A definition is a statement of the meaning of a term. Definitions can be classified into two large categories: intensional definitions, and extensional definitions. Another important category of definitions is the class of ostensive definitions, which convey the meaning of a term by pointing out examples. A term may have many different senses and multiple meanings, and thus require multiple definitions.
In taxonomy, binomial nomenclature, 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. Such a name is called a binomial name, a binomen, binominal name, or a scientific name; more informally it is also historically called a Latin name. In the ICZN, the system is also called binominal nomenclature, "binomi'N'al" with an "N" before the "al", which is not a typographic error, meaning "two-name naming system".
The skimmers, forming the genus Rynchops, are tern-like birds in the family Laridae. The genus comprises three species found in South Asia, Africa, and the Americas. They were formerly known as the scissorbills.
The four species of avocets are a genus, Recurvirostra, of waders in the same avian family as the stilts. The genus name comes from Latin recurvus, 'curved backwards' and rostrum, 'bill'. The common name is thought to derive from the Italian (Ferrarese) word avosetta. Francis Willughby in 1678 noted it as the "Avosetta of the Italians".
Tragelaphus is a genus of medium-to-large-sized spiral-horned antelopes. It contains several species of bovines, all of which are relatively antelope-like. Species in this genus tend to be large in size and lightly built, and have long necks and considerable sexual dimorphism. Elands, including the common eland, are embedded within this genus, meaning that Taurotragus must be subsumed into Tragelaphus to avoid paraphyly. Alternatively, Taurotragus could be maintained as a separate genus, if the nyala and the lesser kudu are relocated to their own monospecific genera, respectively Nyala and Ammelaphus. Other generic synonyms include Strepsiceros and Boocercus. The name "Tragelaphus" comes from the mythical tragelaph.
The abbreviation cf. is used in writing to refer the reader to other material to make a comparison with the topic being discussed. Style guides recommend that "cf." be used only to suggest a comparison, and the words "see" or "vide" be used generally to point to a source of information.
Yimenosaurus is an extinct genus of plateosaurid sauropodomorph dinosaur that lived in China in the Early Jurassic. The genus was first named in 1990 by Ziqi Bai, Jie Yang and Guohui Wang, along with its type and only species, Yimenosaurus youngi. The species name honours renowned Chinese paleontologist Yang Zhongjian, the father of Chinese paleontology, known as C.C. Young in English. Known material includes the holotype, an almost complete skull and mandible, as well as incomplete cervical and dorsal vertebrae, a mostly complete sacrum, an ilium, ischia, partial ribs and complete femur, and a paratype, a well-preserved postcrania with a fragmentary skull. In 2010 Paul estimated its length at 9 metres (30 ft) and its weight at 2 tonnes.
Campylodoniscus is a genus of titanosaur sauropod dinosaur from the Late Cretaceous Period of what is now Argentina.
In biology, taxonomic rank is the relative level of a group of organisms in an ancestral or hereditary hierarchy. A common system of biological classification (taxonomy) consists of species, genus, family, order, class, phylum, kingdom, and domain. While older approaches to taxonomic classification were phenomenological, forming groups on the basis of similarities in appearance, organic structure and behaviour, methods based on genetic analysis have opened the road to cladistics.
Sahonachelys is an extinct genus of pelomedusoid turtle from the Late Cretaceous (Maastrichtian) Maevarano Formation of Madagascar. The genus contains a single species, Sahonachelys mailakavava.
Meemannavis is a genus of ornithuromorph bird from the Early Cretaceous (Aptian) Xiagou Formation of Gansu Province, China. The genus contains a single species, Meemannavis ductrix, known from a partial skeleton including an incomplete skull and cervical and thoracic vertebrae. The lower jaw and tip of the upper jaw of the Meemannavis holotype are toothless, but it may have had teeth nearer the back of the upper jaw.
Brevidentavis is a genus of ornithuromorph bird from the Early Cretaceous (Aptian) Xiagou Formation of Gansu Province, China. The genus contains a single species, Brevidentavis zhangi, known from a specimen including a partial skull and cervical vertebrae. The Brevidentavis holotype shows unusually blunt teeth in its lower jaw, which the describing authors suggest may indicate a specialized diet. Its dentition shows similarities with those of hesperornitheans, and indeed it may be an early member of that group.
Musivavis is a genus of euenantiornithine bird from the Early Cretaceous (Aptian) Jiufotang Formation of Liaoning Province, China. The genus contains a single species, Musivavis amabilis, known from a nearly complete, articulated skeleton.
Bounodus is an extinct genus of ungulates native from South America, belonging to the order Litopterna. Its remains were found in Miocene rocks from the Urumaco Formation of northern Venezuela. The genus is only known from its holotype, AMU-CURS 44, a fragmentary right maxilla preserving teeth from the fourth premolar to the third molar and the alveolus of the third premolar, exhibiting a typical bunodont structure in the animal dentition, a characteristic shared with its close relative Megadolodus. The postcranial skeleton of the genus is unknown. Its dentition indicates that the animal was omnivorous, with teeth adapted to potentially eat shelled fruits, as well as the molluscs and crustaceans that thrived in the wetlands that covered most of North-West South America, including the Urumaco Formation, during the Neogene.
Paralitherizinosaurus is an extinct genus of therizinosaurid dinosaur from the Late Cretaceous Osoushinai Formation of Hokkaido, Japan. The genus contains a single species, P. japonicus, known from a partial right hand and cervical vertebra. Paralitherizinosaurus represents the youngest therizinosaur known from Japan.
Paranisolambda is an extinct genus of proterotheriid litopterns from the Early to Middle Eocene of Brazil. Fossils of Paranisolambda have been recovered from the Itaboraí Formation in the Brazilian state of Rio de Janeiro.
Stenoscelida is a genus of proterochampsid archosauriforms from the Late Triassic Santa Maria Supersequence of Rio Grande do Sul, Brazil. The genus contains a single species, S. aurantiacus, known from a right hind limb.
Transylvanosaurus is an extinct genus of rhabdodontid ornithopod dinosaur from the Late Cretaceous (Maastrichtian) Hateg Basin of Romania. The type species is Transylvanosaurus platycephalus, known from a fragmentary skull.
Cratonavis is an extinct genus of pygostylian avialian from the Early Cretaceous Jiufotang Formation of Liaoning Province, China. The genus contains a single species, C. zhui, known from a complete skeleton.
