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52-543: See text The Stromboidea , originally named the Strombacea by Rafinesque in 1815, is a superfamily of medium-sized to very large sea snails in the clade Littorinimorpha . Stromboideans have medium to large shells, attaining a wide variety of lengths depending on the species (20–400 mm from the smallest aporrhaids to the largest strombids ). A stromboidean shell has a medium (e.g. spider conchs, Lambis spp.) to high spire (e.g. tibias, Tibia spp.), and

104-499: A BioCode that would regulate all taxon names, but this attempt has so far failed because of firmly entrenched traditions in each community. Consider a particular species, the red fox , Vulpes vulpes : in the context of the Zoological Code , the specific epithet vulpes (small v ) identifies a particular species in the genus Vulpes (capital V ) which comprises all the "true" foxes. Their close relatives are all in

156-420: A "hybrid formula" that specifies the parentage, or may be given a name. For hybrids receiving a hybrid name , the same ranks apply, prefixed with notho (Greek: 'bastard'), with nothogenus as the highest permitted rank. If a different term for the rank was used in an old publication, but the intention is clear, botanical nomenclature specifies certain substitutions: Classifications of five species follow:

208-585: A 1 mm mesh also depends upon whether it is alive or dead at the time of sorting. Mesofauna are macroscopic soil animals such as arthropods or nematodes . Mesofauna are extremely diverse; considering just the springtails ( Collembola ), as of 1998, approximately 6,500 species had been identified. Microfauna are microscopic or very small animals (usually including protozoans and very small animals such as rotifers ). To qualify as microfauna, an organism must exhibit animal-like characteristics, as opposed to microflora , which are more plant-like. Stygofauna

260-567: A fast evolutionary radiation that occurred long ago, such as the main taxa of placental mammals . In his landmark publications, such as the Systema Naturae , Carl Linnaeus used a ranking scale limited to kingdom, class, order, genus, species, and one rank below species. Today, the nomenclature is regulated by the nomenclature codes . There are seven main taxonomic ranks: kingdom, phylum or division, class, order, family, genus, and species. In addition, domain (proposed by Carl Woese )

312-453: A group of organisms by their size, larger than microfauna but smaller than macrofauna, rather than a taxonomic grouping. One environment for meiofauna is between grains of damp sand (see Mystacocarida ). In practice these are metazoan animals that can pass unharmed through a 0.5–1 mm mesh but will be retained by a 30–45 μm mesh, but the exact dimensions will vary from researcher to researcher. Whether an organism passes through

364-638: A lower level may be denoted by adding the prefix " infra ", meaning lower , to the rank. For example, infra order (below suborder) or infra family (below subfamily). Botanical ranks categorize organisms based (often) on their relationships ( monophyly is not required by that clade, which does not even mention this word, nor that of " clade "). They start with Kingdom, then move to Division (or Phylum), Class, Order, Family, Genus, and Species. Taxa at each rank generally possess shared characteristics and evolutionary history. Understanding these ranks aids in taxonomy and studying biodiversity. There are definitions of

416-399: A new rank at will, at any time, if they feel this is necessary. In doing so, there are some restrictions, which will vary with the nomenclature code that applies. The following is an artificial synthesis, solely for purposes of demonstration of absolute rank (but see notes), from most general to most specific: Ranks are assigned based on subjective dissimilarity, and do not fully reflect

468-459: A particular organism, it is usually not necessary to specify names at ranks other than these first two, within a set of taxa covered by a given rank-based code. However, this is not true globally because most rank-based codes are independent from each other, so there are many inter-code homonyms (the same name used for different organisms, often for an animal and for a taxon covered by the botanical code). For this reason, attempts were made at creating

520-576: A taxon in a category above the species level). It should be a natural group (that is, non-artificial, non- polyphyletic ), as judged by a biologist, using all the information available to them. Equally ranked higher taxa in different phyla are not necessarily equivalent in terms of time of origin, phenotypic distinctiveness or number of lower-ranking included taxa (e.g., it is incorrect to assume that families of insects are in some way evolutionarily comparable to families of mollusks). Of all criteria that have been advocated to rank taxa, age of origin has been

572-436: A thickened and frequently expanded outer lip (e.g. the queen conch, Lobatus gigas , or the goliath conch, Lobatus goliath ) that may be ornamented by long spines (e.g. the spider conch, Lambis chiragra , common pelican foot, Aporrhais spp.) or digitations (e.g. the millipede spider conch, Lambis millepeda ). The anterior portion of the outer lip may present a stromboid notch , an indentation through which one of

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624-564: Is also called a binomial , that is, a two-term name. For example, the zoological name for the human species is Homo sapiens . This is usually italicized in print or underlined when italics are not available. In this case, Homo is the generic name and it is capitalized; sapiens indicates the species and it is not capitalized. While not always used, some species include a subspecific epithet. For instance, modern humans are Homo sapiens sapiens , or H. sapiens sapiens . In zoological nomenclature, higher taxon names are normally not italicized, but

676-408: Is any fauna that lives in groundwater systems or aquifers, such as caves , fissures and vugs . Stygofauna and troglofauna are the two types of subterranean fauna (based on life-history). Both are associated with subterranean environments – stygofauna is associated with water, and troglofauna with caves and spaces above the water table . Stygofauna can live within freshwater aquifers and within

728-494: Is associated with caves and spaces above the water table and stygofauna with water. Troglofaunal species include spiders , insects , myriapods and others. Some troglofauna live permanently underground and cannot survive outside the cave environment. Troglofauna adaptations and characteristics include a heightened sense of hearing, touch and smell. Loss of under-used senses is apparent in the lack of pigmentation as well as eyesight in most troglofauna. Troglofauna insects may exhibit

780-467: Is not a requirement of the zoological and botanical codes. A classification in which all taxa have formal ranks cannot adequately reflect knowledge about phylogeny. Since taxon names are dependent on ranks in rank-based (Linnaean) nomenclature, taxa without ranks cannot be given names. Alternative approaches, such as phylogenetic nomenclature , as implemented under the PhyloCode and supported by

832-435: Is now widely used as a fundamental rank, although it is not mentioned in any of the nomenclature codes, and is a synonym for dominion ( Latin : dominium ), introduced by Moore in 1974. A taxon is usually assigned a rank when it is given its formal name. The basic ranks are species and genus. When an organism is given a species name it is assigned to a genus, and the genus name is part of the species name. The species name

884-431: Is usually associated with a certain body plan , which is also, however, an arbitrary criterion. Enigmatic taxa are taxonomic groups whose broader relationships are unknown or undefined. (See Incertae sedis .) There are several acronyms intended to help memorise the taxonomic hierarchy, such as "King Phillip came over for great spaghetti". (See taxonomy mnemonic .) Epifaunal Fauna comes from

936-789: The Botanical Code , the Prokaryotic Code , the Code for Viruses , the draft BioCode and the PhyloCode all recommend italicizing all taxon names (of all ranks). There are rules applying to the following taxonomic ranks in the International Code of Zoological Nomenclature : superfamily, family, subfamily, tribe, subtribe, genus, subgenus, species, subspecies. The International Code of Zoological Nomenclature divides names into "family-group names", "genus-group names" and "species-group names". The Code explicitly mentions

988-483: The International Society for Phylogenetic Nomenclature , or using circumscriptional names , avoid this problem. The theoretical difficulty with superimposing taxonomic ranks over evolutionary trees is manifested as the boundary paradox which may be illustrated by Darwinian evolutionary models. There are no rules for how many species should make a genus, a family, or any other higher taxon (that is,

1040-427: The fruit fly familiar in genetics laboratories ( Drosophila melanogaster ), humans ( Homo sapiens ), the peas used by Gregor Mendel in his discovery of genetics ( Pisum sativum ), the "fly agaric" mushroom Amanita muscaria , and the bacterium Escherichia coli . The eight major ranks are given in bold; a selection of minor ranks are given as well. Taxa above the genus level are often given names based on

1092-520: The pore spaces of limestone , calcrete or laterite , whilst larger animals can be found in cave waters and wells. Stygofaunal animals, like troglofauna, are divided into three groups based on their life history - stygophiles, stygoxenes, and stygobites. Troglofauna are small cave -dwelling animals that have adapted to their dark surroundings. Troglofauna and stygofauna are the two types of subterranean fauna (based on life-history). Both are associated with subterranean environments – troglofauna

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1144-418: The type genus , with a standard termination. The terminations used in forming these names depend on the kingdom (and sometimes the phylum and class) as set out in the table below. Pronunciations given are the most Anglicized . More Latinate pronunciations are also common, particularly / ɑː / rather than / eɪ / for stressed a . There is an indeterminate number of ranks, as a taxonomist may invent

1196-633: The American Ornithologists' Union published in 1886 states "No one appears to have suspected, in 1842 [when the Strickland code was drafted], that the Linnaean system was not the permanent heritage of science, or that in a few years a theory of evolution was to sap its very foundations, by radically changing men's conceptions of those things to which names were to be furnished." Such ranks are used simply because they are required by

1248-556: The Stromboidea have been addressed in 2005, by Simone. The author proposed a cladogram (a tree of descent) based on an extensive morpho - anatomical analysis of representatives of Aporrhaidae , Strombidae, Xenophoridae and Struthiolariidae . In his analysis, Simone recognized Strombidae as a monophyletic taxon supported by 13 synapomorphies (traits that are shared by two or more taxa and their most recent common ancestor ), with at least eight distinct genera. He considered

1300-497: The animal's long eyestalks may protrude. The shell morphology of some stromboideans (e.g. Lobatus gigas ) is not solely determined by the animal's genes; environmental conditions such as location, diet, temperature and depth, and biological interactions such as predation, can greatly affect it. Juvenile individuals of some species develop heavier shells when exposed to predators. They also develop wider and thicker shells with fewer but longer spines in deeper water. This superfamily

1352-419: The animal's mouth, where they are finally ingested. Taxonomic rank In biology , taxonomic rank (which some authors prefer to call nomenclatural rank because ranking is part of nomenclature rather than taxonomy proper, according to some definitions of these terms) is the relative or absolute level of a group of organisms (a taxon ) in a hierarchy that reflects evolutionary relationships. Thus,

1404-432: The family Canidae , which includes dogs, wolves, jackals, and all foxes; the next higher major taxon, Carnivora (considered an order), includes caniforms (bears, seals, weasels, skunks, raccoons and all those mentioned above), and feliforms (cats, civets, hyenas, mongooses). Carnivorans are one group of the hairy, warm-blooded, nursing members of the class Mammalia , which are classified among animals with notochords in

1456-599: The following ranks for these categories: The rules in the Code apply to the ranks of superfamily to subspecies, and only to some extent to those above the rank of superfamily. Among "genus-group names" and "species-group names" no further ranks are officially allowed, which creates problems when naming taxa in these groups in speciose clades, such as Rana . Zoologists sometimes use additional terms such as species group , species subgroup , species complex and superspecies for convenience as extra, but unofficial, ranks between

1508-464: The following taxonomic categories in the International Code of Nomenclature for Cultivated Plants : cultivar group , cultivar , grex . The rules in the ICN apply primarily to the ranks of family and below, and only to some extent to those above the rank of family. (See also descriptive botanical name .) Taxa at the rank of genus and above have a botanical name in one part (unitary name); those at

1560-407: The fossil record and include lingulata , trilobites and worms . They made burrows in the sediment as protection and may also have fed upon detritus or the mat of microbes which tended to grow on the surface of the sediment. Today, a variety of organisms live in and disturb the sediment . The deepest burrowers are the ghost shrimps ( Thalassinidea ), which go as deep as 3 metres (10 ft) into

1612-489: The genus Terebellum as the most basal taxon , distinguished from the remaining strombids by 13 synapomorphies, including a rounded foot. Though the genus Tibia was left out of the analysis, Simone regarded it as probably closely related to Terebellum , apparently due to some well known morphological similarities between them. Stromboideans are exclusively marine, and most species inhabit shallow waters. Adult individuals may be epifaunal , remaining partially buried in

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1664-480: The gradational nature of variation within nature. These problems were already identified by Willi Hennig , who advocated dropping them in 1969, and this position gathered support from Graham C. D. Griffiths only a few years later. In fact, these ranks were proposed in a fixist context and the advent of evolution sapped the foundations of this system, as was recognised long ago; the introduction of The Code of Nomenclature and Check-list of North American Birds Adopted by

1716-434: The hierarchy of taxa (hence, their ranks) does not necessarily reflect the hierarchy of clades . While older approaches to taxonomic classification were phenomenological, forming groups on the basis of similarities in appearance, organic structure and behavior, two important new methods developed in the second half of the 20th century changed drastically taxonomic practice. One is the advent of cladistics , which stemmed from

1768-405: The most basic (or important) is the species, but this opinion is not universally shared. Thus, species are not necessarily more sharply defined than taxa at any other rank, and in fact, given the phenotypic gaps created by extinction, in practice, the reverse is often the case. Ideally, a taxon is intended to represent a clade , that is, the phylogeny of the organisms under discussion, but this

1820-409: The most frequently advocated. Willi Hennig proposed it in 1966, but he concluded in 1969 that this system was unworkable and suggested dropping absolute ranks. However, the idea of ranking taxa using the age of origin (either as the sole criterion, or as one of the main ones) persists under the name of time banding, and is still advocated by several authors. For animals, at least the phylum rank

1872-492: The most inclusive clades (such as Eukarya and Opisthokonta ) have the highest ranks, whereas the least inclusive ones (such as Homo sapiens or Bufo bufo ) have the lowest ranks. Ranks can be either relative and be denoted by an indented taxonomy in which the level of indentation reflects the rank, or absolute, in which various terms, such as species , genus , family , order , class , phylum , kingdom , and domain designate rank. This page emphasizes absolute ranks and

1924-577: The name Fauna , a Roman goddess of earth and fertility, the Roman god Faunus , and the related forest spirits called Fauns . All three words are cognates of the name of the Greek god Pan , and panis is the Modern Greek equivalent of fauna (πανίς or rather πανίδα). Fauna is also the word for a book that catalogues the animals in such a manner. The term was first used by Carl Linnaeus from Sweden in

1976-479: The phylum Chordata , and with them among all animals in the kingdom Animalia . Finally, at the highest rank all of these are grouped together with all other organisms possessing cell nuclei in the domain Eukarya . The International Code of Zoological Nomenclature defines rank as: "The level, for nomenclatural purposes, of a taxon in a taxonomic hierarchy (e.g. all families are for nomenclatural purposes at

2028-455: The rank of species and above (but below genus) have a botanical name in two parts ( binary name ); all taxa below the rank of species have a botanical name in three parts (an infraspecific name ). To indicate the rank of the infraspecific name, a "connecting term" is needed. Thus Poa secunda subsp. juncifolia , where "subsp". is an abbreviation for "subspecies", is the name of a subspecies of Poa secunda . Hybrids can be specified either by

2080-828: The rank-based codes (the Zoological Code , the Botanical Code , the Code for Cultivated Plants , the Prokaryotic Code , and the Code for Viruses ) require them. However, absolute ranks are not required in all nomenclatural systems for taxonomists; for instance, the PhyloCode , the code of phylogenetic nomenclature , does not require absolute ranks. Taxa are hierarchical groups of organisms, and their ranks describes their position in this hierarchy. High-ranking taxa (e.g. those considered to be domains or kingdoms, for instance) include more sub-taxa than low-ranking taxa (e.g. those considered genera, species or subspecies). The rank of these taxa reflects inheritance of traits or molecular features from common ancestors. The name of any species and genus are basic ; which means that to identify

2132-653: The rank-based codes; because of this, some systematists prefer to call them nomenclatural ranks . In most cases, higher taxonomic groupings arise further back in time, simply because the most inclusive taxa necessarily appeared first. Furthermore, the diversity in some major taxa (such as vertebrates and angiosperms ) is better known that that of others (such as fungi , arthropods and nematodes ) not because they are more diverse than other taxa, but because they are more easily sampled and studied than other taxa, or because they attract more interest and funding for research. Of these many ranks, many systematists consider that

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2184-468: The same rank, which lies between superfamily and subfamily)." Note that the discussions on this page generally assume that taxa are clades ( monophyletic groups of organisms), but this is required neither by the International Code of Zoological Nomenclature nor by the Botanical Code , and some experts on biological nomenclature do not think that this should be required, and in that case,

2236-435: The sand or never burying at all (e.g. Strombidae ), but may also be infaunal , remaining buried for most of their lifetime ( Struthiolariidae ). Herbivory is the most common feeding habit among stromboideans. Snails in the family Strombidae were widely accepted as carnivores by several authors in the 19th century, a concept that persisted until the first half of the 20th century. This erroneous idea evidently originated in

2288-615: The seafloor. Infauna are benthic organisms that live within the bottom substratum of a water body, especially within the bottom-most oceanic sediments, the layer of small particles at the bottom of a body of water, rather than on its surface. Bacteria and microalgae may also live in the interstices of bottom sediments. In general, infaunal animals become progressively smaller and less abundant with increasing water depth and distance from shore, whereas bacteria show more constancy in abundance, tending toward one million cells per milliliter of interstitial seawater. Such creatures are found in

2340-577: The sediment at the bottom of the ocean. Limnofauna refers to the animals that live in fresh water. Macrofauna are benthic or soil organisms which are retained on a 0.5 mm sieve. Studies in the deep sea define macrofauna as animals retained on a 0.3 mm sieve to account for the small size of many of the taxa. Megafauna are large animals of any particular region or time. For example, Australian megafauna . Meiofauna are small benthic invertebrates that live in both marine and freshwater environments . The term meiofauna loosely defines

2392-485: The subgenus and species levels in taxa with many species, e.g. the genus Drosophila . (Note the potentially confusing use of "species group" as both a category of ranks as well as an unofficial rank itself. For this reason, Alain Dubois has been using the alternative expressions "nominal-series", "family-series", "genus-series" and "species-series" (among others) at least since 2000. ) At higher ranks (family and above)

2444-559: The suffix -acea. According to the classification proposed by Bouchet & Rocroi (2005), the families and subfamilies in the superfamily Stromboidea are as follows. Fossil families are marked with a dagger †. Some authors consider two following families as separate families: Struthiolaria papulosa Tylospira scutulata Cuphosolenus serresianus Aporrhais occidentalis Aporrhais pespelecani Xenophora conchyliophora Onustus caribaeus Onustus indicus Strombidae ► The phylogenetic relationships among

2496-400: The title of his 1745 work Fauna Suecica . Cryofauna refers to the animals that live in, or very close to, cold areas. Cryptofauna is the fauna that exists in protected or concealed microhabitats . Epifauna, also called epibenthos , are aquatic animals that live on the bottom substratum as opposed to within it, that is, the benthic fauna that live on top of the sediment surface at

2548-423: The water. While remaining completely buried in the sand, struthiolariids are connected to the surface by two artificially produced holes. These holes are made by the animal's proboscis , held in place with mucus, and are used for inhalating and exhalating water. Feeding particles are captured as the inhaled water flows over the animal's gills, become embedded in mucus, and are moved along a ciliary tract that leads to

2600-727: The works of the German entomologist Willi Hennig . Cladistics is a method of classification of life forms according to the proportion of characteristics that they have in common (called synapomorphies ). It is assumed that the higher the proportion of characteristics that two organisms share, the more recently they both came from a common ancestor. The second one is molecular systematics, based on genetic analysis , which can provide much additional data that prove especially useful when few phenotypic characters can resolve relationships, as, for instance, in many viruses , bacteria and archaea , or to resolve relationships between taxa that arose in

2652-498: The writings of Jean-Baptiste Lamarck , who classified strombids with other supposedly carnivorous snails. This idea was subsequently repeated by other authors, but were not supported by observation. Nowadays, strombids are known to be specialized herbivores and occasional detritivores . They are usually associated with shallow water reefs and seagrass meadows . Struthiolariids are ciliary mucous feeders, obtaining their nutrition from particles and organic matter suspended in

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2704-581: Was previously known as Strombacea. Prior to the recent ruling by the ICZN , many invertebrate superfamily names ended in the suffix -acea, or -aceae, not -oidea as now required according to ICZN article 29.2. The suffix -oidea used to be used for some subclasses and superorders, where it is still found. In much of the older literature including Keen 1958, Moore and colleagues 1952, and the Treatise on Invertebrate Paleontology , gastropod superfamilies are written with

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