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45-462: Cynognathus is an extinct genus of large-bodied cynodontian therapsids that lived in the Middle Triassic . It is known from a single species, Cynognathus crateronotus . Cynognathus was a predator closely related to mammals and had a southern hemispheric distribution. Fossils have so far been recovered from South Africa , Argentina , Antarctica , and Namibia . Cynognathus

90-407: A genus is determined by taxonomists . The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: Moreover, genera should be composed of phylogenetic units of

135-651: A later homonym of a validly published name is a nomen illegitimum or nom. illeg. ; for a full list refer to the International Code of Nomenclature for algae, fungi, and plants and the work cited above by Hawksworth, 2010. In place of the "valid taxon" in zoology, the nearest equivalent in botany is " correct name " or "current name" which can, again, differ or change with alternative taxonomic treatments or new information that results in previously accepted genera being combined or split. Prokaryote and virus codes of nomenclature also exist which serve as

180-628: A long time and redescribed as new by a range of subsequent workers, or if a range of genera previously considered separate taxa have subsequently been consolidated into one. For example, the World Register of Marine Species presently lists 8 genus-level synonyms for the sperm whale genus Physeter Linnaeus, 1758, and 13 for the bivalve genus Pecten O.F. Müller, 1776. Within the same kingdom, one generic name can apply to one genus only. However, many names have been assigned (usually unintentionally) to two or more different genera. For example,

225-409: A reference for designating currently accepted genus names as opposed to others which may be either reduced to synonymy, or, in the case of prokaryotes, relegated to a status of "names without standing in prokaryotic nomenclature". An available (zoological) or validly published (botanical) name that has been historically applied to a genus but is not regarded as the accepted (current/valid) name for

270-399: A reptilian fashion, but recent studies suggest cynodonts typically held their front legs in a posture between these two extremes. A study of living mammals concluded that "upright posture" in mammals is a myth based on the posture of mammal species specialized for fast running, such as dogs, hares, and antelopes; modern mammals that are not specialized for running often hold their forelimbs in

315-465: A semi-sprawled posture. Possible autapomorphies of C. crateronotus include an extremely elongated postorbital bar and sectorial postcanine teeth with two serrated cusps distal to a recurved apex. During 1888 and 1889, the British paleontologist Harry Govier Seeley visited southern Africa. In 1889, near Lady Frere , at a location where earlier Alfred Brown had discovered a tooth, Seeley excavated

360-417: A skull and partial postcranial skeleton of a cynodontian. In 1894, Seeley named the genus Cynognathus with as type species Cynognathus crateronotus . Simultaneously, he named three other species in the genus: Cynognathus berryi , honouring James Berry who had assisted in the excavations, Cynognathus platyceps , the "flat jaw", and Cynognathus leptorhinus , the "slender nose". The generic name Cynognathus

405-427: A taxon; however, the names published in suppressed works are made unavailable via the relevant Opinion dealing with the work in question. In botany, similar concepts exist but with different labels. The botanical equivalent of zoology's "available name" is a validly published name . An invalidly published name is a nomen invalidum or nom. inval. ; a rejected name is a nomen rejiciendum or nom. rej. ;

450-455: A total of c. 520,000 published names (including synonyms) as at end 2019, increasing at some 2,500 published generic names per year. "Official" registers of taxon names at all ranks, including genera, exist for a few groups only such as viruses and prokaryotes, while for others there are compendia with no "official" standing such as Index Fungorum for fungi, Index Nominum Algarum and AlgaeBase for algae, Index Nominum Genericorum and

495-416: Is derived from Greek kyon and gnathos , meaning "dog jaw". In 1895, Seeley published a more comprehensive description of these finds. Fossil material probably belonging to the genus has been given several different names over the years. Generic synonyms include Cynidiognathus , Cynogomphius , Karoomys , Lycaenognathus , Lycochampsa and Lycognathus . Opinions vary as to whether all remains belong to

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540-612: Is discouraged by both the International Code of Zoological Nomenclature and the International Code of Nomenclature for algae, fungi, and plants , there are some five thousand such names in use in more than one kingdom. For instance, A list of generic homonyms (with their authorities), including both available (validly published) and selected unavailable names, has been compiled by the Interim Register of Marine and Nonmarine Genera (IRMNG). The type genus forms

585-608: Is presently the only recognized member of the family Cynognathidae. Later a clade Cynognathia was named after the genus, within the Eucynodontia . Cynognathus crateronotus in a cladogram after Stefanello et al . (2023): Cynognathus crateronotus Diademodon tetragonus Langbergia modisei Trirachodon berryi Sinognathus gracilis Pascualgnathus polanskii Luangwa drysdalli Scalenodon angustifrons Mandagomphodon hirschoni Massetognathus pascuali Exaeretodon argentinus In

630-460: Is somewhat arbitrary. Although all species within a genus are supposed to be "similar", there are no objective criteria for grouping species into genera. There is much debate among zoologists about whether enormous, species-rich genera should be maintained, as it is extremely difficult to come up with identification keys or even character sets that distinguish all species. Hence, many taxonomists argue in favor of breaking down large genera. For instance,

675-474: Is the type species , and the generic name is permanently associated with the type specimen of its type species. Should the specimen turn out to be assignable to another genus, the generic name linked to it becomes a junior synonym and the remaining taxa in the former genus need to be reassessed. In zoological usage, taxonomic names, including those of genera, are classified as "available" or "unavailable". Available names are those published in accordance with

720-621: The International Code of Zoological Nomenclature ; the earliest such name for any taxon (for example, a genus) should then be selected as the " valid " (i.e., current or accepted) name for the taxon in question. Consequently, there will be more available names than valid names at any point in time; which names are currently in use depending on the judgement of taxonomists in either combining taxa described under multiple names, or splitting taxa which may bring available names previously treated as synonyms back into use. "Unavailable" names in zoology comprise names that either were not published according to

765-824: The International Plant Names Index for plants in general, and ferns through angiosperms, respectively, and Nomenclator Zoologicus and the Index to Organism Names for zoological names. Totals for both "all names" and estimates for "accepted names" as held in the Interim Register of Marine and Nonmarine Genera (IRMNG) are broken down further in the publication by Rees et al., 2020 cited above. The accepted names estimates are as follows, broken down by kingdom: The cited ranges of uncertainty arise because IRMNG lists "uncertain" names (not researched therein) in addition to known "accepted" names;

810-907: The Karoo , the Puesto Viejo Formation , Fremouw Formation , in South Africa / Lesotho , Argentina and Antarctica . Cynognathus lived between the Anisian and the Ladinian (Middle Triassic). This genus forms a Cynognathus Assemblage Zone in the Beaufort Group of the Karoo Supergroup . Seeley in 1894/1895 placed Cynognathus in a separate family Cynognathidae , within the Cynodontia . Cynognathus

855-586: The end-Permian mass extinction . The Burgersdorp Formation in South Africa is known for having a substantial amount of fossiliferous rocks. The Permo-Triassic strata of the Beaufort Group has a substantial amount of therapsid fossils which are used in the biostratigraphic subdivision. The uppermost division is the Cynognathus Assemblage Zone, this zone covers the late early and early middle Triassic. The Cynognathus Assemblage Zone

900-419: The nomenclature codes , which allow each species a single unique name that, for animals (including protists ), plants (also including algae and fungi ) and prokaryotes ( bacteria and archaea ), is Latin and binomial in form; this contrasts with common or vernacular names , which are non-standardized, can be non-unique, and typically also vary by country and language of usage. Except for viruses ,

945-404: The platypus belongs to the genus Ornithorhynchus although George Shaw named it Platypus in 1799 (these two names are thus synonyms ) . However, the name Platypus had already been given to a group of ambrosia beetles by Johann Friedrich Wilhelm Herbst in 1793. A name that means two different things is a homonym . Since beetles and platypuses are both members of the kingdom Animalia,

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990-472: The Karoo Basin in what is now South Africa, Cynognathus lived in open environments with warm, dry summers and cool, wet winters, similar to today's Western Cape region but more arid. Individuals grew rapidly and continuously. Their hunting habits were largely unaffected by the changing seasons. The dentary was equipped with differentiated teeth, with fangs in the front for seizing prey and wider teeth in

1035-442: The base for higher taxonomic ranks, such as the family name Canidae ("Canids") based on Canis . However, this does not typically ascend more than one or two levels: the order to which dogs and wolves belong is Carnivora ("Carnivores"). The numbers of either accepted, or all published genus names is not known precisely; Rees et al., 2020 estimate that approximately 310,000 accepted names (valid taxa) may exist, out of

1080-446: The form "author, year" in zoology, and "standard abbreviated author name" in botany. Thus in the examples above, the genus Canis would be cited in full as " Canis Linnaeus, 1758" (zoological usage), while Hibiscus , also first established by Linnaeus but in 1753, is simply " Hibiscus L." (botanical usage). Each genus should have a designated type , although in practice there is a backlog of older names without one. In zoology, this

1125-737: The generic name (or its abbreviated form) still forms the leading portion of the scientific name, for example, Canis lupus lupus for the Eurasian wolf subspecies, or as a botanical example, Hibiscus arnottianus ssp. immaculatus . Also, as visible in the above examples, the Latinised portions of the scientific names of genera and their included species (and infraspecies, where applicable) are, by convention, written in italics . The scientific names of virus species are descriptive, not binomial in form, and may or may not incorporate an indication of their containing genus; for example,

1170-633: The largest component, with 23,236 ± 5,379 accepted genus names, of which 20,845 ± 4,494 are angiosperms (superclass Angiospermae). By comparison, the 2018 annual edition of the Catalogue of Life (estimated >90% complete, for extant species in the main) contains currently 175,363 "accepted" genus names for 1,744,204 living and 59,284 extinct species, also including genus names only (no species) for some groups. The number of species in genera varies considerably among taxonomic groups. For instance, among (non-avian) reptiles , which have about 1180 genera,

1215-467: The lizard genus Anolis has been suggested to be broken down into 8 or so different genera which would bring its ~400 species to smaller, more manageable subsets. Langbergia modisei Langbergia is an extinct genus of trirachodontid cynodont from the Early Triassic of South Africa . The type and only species L. modisei was named in 2006 after the farm where the holotype

1260-403: The most (>300) have only 1 species, ~360 have between 2 and 4 species, 260 have 5–10 species, ~200 have 11–50 species, and only 27 genera have more than 50 species. However, some insect genera such as the bee genera Lasioglossum and Andrena have over 1000 species each. The largest flowering plant genus, Astragalus , contains over 3,000 species. Which species are assigned to a genus

1305-428: The name could not be used for both. Johann Friedrich Blumenbach published the replacement name Ornithorhynchus in 1800. However, a genus in one kingdom is allowed to bear a scientific name that is in use as a generic name (or the name of a taxon in another rank) in a kingdom that is governed by a different nomenclature code. Names with the same form but applying to different taxa are called "homonyms". Although this

1350-531: The penultimate tooth and the medial and distal basins are deep and mesiodistally short Trirachodontids Trirachodon and Cricodon have a labial platform of the maxilla that arises lateral to the postcanine series, this is not observed in Langbergia. Langbergia has been recorded having stapes, despite how fragile the structure is. Langbergia, like most other living in the Permian, went extinct during

1395-541: The provisions of the ICZN Code, e.g., incorrect original or subsequent spellings, names published only in a thesis, and generic names published after 1930 with no type species indicated. According to "Glossary" section of the zoological Code, suppressed names (per published "Opinions" of the International Commission of Zoological Nomenclature) remain available but cannot be used as the valid name for

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1440-433: The rear of the jaw suitable for cutting meat; these show this animal could effectively process its food before swallowing. The presence of a secondary palate in the mouth indicates that Cynognathus would have been able to breathe and swallow simultaneously. All these adaptations are consistent with maintaining a regular, high basal metabolic rate (" warm-blooded "), as in modern mammals. The possible lack of belly ribs, in

1485-470: The same kind as other (analogous) genera. The term "genus" comes from Latin genus , a noun form cognate with gignere ('to bear; to give birth to'). The Swedish taxonomist Carl Linnaeus popularized its use in his 1753 Species Plantarum , but the French botanist Joseph Pitton de Tournefort (1656–1708) is considered "the founder of the modern concept of genera". The scientific name (or

1530-451: The same species. The genus Karoomys is known only from a tiny juvenile. Species-level synonyms of Cynognathus crateronotus include Cynidiognathus broomi , Cynidiognathus longiceps , Cynidiognathus merenskyi , Cynognathus berryi , Cynognathus minor , Cynognathus platyceps , Cynogomphius berryi , Karoomys browni , Lycaenognathus platyceps , Lycochampsa ferox , Lycognathus ferox , and Nythosaurus browni . Fossils have been found in

1575-408: The scientific epithet) of a genus is also called the generic name ; in modern style guides and science, it is always capitalised. It plays a fundamental role in binomial nomenclature , the system of naming organisms , where it is combined with the scientific name of a species : see Botanical name and Specific name (zoology) . The rules for the scientific names of organisms are laid down in

1620-497: The specific name particular to the wolf. A botanical example would be Hibiscus arnottianus , a particular species of the genus Hibiscus native to Hawaii. The specific name is written in lower-case and may be followed by subspecies names in zoology or a variety of infraspecific names in botany . When the generic name is already known from context, it may be shortened to its initial letter, for example, C. lupus in place of Canis lupus . Where species are further subdivided,

1665-412: The standard format for a species name comprises the generic name, indicating the genus to which the species belongs, followed by the specific epithet, which (within that genus) is unique to the species. For example, the gray wolf 's scientific name is Canis lupus , with Canis ( Latin for 'dog') being the generic name shared by the wolf's close relatives and lupus (Latin for 'wolf') being

1710-442: The stomach region, suggests the presence of an efficient diaphragm , an important muscle that allows mammals to breathe equally well when they are walking, running, or holding still. Pits and canals on the bone of the snout indicate concentrations of nerves and blood vessels. In mammals, these structures support special sensory hairs ( whiskers ), so it is likely Cynognathus had whiskers as well. Genus The composition of

1755-403: The taxon is termed a synonym ; some authors also include unavailable names in lists of synonyms as well as available names, such as misspellings, names previously published without fulfilling all of the requirements of the relevant nomenclatural code, and rejected or suppressed names. A particular genus name may have zero to many synonyms, the latter case generally if the genus has been known for

1800-576: The values quoted are the mean of "accepted" names alone (all "uncertain" names treated as unaccepted) and "accepted + uncertain" names (all "uncertain" names treated as accepted), with the associated range of uncertainty indicating these two extremes. Within Animalia, the largest phylum is Arthropoda , with 151,697 ± 33,160 accepted genus names, of which 114,387 ± 27,654 are insects (class Insecta). Within Plantae, Tracheophyta (vascular plants) make up

1845-429: The virus species " Salmonid herpesvirus 1 ", " Salmonid herpesvirus 2 " and " Salmonid herpesvirus 3 " are all within the genus Salmonivirus ; however, the genus to which the species with the formal names " Everglades virus " and " Ross River virus " are assigned is Alphavirus . As with scientific names at other ranks, in all groups other than viruses, names of genera may be cited with their authorities, typically in

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1890-433: Was a heavily built animal, and measured around 1.2 metres (3 ft 11 in) in snout-to-vent body length and up to 2 metres (6 ft 7 in) in total length. It had a particularly large head, up to 40 centimetres (1 ft) in length, with wide jaws and sharp teeth. Its hindlimbs were placed directly beneath the body. There has been controversy about whether the forelimbs were also held upright or sprawled outwards in

1935-455: Was found (Langberg 566). Trirachodontids are distinguishable due to the shape of their postcanines ; the postcanines, distal to the canines, are transversely widened teeth with three main cusps disposed in a transverse row across the center of the tooth. Langbergia are small gomphodontian cynodonts. Cynodonts are a very important component of the Triassic. After the Langbergia fossil

1980-408: Was found in 2006, new diagnostic features allowed for a new taxon, Langbergia modisei. Unlike other Trirachodontids, the upper and lower gomphodont post caninines of Langbergia are elliptical in cross section, slightly labiolingually elongated and their long axis is longuomesially orientated. Additionally, both upper and lower lower gomphodont postcanines of Langbergia increase tooth size up until

2025-624: Was found, Langberg 566. Langbergia was found in the Burgersdorp Formation in the Beaufort Group , a part of the Cynognathus Assemblage Zone . The closely related trirachodontids Trirachodon and Cricodon were found in the same area. Langbergia was discovered in the Cynognathus Assemblage Zone of the Beaufort Group of South Africa in 2006. It was named after the farm where the holotype

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