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Dalanistes
''Dalanistes'' is an extinct genus of Remingtonocetidae, remingtonocetid Archaeoceti, early whale known from the late-early Eocene (Lutetian, ) of Kutch, India and Punjab, Pakistan, Punjab and Balochistan, Pakistan. ''Dalanistes'' is closely related to ''Remingtonocetus'' (the type genus of Remingtonocetidae, a slightly more derived family of early whales), but also shares several features with ''Ambulocetus'' (the type of Ambulocetidae, earlier more primitive whales), and, with its combination of terrestrial and amphibious adaptations, ''Dalanistes'' apparently is an intermediate form between these two groups. Isotopic evidence suggest that ''Dalanistes'' had a marine diet. ''Dalanistes'' is known from several localities and collections. The holotype is a skull and a postcranial skeleton. Additional fossils referred to ''Dalanistes'' include crania, several vertebrae and sacra, possible caudals, one side of the pelvis, and a distal femur. The Dental alveolus, alveoli is all tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Remingtonocetidae
Remingtonocetidae is a diverse family of early aquatic mammals of the order Cetacea. The family is named after paleocetologist Remington Kellogg. Description Remingtonocetids have long and narrow skulls with the external nare openings located on the front of the skull. Their frontal shields are narrow and their orbits small. Their mouth has a convex palate and an incompletely fused mandibular symphysis. The dental formula is . The anterior teeth are flattened mediolaterally, making them appear shark-like. In the postcranial skeleton, the cervical vertebrae are relatively long and the sacrum is composed of four vertebrae of which at least three are fused. The acetabular notch is narrow or closed and on the femoral head the fovea is absent. Cranial fossils are common but dental remains are rare. The postcrania morphology is based entirely on a single specimen of '' Kutchicetus'' which was small and had a long and muscular back and tail. Perhaps remintonocetids swam like ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeoceti
Archaeoceti ("ancient whales"), or Zeuglodontes in older literature, is an obsolete paraphyletic group of primitive cetaceans that lived from the Early Eocene to the late Oligocene (). Representing the earliest cetacean radiation, they include the initial amphibious stages in cetacean evolution, thus are the ancestors of both modern cetacean suborders, Mysticeti and Odontoceti. This initial diversification occurred in the shallow waters that separated India and Asia , resulting in some 30 species adapted to a fully oceanic life. Echolocation and filter-feeding evolved during a second radiation . All archaeocetes from the Ypresian (56–47.8 mya) and most from the Lutetian (47.8–41.3 mya) are known exclusively from Indo-Pakistan, but Bartonian (41.3–38.0 mya) and Priabonian (38.0–33.9 mya) genera are known from across Earth, including North America, Egypt, New Zealand, and Europe. Although no consensus exists regarding the mode of locomotion of which cetaceans were capabl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andrewsiphius
''Andrewsiphius'' is an extinct remingtonocetid early whale known from the Eocene (Lutetian, ) of Gujarat and Kutch, India and Balochistan, Pakistan. Discovery and naming The first specimen was collected by who described it as mandibular fragments of ''Protocetus sloani''. described two new species, ''Andrewsiphius kutchensis'' and ''A. minor'' based on their previous material and new mandibular fragments. Later researchers interpreted the same mandibular specimens as belonging to ''Remintonocetus''. reinterpreted these specimens as fragments from maxillae, and determined that the described "confluence of the mandibular canals anteriorly" was in fact the narial passages. Gingerich et al. also determined that the variations in size among proposed species were within the normal variation for a single species and therefore attributed a number of referred specimens as belonging to ''Andrewsiphius sloani''. Gingerich et al. also noted that the type specimen of '' Kutchicetus mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Remingtonocetus
''Remingtonocetus'' is an extinct genus of early cetacean freshwater aquatic mammals of the family (biology), family Remingtonocetidae endemic to the coastline of the ancient Tethys Ocean during the Eocene. It was named after naturalist Remington Kellogg. History of discovery named ''Protocetus harudiensis'' based on a partial skeleton, the type specimen found in the Lutetian shallow subtidal mudstone in the Harudi Formation, India. renamed it ''Remingtononocetus harudiensis'' due to morphological differences from ''Protocetus''. ''Remingtonocetus domandaensis'' was named by based on a partial skeleton found in a Lutetian coastal shale in the Domanda Formation of Pakistan. ''Remingtonocetus'' is larger, has a broader Rostrum (anatomy), rostrum, and longer premolars than ''Andrewsiphius''. It is smaller than, has more gracile premolars and molars than ''Dalanistes''. ''R. harudiensis'' differs from ''R. domandaensis'' in molar morphology. Description ''Remingtonocetus'' was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Michigan Museum Of Natural History
A university () is an institution of tertiary education and research which awards academic degrees in several academic disciplines. ''University'' is derived from the Latin phrase , which roughly means "community of teachers and scholars". Universities typically offer both undergraduate and postgraduate programs. The first universities in Europe were established by Catholic monks. The University of Bologna (), Italy, which was founded in 1088, is the first university in the sense of: *being a high degree-awarding institute. *using the word (which was coined at its foundation). *having independence from the ecclesiastic schools and issuing secular as well as non-secular degrees (with teaching conducted by both clergy and non-clergy): grammar, rhetoric, logic, theology, canon law and notarial law.Hunt Janin: "The university in medieval life, 1179–1499", McFarland, 2008, , p. 55f.de Ridder-Symoens, Hilde''A History of the University in Europe: Volume 1, Universities in the M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dental Alveolus
Dental alveoli (singular ''alveolus'') are sockets in the jaws in which the roots of teeth are held in the alveolar process with the periodontal ligament. The lay term for dental alveoli is tooth sockets. A joint that connects the roots of the teeth and the alveolus is called a ''gomphosis'' (plural ''gomphoses''). Alveolar bone is the bone that surrounds the roots of the teeth forming bone sockets. In mammals, tooth sockets are found in the maxilla, the premaxilla, and the mandible. Etymology 1706, "a hollow", especially "the socket of a tooth", from Latin alveolus "a tray, trough, basin; bed of a small river; small hollow or cavity", diminutive of alvus "belly, stomach, paunch, bowels; hold of a ship", from PIE root *aulo- "hole, cavity" (source also of Greek aulos "flute, tube, pipe"; Serbo-Croatian, Polish, Russian ulica "street", originally "narrow opening"; Old Church Slavonic uliji, Lithuanian aulys "beehive" (hollow trunk), Armenian yli "pregnant"). The word was extended ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extinct Animals Of Pakistan
Extinction is the termination of an organism by the death of its last member. A taxon may become functionally extinct before the death of its last member if it loses the capacity to reproduce and recover. As a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the fossil record) after a period of apparent absence. Over five billion species are estimated to have died out. It is estimated that there are currently around 8.7 million species of eukaryotes globally, possibly many times more if microorganisms are included. Notable extinct animal species include non-avian dinosaurs, saber-toothed cats, and mammoths. Through evolution, species arise through the process of speciation. Species become extinct when they are no longer able to survive in changing conditions or against superior ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene Mammals Of Asia
The Eocene ( ) is a geological epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period in the modern Cenozoic 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.See: *Letter from William Whewell to Charles Lyell dated 31 January 1831 in: * From p. 55: "The period next antecedent we shall call Eocene, from ήως, aurora, and χαινος, recens, because the extremely small proportion of living species contained in these strata, indicates what may be considered the first commencement, or ''dawn'', of the existing state of the animate creation." 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 13C in the atmosphere was exceptionally low in com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolution Of Cetaceans
The evolution of cetaceans is thought to have begun in the Indian subcontinent from even-toed ungulates (Artiodactyla) 50 million years ago (mya) and to have proceeded over a period of at least 15 million years. Cetaceans are fully aquatic mammals belonging to the order Artiodactyla and branched off from other artiodactyls around 50 Year#Abbreviations yr and ya, mya. Cetaceans are thought to have evolved during the Eocene (56-34 mya), the second epoch of the present-extending Cenozoic Era. Molecular and morphological analyses suggest Cetacea share a relatively recent closest common ancestor with hippopotamus, hippopotamuses and that they are sister groups. Being mammals, they surface to breathe air; they have five finger bones (even-toed) in their fins; they nurse their young; and, despite their fully aquatic life style, they retain many skeletal features from their terrestrial ancestors.Thewissen, J. G. M., L. N. Cooper, J. C. George, and S. Bajpai. 2009. From land to wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Asian River Dolphin
South Asian river dolphins are toothed whales in the genus ''Platanista'', which inhabit the waterways of the Indian subcontinent. They were historically considered to be one species (''P. gangetica'') with the Ganges river dolphin and the Indus river dolphin being subspecies (''P. g. gangetica'' and ''P. g. minor'' respectively). Genetic and morphological evidence led to their being described as separate species in 2021. The Ganges and Indus river dolphins are estimated to have Split (phylogenetics), diverged 550,000 years ago. They are the only living members of the family Platanistidae and the superfamily Platanistoidea. Fossils of ancient relatives date to the late Oligocene. South Asian river dolphins are small but stocky cetaceans with long snouts or Rostrum (anatomy), rostra, broad flippers, and small dorsal fins. They have several unusual features. Living in murky river waters, they have eyes that are tiny and lensless; the dolphins rely instead on Animal echolocation, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sagittal Crest
A sagittal crest is a ridge of bone running lengthwise along the midline of the top of the skull (at the sagittal suture) of many mammalian and reptilian skulls, among others. The presence of this ridge of bone indicates that there are exceptionally strong jaw muscles. The sagittal crest serves primarily for attachment of the temporalis muscle, which is one of the main chewing muscles. Development of the sagittal crest is thought to be connected to the development of this muscle. A sagittal crest usually develops during the juvenile stage of an animal in conjunction with the growth of the temporalis muscle, as a result of convergence and gradual heightening of the temporal lines. Function A sagittal crest tends to be present on the skulls of adult animals that rely on powerful biting and clenching of their teeth, usually as a part of their hunting strategy. Skulls of some dinosaur species, including tyrannosaurs, possessed well developed sagittal crests. Among mammals, dogs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
