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Phylonyms
The ''International Code of Phylogenetic Nomenclature'', known as the ''PhyloCode'' for short, is a formal set of rules governing phylogenetic nomenclature. Its current version is specifically designed to regulate the naming of clades, leaving the governance of species names up to the rank-based nomenclature codes ('' ICN'', ''ICNCP'', '' ICNP'', ''ICZN'', '' ICVCN''). The ''PhyloCode'' is associated with the International Society for Phylogenetic Nomenclature (ISPN). The companion volume, ''Phylonyms'', establishes 300 taxon names under ''PhyloCode'', serving as examples for those unfamiliar with the code. RegNum is an associated online database for registered clade names. The ''PhyloCode'' regulates phylogenetic nomenclature by providing rules for deciding which associations of names and definitions are considered established, which of those will be considered homonyms or synonyms, and which one of a set of synonyms or homonyms will be considered accepted (generally the one regi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nomenclature Code
Nomenclature codes or codes of nomenclature are the various rulebooks that govern the naming of living organisms. Standardizing the scientific names of biological organisms allows researchers to discuss findings (including the discovery of new species). As the study of biology became increasingly specialized, specific codes were adopted for different types of organism. To an end-user who only deals with names of species, with some awareness that species are assignable to genera, families, and other taxa of higher ranks, it may not be noticeable that there is more than one code, but beyond this basic level these are rather different in the way they work. Binomial Nomenclature In taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages. Suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenetic Nomenclature
Phylogenetic nomenclature is a method of nomenclature for taxa in biology that uses phylogenetic definitions for taxon names as explained below. This contrasts with the traditional method, by which taxon names are defined by a '' type'', which can be a specimen or a taxon of lower rank, and a description in words. Phylogenetic nomenclature is regulated currently by the '' International Code of Phylogenetic Nomenclature'' (''PhyloCode''). Definitions Phylogenetic nomenclature associates names with clades, groups consisting of an ancestor and all its descendants. Such groups are said to be monophyletic. There are slightly different methods of specifying the ancestor, which are discussed below. Once the ancestor is specified, the meaning of the name is fixed: the ancestor and all organisms which are its descendants are included in the taxon named. Listing all these organisms (i.e. providing a full circumscription) requires the complete phylogenetic tree to be known. In practice, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family (biology)
Family (, : ) 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". The delineation of what constitutes a family—or whether a described family should be acknowledged—is established and decided upon by active taxonomists. There are not strict regulations for outlining or acknowledging a family, yet in the realm of plants, these classifications often rely on both the vegetative and reproductive characteristics of plant species. Taxonomists frequently hold varying perspectives on these descriptions, leading to a lack of widespread consensus within the scientific community ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammalia
A mammal () is a vertebrate animal of the class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three middle ear bones. These characteristics distinguish them from reptiles and birds, from which their ancestors diverged in the Carboniferous Period over 300 million years ago. Around 6,640 extant species of mammals have been described and divided into 27 orders. The study of mammals is called mammalogy. The largest orders of mammals, by number of species, are the rodents, bats, and eulipotyphlans (including hedgehogs, moles and shrews). The next three are the primates (including humans, monkeys and lemurs), the even-toed ungulates (including pigs, camels, and whales), and the Carnivora (including cats, dogs, and seals). Mammals are the only living members of Synapsida; this clade, together with Sauropsida (reptiles and birds), constitut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albertosaurus Sarcophagus
''Albertosaurus'' (; meaning "Alberta lizard") is a genus of large tyrannosaurid theropod dinosaur that lived in northwestern North America during the early to middle Maastrichtian age of the Late Cretaceous period, about 71 million years ago. The type species, ''A. sarcophagus'', was apparently restricted in range to the modern-day Canadian province of Alberta, after which the genus is named, although an indeterminate species ("cf. ''Albertosaurus'' sp.") has been discovered in the Corral de Enmedio and Packard Formations of Mexico. Scientists disagree on the content of the genus and some recognize '' Gorgosaurus libratus'' as a second species. As a tyrannosaurid, ''Albertosaurus'' was a bipedal predator with short arms, two-fingered hands, and a massive head with dozens of large, sharp teeth, a strong sense of smell, powerful binocular vision, and a bone crushing bite force. It may have even been the apex predator in its local ecosystem. While ''Albertosaurus'' was c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gorgosaurus Libratus
''Gorgosaurus'' ( ; ) is a genus of tyrannosaurid theropod dinosaur that lived in western North America during the Late Cretaceous Period (geology), Period (Campanian), between about 76.5 and 75 million years ago. Fossil remains have been found in the Provinces and territories of Canada, Canadian province of Alberta and the U.S. state of Montana. Paleontologists recognize only the type species, ''G. libratus'', although other species have been erroneously referred to the genus. Like most known tyrannosaurids, ''Gorgosaurus'' was a large bipedal predation, predator, measuring in length and in body mass. Dozens of large, sharp teeth lined its jaws, while its two-fingered forelimbs were comparatively small. ''Gorgosaurus'' was most closely related to ''Albertosaurus'', and more distantly related to the larger ''Tyrannosaurus''. ''Gorgosaurus'' and ''Albertosaurus'' are extremely similar, distinguished mainly by subtle differences in the teeth and skull bones. Some experts c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tyrannosaurus Rex
''Tyrannosaurus'' () is a genus of large theropoda, theropod dinosaur. The type species ''Tyrannosaurus rex'' ( meaning 'king' in Latin), often shortened to ''T. rex'' or colloquially t-rex, is one of the best represented theropods. It lived throughout what is now western North America, on what was then an island continent known as Laramidia. ''Tyrannosaurus'' had a much wider range than other Tyrannosauridae, tyrannosaurids. Fossils are found in a variety of geological formations dating to the latest Campanian-Maastrichtian Age (geology), ages of the late Cretaceous Period (geology), period, 72.7 to 66 mya (unit), million years ago, with isolated specimens possibly indicating an earlier origin in the middle Campanian. It was the last known member of the tyrannosaurids and among the last non-Bird, avian dinosaurs to exist before the Cretaceous–Paleogene extinction event. Like other tyrannosaurids, ''Tyrannosaurus'' was a bipedal carnivore with a massive skull balanced ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tyrannosaurus
''Tyrannosaurus'' () is a genus of large theropod dinosaur. The type species ''Tyrannosaurus rex'' ( meaning 'king' in Latin), often shortened to ''T. rex'' or colloquially t-rex, is one of the best represented theropods. It lived throughout what is now western North America, on what was then an island continent known as Laramidia. ''Tyrannosaurus'' had a much wider range than other tyrannosaurids. Fossils are found in a variety of geological formations dating to the latest Campanian-Maastrichtian ages of the late Cretaceous period, 72.7 to 66 million years ago, with isolated specimens possibly indicating an earlier origin in the middle Campanian. It was the last known member of the tyrannosaurids and among the last non- avian dinosaurs to exist before the Cretaceous–Paleogene extinction event. Like other tyrannosaurids, ''Tyrannosaurus'' was a bipedal carnivore with a massive skull balanced by a long, heavy tail. Relative to its large and powerful hind limbs, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tyrannosauridae
Tyrannosauridae (or tyrannosaurids, meaning "tyrant lizards") is a family of coelurosaurian theropod dinosaurs that comprises two subfamilies containing up to fifteen genera, including the eponymous ''Tyrannosaurus''. The exact number of genera is controversial, with some experts recognizing as few as three. All of these animals lived near the end of the Cretaceous Period and their fossils have been found only in North America and Asia. Although descended from smaller ancestors, tyrannosaurids were almost always the largest predators in their respective ecosystems, putting them at the apex of the food chain. The largest species was ''Tyrannosaurus rex'', the most massive known terrestrial predator, which measured over in length and according to most modern estimates up to in weight. Tyrannosaurids were bipedal carnivores with massive skulls filled with large teeth. Despite their large size, their legs were long and proportioned for fast movement. In contrast, their arms were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crown Group
In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. It is thus a way of defining a clade, a group consisting of a species and all its extant or extinct descendants. For example, Neornithes (birds) can be defined as a crown group, which includes the most recent common ancestor of all modern birds, and all of its extant or extinct descendants. The concept was developed by Willi Hennig, the formulator of phylogenetic systematics, as a way of classifying living organisms relative to their extinct relatives in his "Die Stammesgeschichte der Insekten", and the "crown" and "stem" group terminology was coined by R. P. S. Jefferies in 1979. Though formulated in the 1970s, the term was not commonly used until its reintroduction in 2000 by Graham Budd and Sören Jensen. Contents of the crow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extant Taxon
Neontology is a part of biology that, in contrast to paleontology, studies and deals with living (or, more generally, '' recent'') organisms. It is the study of extant taxa (singular: extant taxon): taxa (such as species, genera and families) with members still alive, as opposed to (all) being extinct. For example: * The Indian elephant (''Elephas maximus'') is an extant species, and the woolly mammoth (''Mammuthus primigenius'') is an extinct species. * The moose (''Alces alces'') is an extant species, and the Irish elk (''Megaloceros giganteus'') is an extinct species. * In the group of molluscs known as the cephalopods, there were approximately 600 extant species and 7,500 extinct species. A taxon can be classified as extinct if it is broadly agreed or certified that no members of the group are still alive. Conversely, an extinct taxon can be reclassified as extant if there are new discoveries of living species (" Lazarus species"), or if previously known extant species ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
