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58-653: Bagaceratops (meaning "small-horned face") is a genus of small protoceratopsid dinosaurs that lived in Asia during the Late Cretaceous , around 72 to 71 million years ago. Bagaceratops remains have been reported from the Barun Goyot Formation and Bayan Mandahu Formation . One specimen may argue the possible presence of Bagaceratops in the Djadochta Formation . Bagaceratops

116-472: A combination of basal (primitive) and derived (advanced) traits. Bagaceratops was a small-sized protoceratopsid, reaching adult dimensions of about 1–1.5 m (3.3–4.9 ft) in length and 22.7–45 kg (50–99 lb) in body mass based on Maginostris . It had a smaller frill, about ten grinding teeth per jaw, and more triangular skull than its close relative, Protoceratops . Although both Bagaceratops and Protoceratops were very similar (mostly in

174-651: 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

232-628: 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,

290-568: A nearly complete skull lacking the frill region of a large individual and was collected during expeditions led by the Sino-Canadian Dinosaur Project. In 2006 Mackoviky regarded all of these ceratopsians as junior synonyms of Bagaceratops based on the reasoning that all exhibit anatomical traits already seen on other specimens of this protoceratopsid, and some of them are likely products of preservation. In 2008 Alifanov described and named another ceratopsian taxon from

348-409: 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

406-427: 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. ;

464-455: 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

522-515: A variety of squamates and mammals, and nanhsiungchelyids turtles . 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 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

580-612: 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

638-454: Is known. This formation is mostly characterized by series of red beds , mostly light-coloured sands (yellowish, grey-brown, and rarely reddish) that are locally cemented. Sandy claystones (often red-coloured), siltstones , conglomerates , and large-scale trough cross-stratification in sands are also common across the unit. In addition, structureless, medium-grained, fine-grained and very fine-grained sandstones predominate in sediments of

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696-754: Is likely that sediments at Bayan Mandahu were deposited by short-lived rivers and lakes on an alluvial plain with a combination of dune field paleoenvironments, under a semi-arid climate. The formation is known for its vertebrate fossils in life-like poses, most of which are preserved in unstructured sandstone, indicating a catastrophic rapid burial. This formation has produced numerous dinosaurs , such as closely related protoceratopsid Protoceratops ; ankylosaurid Pinacosaurus ; alvarezsaurid Linhenykus ; dromaeosaurids Linheraptor and Velociraptor ; oviraptorids Machairasaurus and Wulatelong ; and troodontids Linhevenator , Papiliovenator , and Philovenator . Other paleofauna from this unit comprises

754-628: Is not specific to a particular depositional environment . However, the favourable conditions for diagenetic red bed formation i.e. positive Eh and neutral-alkaline pH are most commonly found in hot, semi-arid areas, and this is why red beds are traditionally associated with such climates. Secondary red beds are characterized by irregular color zonation, often related to sub- unconformity weathering profiles. The color boundaries may cross-cut lithological contacts and show more intense reddening adjacent to unconformities. Secondary reddening phases might be superimposed on earlier formed primary red beds in

812-460: 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,

870-486: Is the intrastratal alteration of ferromagnesian silicates by oxygenated groundwaters during burial. Walker's studies show that the hydrolysis of hornblende and other iron-bearing detritus follows Goldich dissolution series . This is controlled by the Gibbs free energy of the particular reaction. For example, the most easily altered material would be olivine : e.g. A key feature of this process, and exemplified by

928-474: 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

986-489: Is the relative scarcity of red-colored source sediments of suitable age close to an area of red-bed sediments in Cheshire , England. Primary red beds may also form by in situ (early diagenetic ) reddening of the sediment by the dehydration of brown or drab colored ferric hydroxides. These ferric hydroxides commonly include goethite (FeO-OH) and so-called "amorphous ferric hydroxide" or limonite . Much of this material may be

1044-621: 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

1102-824: 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;

1160-473: The large titanosaur Quaesitosaurus , and a wide diversity of mammals and squamates . The Bayan Mandahu Formation , which yielded Magnirostris (now synonym of Bagaceratops ), is considered to be Late Cretaceous in age, roughly Campanian . The dominant lithology is reddish-brown, poorly cemented, fine grained sandstone with some conglomerate, and caliche . Other facies include alluvial ( stream -deposited) and aeolian ( wind -deposited) sediments. It

1218-419: 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 ,

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1276-404: 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,

1334-639: The red beds of the Hermiin Tsav locality. He also coined the family Bagaceratopidae in order to contain these new taxa and Bagaceratops . Also during 2003, You Hailu and Dong Zhiming described and named the new genus and species of protoceratopsid Magnirostris dodsoni from red beds at the Bayan Mandahu locality of the Bayan Mandahu Formation , Inner Mongolia ( China ). The holotype of Magnirostris , IVPP V12513, represents

1392-668: The Barun Goyot Formation, Gobiceratops minitus . Its holotype (PIN 3142/299) is represented by a very small and juvenile skull that was collected from the Hermiin Tsav locality near the end of the 1970s by the Joint Soviet–Mongolian Paleontological Expedition. Though Alifanov used this skull to erect the new Gobiceratops , it had already been displayed for several years at the Moscow Paleontological Museum under

1450-826: The Barun Goyot Formation. The sediments of this formation were deposited in alluvial plain (flat land consisting of sediments deposited by highland rivers ), lacustrine , and aeolian paleoenvironments, under relatively arid to semiarid climates . Bagaceratops is the most common taxon across the Barun Goyot Formation, which was also home to many other vertebrates , including the ankylosaurids Saichania , Tarchia and Zaraapelta ; alvarezsaurids Khulsanurus and Parvicursor ; birds Gobipipus , Gobipteryx and Hollanda ; fellow protoceratopsid Breviceratops ; dromaeosaurids Kuru and Shri ; halszkaraptorine Hulsanpes ; pachycephalosaurid Tylocephale ; and oviraptorids Conchoraptor , Heyuannia and Nemegtomaia . Other taxa are represented by

1508-583: The Cretaceous Period, which ended roughly 66 million years ago. In 2019 Czepiński analyzed a vast majority of referred specimens to the ceratopsians Bagaceratops and Breviceratops , and concluded that most were in fact specimens of the former. Although the genera Gobiceratops , Lamaceratops , Magnirostris , and Platyceratops , were long considered valid and distinct taxa, and sometimes placed within Protoceratopsidae, Czepiński found

1566-561: The Japan-Mongolia Joint Paleontological Expedition collected an articulated and nearly complete Bagaceratops skeleton (MPC-D 100/535) from the Barun Goyot Formation at the Hermiin Tsav locality. In 2010 and 2011 this specimen was examined to analyze several borings (tunnel-like holes) left by invertebrae scavengers on joint areas. As of 2019, MPC-D 100/535 remains largely undescribed. In 2019 a partial skeleton (specimen KID 196) of Bagaceratops

1624-684: The Udyn Sayr and Zamyn Khond localities, respectively, of the Djadochta Formation , and evaluated the implications of these specimens for correlation of fossil sites of the latter formation. He considered one of these specimens in particular, MPC-D 100/551B, as a potential evidence of an anagenetic transition from Protoceratops andrewsi to Bagaceratops rozhdestvenskyi . Juvenile remains, at first tentatively named Protoceratops kozlowskii , and then renamed Breviceratops kozlowskii by Kurzanov in 1990, were considered to be juvenile Bagaceratops . Paul Sereno in 2000 explained this by extrapolating that

1682-442: 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

1740-405: The derived-most one. Below are the proposed phylogenetic relationships within Protoceratopsidae by Czepiński: Protoceratops andrewsi Protoceratops hellenikorhinus Breviceratops Bagaceratops The Barun Goyot Formation , based on sediments , is regarded as Late Cretaceous in age (Middle-Upper Campanian ) and has virtually yielded the bulk of material for which Bagaceratops

1798-474: The diagnostic features used to distinguish these taxa to be largely present in Bagaceratops and thus becoming synonyms of this genus. Under this reasoning, Protoceratopsidae consists of Bagaceratops , Breviceratops , and Protoceratops . Based on cranial characters such as presence or absence of premaxillary teeth and an antorbital fenestra, P. andrewsi is the basal-most protoceratopsid and Bagaceratops

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1856-420: The expedition's leading scientists, namely Polish paleontologists Teresa Maryańska and Halszka Osmólska , published a large monograph dedicated to describe this material where they named the new genus and type species of protoceratopsid Bagaceratops rozhdestvenskyi . The selected holotype is ZPAL MgD-I/126 , which consists of a relatively medium-sized skull, and a vast majority of the specimens collected by

1914-544: The expeditions were assigned to Bagaceratops , including juvenile and sub-adult skulls. The generic name, Bagaceratops , means "small-horned face" and is derived from the Mongolian baga = meaning small; and Greek ceratops = meaning horn face. The specific name, B. rozhdestvenskyi , is named in honor of the Russian paleontologist Anatoly Konstantinovich Rozhdestvensky for his notorious work on dinosaurs. In 1993,

1972-446: 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

2030-737: 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,

2088-543: The juvenile Breviceratops would grow into a mature Bagaceratops . In 2003 Russian paleontologist Vladimir R. Alifanov named the new taxa Lamaceratops tereschenkoi and Platyceratops tatarinovi from the Barun Goyot Formation. Material assigned by Alifanov corresponds to the holotype of Lamaceratops (PIN 4487/26; a partial small-sized skull), recovered from the Khulsan locality, and the holotype of Platyceratops (PIN 3142/4; an almost complete medium-sized skull), found in

2146-633: 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,

2204-585: 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. Red beds Red beds (or redbeds ) are sedimentary rocks , typically consisting of sandstone , siltstone , and shale , that are predominantly red in color due to the presence of ferric oxides . Frequently, these red-colored sedimentary strata locally contain thin beds of conglomerate , marl , limestone , or some combination of these sedimentary rocks. The ferric oxides, which are responsible for

2262-423: The mineral ferrihydrite (Fe 2 O 3 H 2 O). This dehydration or "aging" process has been found to be intimately associated with pedogenesis in alluvial floodplains and desert environments. Goethite (ferric hydroxide) is normally unstable relative to hematite and, in the absence of water or at elevated temperature, will readily dehydrate according to the reaction: The Gibbs free energy (G) for

2320-403: 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

2378-486: The name Bagaceratops rozhdestvenskyi . A comprehensive study on the intraspecific variation in morphology of B. rozhdestvenskyi was conducted by Polish paleontologist Łukasz Czepiński in 2019 , where he concluded that the previously named Gobiceratops minutus , Lamaceratops tereschenkoi , Platyceratops tatarinovi and Magnirostris dodsoni represent additional specimens and growth stages of B. rozhdestvenskyi and therefore, junior synonyms. Czepiński reexamined many of

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2436-428: 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

2494-503: The postcranial skeleton), the former had a much derived (advanced) skull morphology. Bagaceratops lacked primitive premaxillary teeth, had paired (fused) nasal bones, and an oval-shaped fenestra (hole) was developed in the maxilla —otherwise known as accessory antorbital fenestra . Bagaceratops belonged to Ceratopsia , a group of herbivorous dinosaurs with parrot -like beaks which thrived in North America and Asia during

2552-541: 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

2610-521: The reaction goethite → hematite (at 250 °C) is −2.76 kJ/mol and G becomes increasingly negative with smaller particle size. Thus detrital ferric hydroxides, including goethite and ferrihydrite, will spontaneously transform into red-colored hematite pigment with time. This process not only accounts for the progressive reddening of alluvium but also the fact that older desert dune sands are more intensely reddened than their younger equivalents. Red beds may form during diagenesis . The key to this mechanism

2668-425: The reaction, is the production of a suite of by-products which are precipitated as authigenic phases. These include mixed layer clays ( illite – montmorillonite ), quartz , potassium feldspar and carbonates as well as the pigmentary ferric oxides . Reddening progresses as the diagenetic alteration becomes more advanced, and is thus a time-dependent mechanism. The other implication is that reddening of this type

2726-540: The red color of red beds, typically occur as a coating on the grains of sediments comprising red beds. Classic examples of red beds are the Permian and Triassic strata of the western United States and the Devonian Old Red Sandstone facies of Europe. Primary red beds may be formed by the erosion and redeposition of red soils or older red beds, but a fundamental problem with this hypothesis

2784-470: 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

2842-408: 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

2900-497: 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,

2958-449: The specimens originally described by Maryańska and Osmólska, as well as the respective holotypes of these taxa, providing evidence that all traits used to separate them are, in fact, indistinguishably present on Bagaceratops and they fall within the large intraspecific variation of this taxon. He also considered Breviceratops to be a distinct and separate genus of protoceratopsid, from both Bagaceratops and Protoceratops , as it features

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3016-412: 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

3074-403: 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

3132-648: The tip of the upper jaw). During the large field work of the Polish-Mongolian Palaeontological Expeditions in the 1970s, abundant protoceratopsid specimens were discovered on eroded surfaces of the Hermiin Tsav locality of the Barun Goyot Formation , Gobi Desert . This newly collected and rich fossil material is stored in the Institute of Paleobiology of the Polish Academy of Sciences ( Poland ). In 1975, two of

3190-576: 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

3248-429: 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

3306-479: Was among the smallest ceratopsians, growing up to 1–1.5 m (3.3–4.9 ft) in length, with a weight about 22.7–45 kg (50–99 lb). Although emerging late in the reign of the dinosaurs, Bagaceratops had a fairly primitive anatomy—when compared to the much derived ceratopsids —and kept the small body size that characterized early ceratopsians. Unlike its close relative, Protoceratops , Bagaceratops lacked premaxillary teeth (cylindrical, blunt teeth near

3364-509: Was described by Bitnara Kim and colleagues, who noted no significant differences between the skeleton of Protoceratops and the former, with the exception of the anatomy of the skull and the shape and location of the clavicles . This specimen was discovered in 2007 also from the Hermiin Tsav locality of the Barun Goyot Formation, and includes a partially preserved skull with partial skeleton of an adult individual. In 2020, Czepiński described new specimens of Bagaceratops and Protoceratops from

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