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Pecorans
Pecora is an infraorder of even-toed hoofed mammals with ruminant digestion. Most members of Pecora have cranial appendages projecting from their frontal bones; only two extant genera lack them, ''Hydropotes'' and ''Moschus''. The name “Pecora” comes from the Latin word ''pecus'', which means “horned livestock”.Bubenik, A. Epigenetical, Morphological, Physiological, and Behavioral Aspects of Evolution of Horns, Pronghorns, and Antlers. in ''Horns, Pronghorns, and Antlers''. G. Bubenik and A. Bubenik eds. Springer-Verlag. New York. 1990 Although most pecorans have cranial appendages, only some of these are properly called “horns”, and many scientists agree that these appendages did not arise from a common ancestor, but instead evolved independently on at least two occasions.Janis, C., K. Scott. The Interrelationships of Higher Ruminant Families with Special Emphasis on the Members of the Cervoidea. ''American Museum Novitates''. 2893: 1-85. 1987. http://digitallibrary. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Giraffidae
The Giraffidae are a family of ruminant artiodactyl mammals that share a common ancestor with deer and bovids. This family, once a diverse group spread throughout Eurasia and Africa, presently comprises only two extant genera, the giraffe (one or more species of ''Giraffa'', depending on taxonomic interpretation) and the okapi (the only known species of ''Okapia''). Both are confined to sub-Saharan Africa: the giraffe to the open savannas, and the okapi to the dense rainforest of the Congo. The two genera look very different on first sight, but share a number of common features, including a long, dark-coloured tongue, lobed canine teeth, and horns covered in skin, called ossicones. Taxonomy Evolutionary background The giraffids are ruminants of the clade Pecora. Other extant pecorans are the families Antilocapridae (pronghorns), Cervidae (deer), Moschidae (musk deer), and Bovidae (cattle, goats and sheep, wildebeests and allies, and antelopes). The exact interrelationships a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antilocapridae
The Antilocapridae are a family of artiodactyls endemic to North America. Their closest extant relatives are the giraffids with which they comprise the superfamily Giraffoidea. Only one species, the pronghorn (''Antilocapra americana''), is living today; all other members of the family are extinct. The living pronghorn is a small ruminant mammal resembling an antelope. Description In most respects, antilocaprids resemble other ruminants. They have a complex, four-chambered stomach for digesting tough plant matter, cloven hooves, and small, forked horns. Their horns resemble those of the bovids, in that they have a true horny sheath, but, uniquely, they are shed outside the breeding season, and subsequently regrown. Their lateral toes are even further diminished than in bovids, with the digits themselves being entirely lost, and only the cannon bones remaining. Antilocaprids have the same dental formula as most other ruminants: . Classification The antilocaprids are ruminants o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bovidae
The Bovidae comprise the biological family of cloven-hoofed, ruminant mammals that includes cattle, bison, buffalo, antelopes, and caprines. A member of this family is called a bovid. With 143 extant species and 300 known extinct species, the family Bovidae consists of 11 (or two) major subfamilies and thirteen major tribes. The family evolved 20 million years ago, in the early Miocene. The bovids show great variation in size and pelage colouration. Excepting some domesticated forms, all male bovids have two or more horns, and in many species, females possess horns, too. The size and shape of the horns vary greatly, but the basic structure is always one or more pairs of simple bony protrusions without branches, often having a spiral, twisted or fluted form, each covered in a permanent sheath of keratin. Most bovids bear 30 to 32 teeth. Most bovids are diurnal. Social activity and feeding usually peak during dawn and dusk. Bovids typically rest before dawn, during midday ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sister Taxon
In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and taxon B are sister groups to each other. Taxa A and B, together with any other extant or extinct descendants of their most recent common ancestor (MRCA), form a monophyletic group, the clade AB. Clade AB and taxon C are also sister groups. Taxa A, B, and C, together with all other descendants of their MRCA form the clade ABC. The whole clade ABC is itself a subtree of a larger tree which offers yet more sister group relationships, both among the leaves and among larger, more deeply rooted clades. The tree structure shown connects through its root to the rest of the universal tree of life. In cladistic standards, taxa A, B, and C may represent specimens, species, genera, or any other taxonomic units. If A and B are at the same taxonomi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clade
A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, the equivalent Latin term ''cladus'' (plural ''cladi'') is often used in taxonomical literature. The common ancestor may be an individual, a population, or a species (extinct or extant). Clades are nested, one in another, as each branch in turn splits into smaller branches. These splits reflect evolutionary history as populations diverged and evolved independently. Clades are termed monophyletic (Greek: "one clan") groups. Over the last few decades, the cladistic approach has revolutionized biological classification and revealed surprising evolutionary relationships among organisms. Increasingly, taxonomists try to avoid naming taxa that are not clades; that is, taxa that are not monophyletic. Some of the relationships between organisms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tragulina
Tragulina (also known as Traguliformes) is an infraorder of even-toed ungulates. Only the chevrotains survive to the present, including the genera ''Tragulus'' (the mouse deer) and ''Hyemoschus'', all within the family Tragulidae. Taxonomy and Classification Tragulina is an infraorder within the larger suborder Ruminantia, and is the sister clade to the infraorder Pecora. Tragulina contains one extant (living) family, Tragulidae, as well as several extinct families, although the extinct members currently classified as within Tragulina causes it to be considered paraphyletic. Tragulina's placement within Artiodactyla can be represented in the following cladogram:(see e.g. Fig S10) The following is the taxonomy of the group Tragulina. *Infrarorder TRAGULINA **† Praetragulidae ***'' Praetragulus'' ***'' Parvitragulus'' ***'' Simimeryx'' **† Archaeomerycidae ***'' Archaeomeryx'' ***'' Miomeryx'' ***'' Paukkaungmeryx'' **†Gelocidae ***'' Phaneromeryx'' ***'' Paragelocus' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tragulidae
The asterisk ( ), from Late Latin , from Ancient Greek , ''asteriskos'', "little star", is a typographical symbol. It is so called because it resembles a conventional image of a heraldic star. Computer scientists and mathematicians often vocalize it as star (as, for example, in ''the A* search algorithm'' or ''C*-algebra''). In English, an asterisk is usually five- or six-pointed in sans-serif typefaces, six-pointed in serif typefaces, and six- or eight-pointed when handwritten. Its most common use is to call out a footnote. It is also often used to censor offensive words. In computer science, the asterisk is commonly used as a wildcard character, or to denote pointers, repetition, or multiplication. History The asterisk has already been used as a symbol in ice age cave paintings. There is also a two thousand-year-old character used by Aristarchus of Samothrace called the , , which he used when proofreading Homeric poetry to mark lines that were duplicated. Origen is know ... [...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 opini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladogram
A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to descendants, nor does it show how much they have changed, so many differing evolutionary trees can be consistent with the same cladogram. A cladogram uses lines that branch off in different directions ending at a clade, a group of organisms with a last common ancestor. There are many shapes of cladograms but they all have lines that branch off from other lines. The lines can be traced back to where they branch off. These branching off points represent a hypothetical ancestor (not an actual entity) which can be inferred to exhibit the traits shared among the terminal taxa above it. This hypothetical ancestor might then provide clues about the order of evolution of various features, adaptation, and other evolutionary narratives about ance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Eocene
In the geologic timescale the Ypresian is the oldest age or lowest stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by the Eocene Lutetian Age. The Ypresian is consistent with the lower Eocene. Events The Ypresian Age begins during the throes of the Paleocene–Eocene Thermal Maximum (PETM). The Fur Formation in Denmark, the Messel shales in Germany, the Oise amber of France and Cambay amber of India are of this age. The Eocene Okanagan Highlands are an uplands subtropical to temperate series of lakes from the Ypresian. Stratigraphic definition The Ypresian Stage was introduced in scientific literature by Belgian geologist André Hubert Dumont in 1850. The Ypresian is named after the Flemish city of Ypres in Belgium (spelled ''Ieper'' in Dutch). The definitions of the original stage were totally different from the modern ones. The Ypresian shares its name with the Belgian Ieper Group (French: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene is preceded by the Oligocene and is followed by the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by a single distinct global event but consist rather of regionally defined boundaries between the warmer Oligocene and the cooler Pliocene Epoch. During the Early Miocene, the Arabian Peninsula collided with Eurasia, severing the connection between the Mediterranean and Indian Ocean, and allowing a faunal interchange to occur between Eurasia and Africa, including the dispersal of proboscideans into Eurasia. During the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tylopoda
Tylopoda (meaning "calloused foot") is a suborder of terrestrial herbivorous even-toed ungulates belonging to the order Artiodactyla. They are found in the wild in their native ranges of South America and Asia, while Australian feral camels are introduced. The group has a long fossil history in North America and Eurasia. Tylopoda appeared during the Eocene around 50 million years ago. Tylopoda has only one extant family, Camelidae, which includes camels, llamas, guanacos, alpacas and vicuñas. This group was much more diverse in the past, containing a number of extinct families in addition to the ancestors of living camelids (see below). Tylopods are not ruminants. Taxonomy and systematics Tylopoda was named by Illiger (1811) and considered monophyletic by Matthew (1908). It was treated as an unranked clade by Matthew (1908) and as a suborder by Carroll (1988), Ursing et al. (2000) and Whistler and Webb (2005). It was assigned to Ruminantia by Matthew (1908); to Artiodactyla b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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