived in Asia during the Late Cretaceous epoch, about 75 million to 71 million years ago. Two species are currently recognized, although others have been assigned in the past. The type species is ''V. mongoliensis''; fossils of this species have been discovered in the Djadochta Formation, Mongolia. A second species, ''V. osmolskae'', was named in 2008 for skull material from the Bayan Mandahu Formation, China. Smaller than other dromaeosaurids like '' Deinonychus'' and '' Achillobator'', ''Velociraptor'' was about long with a body mass between . It nevertheless shared many of the same anatomical features. It was a bipedal, feathered carnivore with a long tail and an enlarged sickle-shaped claw on each hindfoot, which is thought to have been used to tackle and restrain prey. ''Velociraptor'' can be distinguished from other dromaeosaurids by its long and low skull, with an upturned snout. ''Velociraptor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animalia
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of cells, the blastula, during embryonic development. Over 1.5 million living animal species have been described—of which around 1 million are insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology. Most living animal species are in Bilateria, a clade whose members have a Symmetry in biology#Bilateral symmetry, bilaterally symmetric body plan. The Bilateria include the protostomes, containing animals such as nematodes, arthropods, flatworms, annelids and molluscs, and th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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