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45-455: Lagosuchus is an extinct genus of avemetatarsalian archosaur from the Late Triassic of Argentina . The type species of Lagosuchus , Lagosuchus talampayensis , is based on a small partial skeleton recovered from the early Carnian -age Chañares Formation . The holotype skeleton of L. talampayensis is fairly fragmentary, but it does possess some traits suggesting that Lagosuchus

90-557: A species : see Botanical name and Specific name (zoology) . The rules for the scientific names of organisms are laid down in 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 ,

135-643: 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

180-621: 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,

225-428: A new genus, Marasuchus . Marasuchus is generally considered one of the more complete early dinosauriforms, useful for estimating ancestral traits for the origin of dinosaurs. This would also render Lagosuchus a nomen dubium , simply a name referring to a fossil which is too fragmentary to have a formal genus. However, other paleontologists support the argument that Lagosuchus is a valid genus, and that Marasuchus

270-409: 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

315-456: A similar neural spine morphology, but it possesses osteoderms on its neural spines, unlike Lagosuchus and Marasuchus . The two sacral (hip) vertebrae had large and slightly tapering transverse processes. This is also the case for the first four caudal (tail) vertebrae at the base of the tail. Further back, the caudals have much shorter transverse processes and more elongated centra, like those of Marasuchus . The scapula (shoulder blade)

360-411: A strong projecting convex surface stretching up along its inner and upper portions. This trait is shared with Marasuchus and lagerpetids . The femur also possessed a knob-like anterior trochanter and a distinct fourth trochanter . The tibia and fibula were narrow and about 10% longer than the femur. Like other dinosauriforms, the tibia had a strong cnemial crest at the knee and a lateral groove near

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

495-579: Is a junior synonym of it. The type species Lagosuchus talampayensis was first described by Alfred S. Romer in 1971, who considered it a " pseudosuchian " (then a collection of various non-dinosaurian " thecodonts "). In 1972 he named a second species, Lagosuchus lilloensis , known from larger and more well-preserved specimens. A later review by Jose Bonaparte in 1975 synonymized the two species and considered Lagosuchus intermediate between "pseudosuchians" and saurischian dinosaurs. Modern authors now consider at least L. lilloensis to be firmly on

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540-596: 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

585-410: Is present in embryos, and in adult forms of some species; in most species including dinosaurs, centra are more ossified with the notochordal opening closed, improving resistance against compressional forces. Heterocoelous vertebrae allow flexibility while preventing rotation. Procoelous and opisthocoelous centra form concavo-convex ( ball and socket ) joints, where the convex end, the condyle , fits into

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

720-503: Is weakly curved and flattened sideways. It is believed that Lagosuchus and Marasuchus were transitional between cold blooded reptiles and warm blooded dinosaurs. [REDACTED] [REDACTED] [REDACTED] Genus The composition of 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

765-621: 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

810-799: 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;

855-558: The Lagosuchus holotype. The dorsal (trunk) vertebrae had centra about three times longer than tall, slightly more elongated than those referred to Marasuchus . Yet the dorsals also had many traits in common with Marasuchus , such as large excavations below the transverse processes . In addition, they both have trapezoidal neural spines with thickened upper edges which expand forwards and backwards to contact those of adjacent vertebrae. The contemporary silesaurid Lewisuchus has

900-551: The Middle Triassic . Radiometric dating in 2016 has dated the main fossiliferous section of the formation to the early Carnian stage, near the start of the Late Triassic . Lagosuchus talampayensis , in its most restricted form, can only be described based on the incomplete holotype skeleton. It was a lightly built archosaur, with long, slender legs and well-developed feet - features it shares with certain dinosaurs. With its short forelimbs, long shin bones, and narrow stance, it

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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990-469: The French botanist Joseph Pitton de Tournefort (1656–1708) is considered "the founder of the modern concept of genera". The scientific name (or 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

1035-427: The ankle. The ankle has a small distal tarsal 3, a larger distal tarsal 4, and a rounded astragalus , but the calcaneum is missing from the fossil. The middle three metatarsals are elongated, with metatarsal III as the longest. Metatarsal V is short and tapers to a sharp tip. Metatarsal I is also short, though still longer than V (unlike Marasuchus ). Phalanges are slender, and an isolated pedal ungual (toe claw)

1080-442: 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

1125-460: The concave end, the cotyle (also: cotyla ). This configuration allows for greater stability without restricting mobility. In long necks and tails, this stabilization works best when the convex part is pointing away from the body. In sauropods, vertebrae in front of the sacrum are therefore typically opisthocoelous, while those of the tail are procoelous. As a vertebral column can contain different types of central morphologies, transitional centra with

1170-446: 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

1215-727: 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,

1260-432: 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 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

1305-628: 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,

1350-434: The length of the humerus. In contrast, Marasuchus has a larger ulna with a strong olecranon process. The forelimbs in general were much smaller than the hindlimbs. The pelvis (hip) is similar to that of Marasuchus , with a thin pubis and a plate-like ischium which has a large ridge on its rear edge. The femur is elongated and has a slightly inturned femoral head. The femoral head is characteristically 'globose', with

1395-473: The lineage of archosaurs leading to dinosaurs. However, the genus Lagosuchus is regarded by some to be dubious . Paul Sereno and Andrea Arcucci considered L. talampayensis to be undiagnosable in a 1994 study, and reclassified L. lilloensis as a new genus, Marasuchus . In 2019, PULR 09, the holotype skeleton of L. talampayensis , was redescribed by Federico Agnolin and Martin Ezcurra . They argued that

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1440-431: 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. Glossary of dinosaur anatomy#dorsals This Glossary explains technical terms commonly employed in the description of dinosaur body fossils . Besides dinosaur -specific terms, it covers terms with wider usage, when these are of central importance in

1485-403: 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

1530-428: 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

1575-526: 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

1620-450: The skeleton was not only diagnostic, but indistinguishable from specimens of Marasuchus lilloensis . As a result, they supported the synonymy proposed by Bonaparte, referring specimens of Marasuchus lilloensis back to Lagosuchus talampayensis . The Chañares Formation's age has been through much debate. It has traditionally been considered to belong to the Ladinian stage, the last stage of

1665-497: 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,

1710-412: 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

1755-402: The study of dinosaurs or when their discussion in the context of dinosaurs is beneficial. The glossary does not cover ichnological and bone histological terms, nor does it cover measurements. Amphicoely is the primitive condition tetrapods. In fishes, the ends of the centra are deeply excavated and connected via a small opening, the passage for the notochord . In reptiles, this type of centrum

1800-403: 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

1845-566: 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

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1890-429: 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

1935-410: Was a probable dinosauriform , closely related to dinosaurs . A second potential species of Lagosuchus , L. lilloensis , is based on an assortment of slightly larger and more well-preserved fossils. These larger specimens have been considered much more diagnostic and informative than the original small L. talampayensis skeleton. As a result, some paleontologists have placed the larger specimens into

1980-503: Was likely an agile biped adapted for running. Gregory S. Paul inferred that Lagosuchus was one of the smallest Triassic archosaurs, with a weight of about 167 g, similar in size and ecology to a weasel or ferret . Thomas Holtz estimated that Lagosuchus could have obtained a total length of 1.7 ft (51 cm) and a weight similar to that of a pigeon (50-500 g). However, these estimates may have been based on specimens referred to Marasuchus, some of which were significantly larger than

2025-449: Was narrow, with a slightly expanded upper tip and a thick longitudinal ridge on its inner surface. The humerus was also quite narrow, with a subtriangular deltopectoral crest in its upper part. The deltopectoral crest extends about 31% down the length of the humerus, making it somewhat less extensive than that of other avemetatarsalians (including Marasuchus ). The radius and ulna are thin, simple, and unusually short, only about 65%

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