|
Llanocetus
''Llanocetus'' ( "Llano's whale" ) is a genus of extinct toothed baleen whales from the Late Eocene of Antarctica. The type species, ''Llanocetus denticrenatus'', reached gigantic proportions, with the juvenile specimen reaching an estimated in length; a second, unnamed species, known only from three isolated premolar teeth, reached an estimated total body length of up to . Like other contemporary baleen whales of the Eocene, ''Llanocetus'' completely lacked baleen in its jaws. It was probably a suction feeder like the modern beaked and pygmy right whales. History ''Llanocetus'' was described in 1989 by paleontologist Edward Mitchell based on a partial mandible with two teeth, specimen USNM 183022, and an endocast of the braincase, referred to the same specimen, from the La Meseta Formation of Seymour Island, Antarctica. They were excavated in 1974-75 by a joint team from the Instituto Antártico Argentino, Ohio State University and Northern Illinois University. The comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Llanocetidae
Llanocetidae is an extinct family of ancient toothed baleen whales from the Eocene. It was named by American paleontologist Edward Mitchell in 1989 after describing the Antarctic ''Llanocetus'', but a 2018 study by paleontologists Ewan Fordyce Ewan is an anglicisation of the Scottish Gaelic name Eòghann. It is possibly a derivative of the Pictish name, ''Vuen'' (or 'Wen'), "The Warrior" or "born of the mountain". It is most common as a male given name in Scotland and Canada. It is a ... and Felix Marx included the Peruvian '' Mystacodon'' and an undescribed New Zealand specimen OU GS10897. References Baleen whales Eocene cetaceans Fossil taxa described in 1989 {{Paleo-whale-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baleen Whale
Baleen whales ( systematic name Mysticeti), also known as whalebone whales, are a parvorder of carnivorous marine mammals of the infraorder Cetacea ( whales, dolphins and porpoises) which use keratinaceous baleen plates (or "whalebone") in their mouths to sieve planktonic creatures from the water. Mysticeti comprises the families Balaenidae ( right and bowhead whales), Balaenopteridae (rorquals and the gray whale), and Cetotheriidae (the pygmy right whale). There are currently 16 species of baleen whales. While cetaceans were historically thought to have descended from mesonychids, molecular evidence instead supports them as a clade of even-toed ungulates (Artiodactyla). Baleen whales split from toothed whales (Odontoceti) around 34 million years ago. Baleen whales range in size from the and pygmy right whale to the and blue whale, the largest known animal to have ever existed. They are sexually dimorphic. Baleen whales can have streamlined or large bodies, depend ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mystacodon
''Mystacodon'' is a genus of toothed baleen whale from the Late Eocene Yumaque Formation of the Pisco Basin in southwestern Peru. It is the oldest known baleen whale, and was probably a suction feeder of small prey on the seafloor. Taxonomy ''Mystacodon'' is the oldest known baleen whale, the holotype specimen dating to 36.4 million year ago to the Priabonian of the latest Eocene. The holotype, MUSM 1917, comprises the braincase, teeth, the spinal cord excluding the sacral vertebrae, some fin bones, and the left hip bone. It was originally classified into its own family, Mystacodontidae, but it was moved to the family Llanocetidae in 2018 alongside ''Llanocetus''–the second-oldest baleen whale–and an undescribed New Zealand specimen OU GS10897. The genus name, ''Mystacodon'' is said to be derived from ancient Greek ''mystacos'' "moustache" and odontos "tooth". The proper words in ancient Greek for "moustache" and "tooth" are however μύσταξ (') and ὀδούς ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
La Meseta Formation
The La Meseta Formation is a sedimentary sequence deposited during the Eocene. The formation is found on Seymour Island, Antarctica. Description La Meseta Formation lies unconformably on the Cretaceous Lopez de Bertodano Formation. It is an approximately thick sequence of poorly consolidated sandstones and siltstones. The depositional environment was probably coastal, deltaic or estuarine in character. The top of the sequence is an erosional unconformity to Pleistocene glacial gravels. La Meseta Formation is one of the sequences that make up the fill of the Late Jurassic to Paleogene James Ross Basin. Fossil content La Meseta Formation is extremely rich in fossils. Among mammals, the meridiungulata ''Antarctodon'' and ''Trigonostylops'' have been found in the formation.''Antarctodon'' at |
Priabonian
The Priabonian is, in the ICS's geologic timescale, the latest age or the upper stage of the Eocene Epoch or Series. It spans the time between . The Priabonian is preceded by the Bartonian and is followed by the Rupelian, the lowest stage of the Oligocene. Stratigraphic definition The Priabonian Stage was introduced in scientific literature by Ernest Munier-Chalmas and Albert de Lapparent in 1893. The stage is named after the small hamlet of Priabona in the community of Monte di Malo, in the Veneto region of northern Italy. The base of the Priabonian Stage is at the first appearance of calcareous nannoplankton species ''Chiasmolithus oamaruensis'' (which forms the base of nanoplankton biozone NP18). An official GSSP was ratified in 2020, and was placed in the Alano di Piave section in Alano di Piave, Belluno, Italy. The top of the Priabonian Stage (the base of the Rupelian Stage and Oligocene Series) is at the extinction of foram genus ''Hantkenina''. Sometime ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mandible
In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bone of the skull (discounting the ossicles of the middle ear). It is connected to the temporal bones by the temporomandibular joints. The bone is formed in the fetus from a fusion of the left and right mandibular prominences, and the point where these sides join, the mandibular symphysis, is still visible as a faint ridge in the midline. Like other symphyses in the body, this is a midline articulation where the bones are joined by fibrocartilage, but this articulation fuses together in early childhood.Illustrated Anatomy of the Head and Neck, Fehrenbach and Herring, Elsevier, 2012, p. 59 The word "mandible" derives from the Latin word ''mandibula'', "jawbone" (literally "one used for chewing"), from '' mandere'' "to chew" and ''-bula'' (ins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Otago
, image_name = University of Otago Registry Building2.jpg , image_size = , caption = University clock tower , motto = la, Sapere aude , mottoeng = Dare to be wise , established = 1869; 152 years ago , type = Public research collegiate university , endowment = NZD $279.9 million (31 December 2021) , budget = NZD $756.8 million (31 December 2020) , chancellor = Stephen Higgs , vice_chancellor = David Murdoch , administrative_staff = 2,246 (2019) , academic_staff = 1,744 (2019) , students = 21,240 (2019) , undergrad = 15,635 (2014) , postgrad = 4,378 (2014) , doctoral = 1,579 (2019) , other = , city = Dunedin , province = Otago , country = New Zealand (Māori: ''Ōtepoti, Ōtākou, Aotearoa'') , coor = , campus = Urban/ University town 45 ha (111 acres) , colours = Dunedin Blue and Gold , free_label = Student Magazine , free = ''Critic'' , affiliations = MNU , website https://www.otago.ac.nz, logo = Logo of the University of Otago.svg The U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family (biology)
Family ( la, familia, plural ') is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae, but that family is commonly referred to as the "walnut family". What belongs to a family—or if a described family should be recognized at all—are proposed and determined by practicing taxonomists. There are no hard rules for describing or recognizing a family, but in plants, they can be characterized on the basis of both vegetative and reproductive features of plant species. Taxonomists often take different positions about descriptions, and there may be no broad consensus across the scientific community for some time. The publishing of new data and opin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene
The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). 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. 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 comparison with the more common isotope 12C. The end is set at a major extinction event called the ''Grande Coupure'' (the "Great Break" in continuity) or the Eocene–Oligocene extinction event, which may be related to the impact of one or more large bolides in Siberia and in what is now Chesapeake Bay. As with other geologic periods, the strata that define the start and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeoceti
Archaeoceti ("ancient whales"), or Zeuglodontes in older literature, is a 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 capable during the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infraorder
Order ( la, ordo) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized by the nomenclature codes. An immediately higher rank, superorder, is sometimes added directly above order, with suborder directly beneath order. An order can also be defined as a group of related families. What does and does not belong to each order is determined by a taxonomist, as is whether a particular order should be recognized at all. Often there is no exact agreement, with different taxonomists each taking a different position. There are no hard rules that a taxonomist needs to follow in describing or recognizing an order. Some taxa are accepted almost universally, while others are recognized only rarely. The name of an order is usually written with a capital letter. For some groups of organisms, their orders may follo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epiphyses
The epiphysis () is the rounded end of a long bone, at its joint with adjacent bone(s). Between the epiphysis and diaphysis (the long midsection of the long bone) lies the metaphysis, including the epiphyseal plate (growth plate). At the joint, the epiphysis is covered with articular cartilage; below that covering is a zone similar to the epiphyseal plate, known as subchondral bone. The epiphysis is filled with red bone marrow, which produces erythrocytes (red blood cells). Structure There are four types of epiphysis: # Pressure epiphysis: The region of the long bone that forms the joint is a pressure epiphysis (e.g. the head of the femur, part of the hip joint complex). Pressure epiphyses assist in transmitting the weight of the human body and are the regions of the bone that are under pressure during movement or locomotion. Another example of a pressure epiphysis is the head of the humerus which is part of the shoulder complex. condyles of femur and tibia also comes u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
