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50-461: Thecodontosaurus ("socket-tooth lizard") is a genus of herbivorous basal sauropodomorph dinosaur that lived during the late Triassic period ( Rhaetian age). Its remains are known mostly from Triassic "fissure fillings" in South England . Thecodontosaurus was a small bipedal animal, about 2 m (6.5 ft) long. It is one of the first dinosaurs to be discovered and is one of

100-557: 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 ,

150-523: A career as an actuary. In the late 1850s, he studied English and mathematics at the Working Men's College and served as a secretary for the college's museum. He also worked in the library of the British Museum, where Samuel Pickworth Woodward encouraged him to study geology. In 1859, Seeley began studies at Sidney Sussex College, Cambridge , and worked as an assistant for Adam Sedgwick at

200-651: 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

250-628: 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,

300-707: A lower jaw, fell victim to heavy World War II bombings. Many remains of this dinosaur and other material related to it were destroyed in November 1940 during the Bristol Blitz . However, most bones were salvaged: today 184 fossil bones are part of the collection of the Bristol City Museum and Art Gallery . Later, more remains were found near Bristol at Tytherington . Currently about 245 fragmentary specimens are known, representing numerous individuals. In 1985, Peter Galton designated another lower jaw,

350-505: A means of escaping predators. [REDACTED] Data related to Thecodontosaurus at Wikispecies [REDACTED] [REDACTED] [REDACTED] [REDACTED] [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

400-606: A member of the Squamata , the group containing lizards and snakes. This did not change when Richard Owen coined the term Dinosauria in 1842, because Owen did not recognise Thecodontosaurus as a dinosaur; in 1865, he assigned it to the Thecodontia . It was not until 1870 that Thomas Huxley became the first person to understand that it was a dinosaur, though referring it incorrectly to the Scelidosauridae . Later, it

450-409: 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

500-551: A right dentary, as the neotype , BCM 2. The remains had been found in chalkstone infillings, breccia deposited in fissures in older rocks. The age of these deposits was once estimated as old as the late Carnian , but recent studies indicate that they date from the Rhaetian . Apart from the original type species , Thecodontosaurus antiquus , Riley and Stutchbury also found some teeth of carnivorous phytosaurians that they named Palaeosaurus cylindrodon and P. platyodon . In

550-583: A separate genus. In 1891, Harry Govier Seeley named Agrosaurus macgillivrayi , assuming the remains had been collected in 1844 by the crew of HMS Fly on the northeast coast of Australia . It was long considered the first dinosaur found in Australia, but in 1999 it was discovered that the bones probably belonged to a lot sent by Riley and Stutchbury to the British Museum of Natural History and then mislabelled. In 1906, von Huene had already noted

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600-482: A taxon of uncertain validity, and considered it possible that it might represent a juvenile of Thecodontosaurus antiquus . From the fragmentary remains of Thecodontosaurus , most of the skeleton can be reconstructed, except for the front of the skull. Thecodontosaurus had a rather short neck supporting a fairly large skull with large eyes. Its jaws contained many small- to medium-sized, serrated, leaf-shaped teeth. This dinosaur's hands and feet each had five digits, and

650-427: 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. ;

700-455: 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

750-612: 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

800-460: 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,

850-474: 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

900-621: 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

950-824: 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;

1000-510: The Magnesian Conglomerate . In 1834 and 1835, they briefly reported on the finds. They provided their initial description in 1836, naming a new genus: Thecodontosaurus . The name is derived from Greek θήκή, thēkē , "socket", and οδους, odous , "tooth", a reference to the fact that the roots of the teeth were not fused with the jaw bone, as in present lizards, but positioned in separate tooth sockets. Thecodontosaurus

1050-631: The Saurischia and the Ornithischia , based on the nature of their pelvic bones and joints . He published his results in 1888, from a lecture he had delivered the previous year. Paleontologists of his time had been dividing the Dinosauria in various ways, depending on the structure of their feet and the form of their teeth. Seeley's division, however, has stood the test of time, though the birds have subsequently been found to descend, not from

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1100-620: The Woodwardian Museum . He helped curate the museum's fossil collection and began field studies on the local geology. Seeley graduated from Sidney Sussex College in 1863 and joined St John's in 1868 but never took a degree. He turned down positions both with the British Museum and the Geological Survey of Britain to work on his own. Late in his career he accepted a position as Professor of Geology at King's College, Cambridge and Bedford College (London) (1876). He

1150-404: 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,

1200-499: The "bird-hipped" Ornithischia, but from the "lizard-hipped" Saurischia. He found the two groups so distinct that he also argued for separate origins: not until the 1980s did new techniques of cladistic analysis show that both groups of dinosaurs really did have common ancestors in the Triassic . Seeley described and named numerous dinosaurs from their fossils in the course of his career. His popular book on pterosaurs , Dragons of

1250-714: The Air (1901), found that the development of birds and pterosaurs paralleled each other. His belief that they had a common origin has been proved, for both are archosaurs, just not as close as he thought. He upset Richard Owen 's characterization of the pterosaurs as cold-blooded, sluggish gliders, and recognized them as warm-blooded active fliers. He was elected a Fellow of the Royal Society in June 1879 for his work on reptiles and dinosaurs, and delivered their Croonian Lecture in 1887. ... he will be best remembered, perhaps, for

1300-473: 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

1350-442: 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

1400-498: The close resemblance and renamed the species Thecodontosaurus macgillivrayi . It is thus a junior synonym of Thecodontosaurus antiquus . Presently, the only valid species is thus T. antiquus . Thecodontosaurus caducus was named by Adam Yates in 2003 for a juvenile specimen found in Wales ; in 2007 this was made the separate genus Pantydraco . However, Ballell, Rayfield & Benton (2020) considered Pantydraco caducus to be

1450-564: The existence of a robust morph in the population, seen by him as a possible second species or, more likely, an instance of sexual dimorphism . Benton also indicated some unique derived traits, or autapomorphies , for the species: a long basipterygoid process on the braincase ; a dentary that is short in relation to the total length of the lower jaw; an ilium that has a back end that is subquadrate instead of rounded. The small size has been explained as an instance of insular dwarfism . Riley and Stutchbury originally saw Thecodontosaurus as

1500-446: 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

1550-737: 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,

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1600-450: The hands were long and rather narrow, with an extended claw on each. This dinosaur's front limbs were much shorter than the legs, and its tail was much longer than the head, neck and body put together. On average, it was 1.2 metres (3.9 ft) long, 30 centimetres (12 in) or 1 ft. tall, and weighed 11 kilograms (24 lb). The largest individuals had an estimated length of 2.5 metres (8.2 ft). In 2000, Michael Benton noted

1650-432: 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

1700-633: 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,

1750-544: The late nineteenth century, the theory became popular that such remains belonged to carnivorous prosauropods : animals with the body of Thecodontosaurus , but with slicing teeth. In 1890, Arthur Smith Woodward accordingly named a Thecodontosaurus platyodon, and in 1908 Friedrich von Huene named a Thecodontosaurus cylindrodon . Though still defended by Michael Cooper in 1981, the hypothesis that such creatures existed has now been totally discredited. On one occasion, material of Thecodontosaurus was, by mistake, described as

1800-498: 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. Harry Govier Seeley Harry Govier Seeley (18 February 1839 – 8 January 1909) was a British paleontologist . Seeley was born in London on 18 February 1839, the second son of Richard Hovill Seeley, a goldsmith, and his second wife Mary Govier. When his father

1850-403: 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

1900-428: 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

1950-478: The oldest that existed. Many species have been named in the genus, but only the type species Thecodontosaurus antiquus is seen as valid today. In the autumn of 1834, surgeon Henry Riley (1797–1848) and the curator of the Bristol Institution , Samuel Stutchbury , began to excavate "saurian remains" at the quarry of Durdham Down , at Clifton , presently a part of Bristol , which is part of

2000-426: The prosauropod-sauropod split. Examination of Thecodontosaurus revealed it was exclusively bipedal. Studies of the muscle attachments in its fore and hindlimbs suggest that it was an extremely fast bipedal runner that relied on its weaker front limbs for grasping vegetation, cutting it up and feeding it into its mouth. Its advanced running capabilities suggest it was well adapted for high-speed sprinting, probably as

2050-541: 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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2100-497: 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,

2150-412: 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

2200-403: 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

2250-576: 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

2300-429: 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

2350-489: Was declared bankrupt, Seeley was sent to live with a family of piano makers. Between the ages of eleven and fourteen, he went to a day school and then spent the next two years learning to make pianos. He also attended lectures at the Royal School of Mines by Thomas Henry Huxley , Edward Forbes , and other notable scientists. In 1855, with the support of his uncle, Seeley began to study law but shortly gave it up to pursue

2400-544: Was later Lecturer on Geology and Physiology at Dulwich College and Professor of Geology and Mineralogy at King's College London (1896–1905). He died in Kensington, London and was buried in Brookwood Cemetery . He had married in 1872 Eleanora Jane, daughter of William Mitchell of Bath. Their daughter Maude married Arthur Smith Woodward , FRS. Seeley determined that dinosaurs fell into two great groups,

2450-581: Was placed in either the Anchisauridae or its own Thecodontosauridae alongside Agrosaurus . Modern exact cladistic analyses have not been conclusive. Although not actually the earliest member of the group, Thecodontosaurus is sometimes placed in a very basal position among the sauropodomorph dinosaurs. It was earlier included under the Prosauropoda , but more recently it has been suggested that Thecodontosaurus and its relatives preceded

2500-541: Was the fifth dinosaur named, after Megalosaurus , Iguanodon , Streptospondylus and Hylaeosaurus , though Riley and Stutchbury were not aware of this, the very concept of Dinosauria only being created in 1842. In 1843, in his catalogue of British fossils, John Morris provided a complete species name : Thecodontosaurus antiquus . The specific epithet , "antiquus" , means "ancient" in Latin . The original type specimen or holotype of Thecodontosaurus , BCM 1,

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