Misplaced Pages

#805194

53-560: Jianchangosaurus is a genus of therizinosaurian dinosaur that lived approximately 126 million years ago during the early part of the Cretaceous Period from the Yixian Formation in what is now China . The nearly complete juvenile specimen was missing only the distal tail. Jianchangosaurus was a small, lightly built, bipedal , ground-dwelling herbivore , that could grow up to an estimated 2 m (6.6 ft) long and

106-437: A condition that is similar to that of other basal therizinosaurs. The humerus measures 158.5 mm (6.2 in) in length and is 7% shorter than the scapula. The ulna measures 12.43 cm (124.3 mm) in length and is 78% of the humerus length - which approximates the ratio observed in the basal therizinosaur Falcarius (77%). The pubis is 20% longer than the ischium, and it projects anteroventrally and does not exhibit

159-407: 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

212-643: 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

265-621: 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,

318-401: A much smaller septomaxilla bone, lying immediately behind the nasal opening, but this is lost in most modern species. The lacrimal bone is often smaller in living vertebrates, and is no longer always directly associated with the nasal opening, although it retains its connection with the orbit. The bone is entirely absent in living amphibians , as well as some reptilian species. In dinosaurs,

371-409: 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

424-506: A series of wide and unbranched feathers were discovered with the fossils. Only the distal ends of the feather impressions are visible. Based on their morphology the feathers are considered primitive and bear resemblance to those found along the neck of Beipiaosaurus , which were collected in the same formation . The authors noted that the "presence of elongated broad filamentous feathers (EBFF) suggests that they might have been used for visual display". The only known Jianchangosaurus skeleton

477-427: 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. ;

530-455: 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

583-435: Is a juvenile. This condition, however, is also observed in adult basal therizinosaurs. The validity of Jianchangosaurus was called into question by Cau (2024), who considered it to be a junior synonym of the contemporary Beipiaosaurus since the diagnosis distinguishing the taxa was based on ontogenetically variable characters. As such, Jianchangosaurus would represent a less mature individual of Beipiaosaurus . Like

SECTION 10

#1733085613806

636-596: 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

689-400: Is extensive contact between the pubic apron. The skull is in good preservation and is nearly complete, missing only the ventral lacrimal , the posterior jugal , the postorbital , the anterior edge of the quadrate , and the anterior surangular bones. Jianchangosaurus possesses 27 maxillary teeth and approximately 25 to 28 dentary teeth. The researchers observed, however, that at front of

742-460: 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,

795-482: Is that of a juvenile individual. The morphological evidence supporting ontogenetic immaturity consists of the observation that the neurocentral sutures are open (i.e. not fused) in all of the cervical and dorsal vertebrae, as well as in the cervical ribs and in the sacral centra. The scapula and coracoid are also unfused, which the authors indicate may be an ontogenetic feature in Jianchangosaurus also suggesting that

848-474: 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

901-621: 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

954-799: 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;

1007-440: The lacrimal sulcus ( sulcus lacrimalis ), the inner margin of which unites with the frontal process of the maxilla , and the lacrimal fossa is thus completed. The upper part of this fossa lodges the lacrimal sac , the lower part, the nasolacrimal duct . The portion behind the crest is smooth, and forms part of the medial wall of the orbit. The crest, with a part of the orbital surface immediately behind it, gives origin to

1060-405: The nasopharynx . This drainage results in what is commonly referred to a runny nose during excessive crying or tear production. Injury or fracture of the lacrimal bone can result in posttraumatic obstruction of the lacrimal pathways. The lateral or orbital surface is divided by a vertical ridge, the posterior lacrimal crest , into two parts. In front of this crest is a longitudinal groove,

1113-419: 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 ,

SECTION 20

#1733085613806

1166-422: The opisthopubic condition. The tibia (31.6 cm (316 mm)) is 1.5 times longer than the femur (20.6 cm (206 mm)), which is the highest ratio known in therizinosaurs, an adaptation which has been strongly correlated with the development of cursorial habits in dinosaurs. According to Pu et al. 2013, Jianchangosaurus can be distinguished based on the presence of 27 tightly packed maxillary teeth;

1219-404: 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,

1272-502: The type species is Jianchangosaurus yixianensis . The holotype specimen of Jianchangosaurus 41HIII-0308A is a nearly complete skeleton of a single juvenile individual, missing only the distal portion of the tail. Jianchangosaurus was estimated to have been 1 m (3.3 ft) tall at the hips and approximately 2 m (6.6 ft) long. Gregory S. Paul estimated the weight of the holotype specimen around 20 kg (44 lb). Five sacral vertebrae are present in this genus,

1325-442: 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

1378-438: The crest on the lateral surface. The area in front of this furrow forms part of the middle meatus of the nose. The area behind it articulates with the ethmoid , and completes some of the anterior ethmoidal cells . Of the four borders: The lacrimal is ossified from a single center, which appears about the twelfth week in the membrane covering the cartilaginous nasal capsule. The lacrimal articulates with four bones: two of

1431-440: The dorsal border of the antorbital fenestra is formed by the maxilla , nasal , and lacrimal , but with the majority of the border formed by the nasal; there is no participation of jugal in the margin of the antorbital fenestra; a short diastema is present in the anterior tip of the dentary ; dentary teeth have a concave labial surface and a convex lingual surface (this condition is present for all except six anterior teeth);

1484-446: 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

1537-727: 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,

1590-415: The lack of prominent hypapophyses in the anterior dorsal vertebrae ; the anterior caudal centra have an oval cross section and the articular facet is as tall as it is wide; the presence of weakly curved manual unguals with weak flexor tubercles positioned ventral to the articular facet; the ilium is shallow and elongated; the ridge bounding the cuppedicus fossa is confluent with acetabular rim; and there

1643-427: The lacrimal bone usually defines the anterior rim of the orbit (eye socket), and the posterior rim of the antorbital fenestra . In some theropods (e.g. Allosaurus , Ceratosaurus , Albertosaurus ) the upper part of the lacrimal bone grew in such a manner as to form a horn on the top of the dinosaur's head, usually situated above, and anterior to the eye. In many dinosaurs, the lacrimal bone comes into contact with

Jianchangosaurus - Misplaced Pages Continue

1696-426: The lacrimal bones function in the process of lacrimation . Specifically, the lacrimal bones help form the nasolacrimal canal necessary for tear translocation. A depression on the anterior inferior portion of one bone, the lacrimal fossa , houses the membranous lacrimal sac . Tears, from the lacrimal glands , collect in this sac during excessive lacrimation. The fluid then flows through the nasolacrimal duct and into

1749-417: The lacrimal part of the orbicularis oculi and ends below in a small, hook-like projection, the lacrimal hamulus , which articulates with the lacrimal tubercle of the maxilla , and completes the upper orifice of the nasolacrimal canal ; the hamulus sometimes exists as a separate piece, and is then called the lesser lacrimal bone . The medial or nasal surface presents a longitudinal furrow, corresponding to

1802-628: 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,

1855-462: 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. Lacrimal bone The lacrimal bones are two small and fragile bones of the facial skeleton ; they are roughly the size of the little fingernail and situated at the front part of the medial wall of the orbit . They each have two surfaces and four borders. Several bony landmarks of

1908-500: The lower jaw is down-turned and in combination with the rhamphotheca on the upper jaw, functioned to pluck food. The skull measures 23 cm (230 mm) in length, and is 10% longer than the femur, a condition not shared by Beipiaosaurus . Derived features present in the skull of this genus strongly suggest adaptations for herbivory. Jianchangosaurus possesses 27 maxillary teeth and approximately 25 to 28 dentary teeth. The crowns on its teeth diminish in size as they progress toward

1961-403: 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

2014-428: 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

2067-626: The name of the county of Liaoning Province, China , where the specimen was found, and the Greek word " sauros " ( σαυρος ) meaning "lizard". The specific name yixianensis , refers to the Yixian Formation where the specimen was found, and the Latin suffix "-ensis" meaning "originating in". Jianchangosaurus was described and named by Hanyong Pu, Yoshitsugu Kobayashi , Junchang Lu , Li Xu, Yanhua Wu, Huali Chang, Jiming Zhang, and Songhai Jia in 2013 and

2120-409: The neurocranium, the frontal and ethmoid , and two of the viscerocranium, the maxilla and the inferior nasal concha . In early lobe-finned fishes and ancestral tetrapods , the lacrimal bone is a relatively large and robust bone, running from the orbit to the nostrils. It forms part of the side of the face, between the nasal bones and the maxilla. In primitive forms, it is often accompanied by

2173-497: The posterior of the skull. The teeth on the upper jaw, exhibit the conventional dental morphology - in which the surface of the tooth facing the outside of the mouth is convex. The teeth on the lower jaw possess the reversed morphology, where the surface of the tooth facing the outside is concave. Pu et al. 2013 noted that this dental morphology "likely maximized the biting stress during occlusion to cut fibers of plant material, similar to ornithopods and ceratopsians". The impressions of

Jianchangosaurus - Misplaced Pages Continue

2226-435: The primitive Falcarius and Beipiaosaurus , Jianchangosaurus was classified as a basal therizinosaur . Phylogenetic analysis suggests that it is more derived than Falcarius but more primitive than Beipiaosaurus . Jianchangosaurus is the only known therizinosaur that possesses a tail with caudal centra that are oval in shape. Left cladogram is based on the phylogenetic analysis conducted by Pu et al. 2013, showing

2279-526: 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

2332-514: The relationships of Jianchangosaurus as a very primitive therizinosaur. Right cladogram is based on Hartman et al. 2019 which has corroborated the position of Jianchangosaurus : Falcarius Jianchangosaurus Beipiaosaurus Alxasaurus Therizinosauridae Falcarius Jianchangosaurus Beipiaosaurus " Chilantaisaurus " zheziangensis Enigmosaurus Alxasaurus Therizinosauridae [REDACTED] [REDACTED] Genus The composition of

2385-466: 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

2438-408: 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

2491-497: 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,

2544-412: 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

2597-403: 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

2650-412: The upper jaw the premaxilla is edentulous and they hypothesized that it was covered by a rhamphotheca . This is also supported by the presence of a series of foramina along the buccal margin on the lateral surface of the premaxilla. By comparison, in most modern birds, the rhamphotheca grows, and is shed, continuously and in some species its color varies depending on the season. The front portion of

2703-566: 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

SECTION 50

#1733085613806

2756-429: 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

2809-473: Was 1 m (3.3 ft) high at the hips. The holotype specimen, 41HIII-0308A , was discovered on the Yixian Formation of Jianchang County , in the western part of Liaoning Province and purchased by the Henan Geological Museum noting that some of the elements were repositioned during its preparation. The genus name Jianchangosaurus , means "Jianchang lizard", and is derived from "Jianchang",

#805194