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62-480: See text Moa ( order Dinornithiformes ) are an extinct group of flightless birds formerly endemic to New Zealand . During the Late Pleistocene - Holocene , there were nine species (in six genera). The two largest species, Dinornis robustus and Dinornis novaezelandiae , reached about 3.6 metres (12 ft) in height with neck outstretched, and weighed about 230 kilograms (510 lb) while
124-583: A sister group to ratites. The nine species of moa were the only wingless birds, lacking even the vestigial wings that all other ratites have. They were the largest terrestrial animals and dominant herbivores in New Zealand's forest, shrubland, and subalpine ecosystems until the arrival of the Māori , and were hunted only by Haast's eagle . Moa extinction occurred within 100 years of human settlement of New Zealand, primarily due to overhunting. The word moa
186-401: A 1986 study, Valerius Geist claimed Bergmann's rule to be false: the correlation with temperature is spurious; instead, Geist found that body size is proportional to the duration of the annual productivity pulse, or food availability per animal during the growing season. Because many factors can affect body size, there are many critics of Bergmann's rule. Some believe that latitude itself is
248-765: A certain selectivity in the choice of gizzard stones and chose the hardest pebbles. The pairs of species of moa described as Euryapteryx curtus / E. exilis , Emeus huttonii / E. crassus , and Pachyornis septentrionalis / P. mappini have long been suggested to constitute males and females, respectively. This has been confirmed by analysis for sex-specific genetic markers of DNA extracted from bone material. For example, before 2003, three species of Dinornis were recognised: South Island giant moa ( D. robustus ), North Island giant moa ( D. novaezealandiae ), and slender moa ( D. struthioides ). However, DNA showed that all D. struthioides were males, and all D. robustus were females. Therefore,
310-454: A grinding action that allowed them to eat coarse plant material. This grinding action suggests that moa were not effective seed dispersers, with only the smallest seeds passing through their gut intact. These stones were commonly smooth rounded quartz pebbles, but stones over 110 millimetres (4 in) long have been found among preserved moa gizzard contents. Dinornis gizzards could often contain several kilograms of stones. Moa likely exercised
372-406: A large loop within the body cavity. They are the only ratites known to exhibit this feature, which is also present in several other bird groups, including swans , cranes , and guinea fowl . The feature is associated with deep resonant vocalisations that can travel long distances. The moa's closest relatives are small terrestrial South American birds called the tinamous , which can fly. Previously,
434-446: A low fecundity and a long maturation period, taking about 10 years to reach adult size. The large Dinornis species took as long to reach adult size as small moa species, and as a result, had fast skeletal growth during their juvenile years. No evidence has been found to suggest that moa were colonial nesters. Moa nesting is often inferred from accumulations of eggshell fragments in caves and rock shelters, little evidence exists of
496-425: A more detailed, species-level phylogeny, of the moa branch (Dinornithiformes) of the "ancient jawed" birds (Palaeognathae) shown above: † Megalapteryx didinus † D. robustus † D. novaezealandiae † P. australis † P. elephantopus † P. geranoides † Anomalopteryx didiformis † Emeus crassus † Euryapteryx curtus Analyses of fossil moa bone assemblages have provided detailed data on
558-400: A number of cryptic evolutionary lineages occurred in several moa genera. These may eventually be classified as species or subspecies; Megalapteryx benhami (Archey) is synonymised with M. didinus (Owen) because the bones of both share all essential characters. Size differences can be explained by a north–south cline combined with temporal variation such that specimens were larger during
620-554: A number of plant species evolved to avoid moa browsing. Divaricating plants such as Pennantia corymbosa (the kaikōmako), which have small leaves and a dense mesh of branches, and Pseudopanax crassifolius (the horoeka or lancewood), which has tough juvenile leaves, are possible examples of plants that evolved in such a way. Likewise, it has been suggested that heteroblasty might be a response to moa browsing. Like many other birds, moa swallowed gizzard stones ( gastroliths ), which were retained in their muscular gizzards , providing
682-518: A poor predictor of body mass. Examples of other selective factors that may contribute to body mass changes are the size of food items available, effects of body size on success as a predator , effects of body size on vulnerability to predation, and resource availability. For example, if an organism is adapted to tolerate cold temperatures, it may also tolerate periods of food shortage, due to correlation between cold temperature and food scarcity. A larger organism can rely on its greater fat stores to provide
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#1732772273446744-464: A range of plant species and plant parts, including fibrous twigs and leaves taken from low trees and shrubs. The beak of Pachyornis elephantopus was analogous to a pair of secateurs , and could clip the fibrous leaves of New Zealand flax ( Phormium tenax ) and twigs up to at least 8 mm in diameter. Moa filled the ecological niche occupied in other countries by large browsing mammals such as antelope and llamas . Some biologists contend that
806-657: A reconsideration of the height of larger moa. However, Māori rock art depicts moa or moa-like birds (likely geese or adzebills ) with necks upright, indicating that moa were more than capable of assuming both neck postures. No records survive of what sounds moa made, though some idea of their calls can be gained from fossil evidence. The trachea of moa were supported by many small rings of bone known as tracheal rings. Excavation of these rings from articulated skeletons has shown that at least two moa genera ( Euryapteryx and Emeus ) exhibited tracheal elongation, that is, their trachea were up to 1 m (3 ft) long and formed
868-470: A reduced ability to avoid stressful environments, such as by burrowing. In addition to being a general pattern across space, Bergmann's rule has been reported in populations over historical and evolutionary time when exposed to varying thermal regimes. In particular, temporary, reversible dwarfing of mammals has been noted during two relatively brief upward excursions in temperature during the Paleogene :
930-538: A similar pattern to the South Island. The other moa species present in the North Island ( Euryapteryx gravis , E. curtus , and Pachyornis geranoides ) tended to inhabit drier forest and shrubland habitats. P. geranoides occurred throughout the North Island. The distributions of E. gravis and E. curtus were almost mutually exclusive, the former having only been found in coastal sites around
992-514: Is a Polynesian term for domestic fowl. The name was not in common use among the Māori by the time of European contact, likely because the bird it described had been extinct for some time, and traditional stories about it were rare. The earliest record of the name was by missionaries William Williams and William Colenso in January 1838; Colenso speculated that the birds may have resembled gigantic fowl. In 1912, Māori chief Urupeni Pūhara claimed that
1054-641: Is a phylogeny of Palaeognathae generated by Mitchell (2014) with some clade names after Yuri et al. (2013). It provides the position of the moa (Dinornithiformes) within the larger context of the "ancient jawed" (Palaeognathae) birds: Struthioniformes ( ostriches ) [REDACTED] Rheiformes ( rhea ) [REDACTED] Tinamiformes ( tinamous ) [REDACTED] † Dinornithiformes (moa) [REDACTED] Apterygiformes ( kiwi ) [REDACTED] † Aepyornithiformes ( elephant bird ) [REDACTED] Casuariidae ( cassowary ) [REDACTED] Dromaiidae ( emu ) [REDACTED] The cladogram below gives
1116-481: Is also reduced, or in comparison of tropical and temperate brachiopods, perhaps because tropical brachiopods have evolved to smaller sizes to successfully evade predation). In 1937 German zoologist and ecologist Richard Hesse proposed an extension of Bergmann's rule. Hesse's rule, also known as the heart–weight rule, states that species inhabiting colder climates have a larger heart in relation to body weight than closely related species inhabiting warmer climates. In
1178-464: Is characterised by small, slit-shaped pores. The eggs of most moa species were white, although those of the upland moa ( Megalapteryx didinus ) were blue-green. A 2010 study by Huynen et al. found that the eggs of certain species were fragile, only around a millimetre in shell thickness: "Unexpectedly, several thin-shelled eggs were also shown to belong to the heaviest moa of the genera Dinornis , Euryapteryx , and Emeus , making these, to our knowledge,
1240-403: Is characteristic of crustaceans). The size trend has been observed in hyperiid and gammarid amphipods , copepods , stomatopods , mysids , and planktonic euphausiids , both in comparisons of related species as well as within widely distributed species. Deep-sea gigantism is observed in some of the same groups, possibly for the same reasons. An additional factor in aquatic species may be
1302-459: Is no exact agreement, with different taxonomists each taking a different position. There are no hard rules that a taxonomist needs to follow in describing or recognizing an order. Some taxa are accepted almost universally, while others are recognized only rarely. The name of an order is usually written with a capital letter. For some groups of organisms, their orders may follow consistent naming schemes . Orders of plants , fungi , and algae use
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#17327722734461364-669: Is the intraspecific variation of bone sizes, between glacial and interglacial periods (see Bergmann’s rule and Allen’s rule ), as well as sexual dimorphism being evident in several species. Dinornis seems to have had the most pronounced sexual dimorphism, with females being up to 150% as tall and 280% as heavy as males—so much bigger that they were classified as separate species until 2003. A 2009 study showed that Euryapteryx curtus and E. gravis were synonyms. A 2010 study explained size differences among them as sexual dimorphism. A 2012 morphological study interpreted them as subspecies, instead. Analyses of ancient DNA have determined that
1426-659: The Prodromus Systematis Naturalis Regni Vegetabilis of Augustin Pyramus de Candolle and the Genera Plantarum of Bentham & Hooker, it indicated taxa that are now given the rank of family (see ordo naturalis , ' natural order '). In French botanical publications, from Michel Adanson 's Familles naturelles des plantes (1763) and until the end of the 19th century, the word famille (plural: familles )
1488-490: The Oligocene drowning. This does not imply that moa were previously absent from the North Island, but that only those from the South Island survived, because only the South Island was above sea level. Bunce et al. (2009) argued that moa ancestors survived on the South Island and then recolonised the North Island about 2 Myr later, when the two islands rejoined after 30 Myr of separation. The presence of Miocene moa in
1550-662: The Paleocene-Eocene thermal maximum and the Eocene Thermal Maximum 2 . Human populations near the poles, including the Inuit , Aleut , and Sami people , are on average heavier than populations from mid-latitudes, consistent with Bergmann's rule. They also tend to have shorter limbs and broader trunks, consistent with Allen's rule . According to Marshall T. Newman in 1953, Native American populations are generally consistent with Bergmann's rule although
1612-564: The kiwi , the Australian emu , and cassowary were thought to be most closely related to moa. Although dozens of species were described in the late 19th and early 20th centuries, many were based on partial skeletons and turned out to be synonyms . Currently, 11 species are formally recognised, although recent studies using ancient DNA recovered from bones in museum collections suggest that distinct lineages exist within some of these. One factor that has caused much confusion in moa taxonomy
1674-565: The nests themselves. Excavations of rock shelters in the eastern North Island during the 1940s found moa nests, which were described as "small depressions obviously scratched out in the soft dry pumice ". Moa nesting material has also been recovered from rock shelters in the Central Otago region of the South Island, where the dry climate has preserved plant material used to build the nesting platform (including twigs clipped by moa bills). Seeds and pollen within moa coprolites found among
1736-411: The 18.5 Mya split suggested by Baker et al. (2005). This does not necessarily mean there was no speciation between the arrival 60 Mya and the basal split 5.8 Mya, but the fossil record is lacking and most likely the early moa lineages existed, but became extinct before the basal split 5.8 Mya. The presence of Miocene -aged species certainly suggests that moa diversification began before
1798-746: The Otiran glacial period (the last ice age in New Zealand). Similar temporal size variation is known for the North Island's Pachyornis mappini . Some of the other size variation for moa species can probably be explained by similar geographic and temporal factors. The earliest moa remains come from the Miocene Saint Bathans Fauna . Known from multiple eggshells and hind limb elements, these represent at least two already fairly large-sized species. The currently recognised genera and species are: Two unnamed species are also known from
1860-534: The Saint Bathans Fauna. Because moa are a group of flightless birds with no vestiges of wing bones, questions have been raised about how they arrived in New Zealand, and from where. Many theories exist about the moa's arrival and radiation in New Zealand, but the most recent theory suggests that they arrived in New Zealand about 60 million years ago (Mya) and split from the "basal" (see below) moa species, Megalapteryx , about 5.8 Mya instead of
1922-631: The Saint Bathans fauna seems to suggest that these birds increased in size soon after the Oligocene drowning event, if they were affected by it at all. Bunce et al. also concluded that the highly complex structure of the moa lineage was caused by the formation of the Southern Alps about 6 Mya, and the habitat fragmentation on both islands resulting from Pleistocene glacial cycles, volcanism , and landscape changes. The cladogram below
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1984-610: The South Island, but the basic pattern of moa-habitat relationships was the same. The South Island and the North Island shared some moa species ( Euryapteryx gravis , Anomalopteryx didiformis ), but most were exclusive to one island, reflecting divergence over several thousand years since lower sea level in the Ice Age had made a land bridge across the Cook Strait . In the North Island, Dinornis novaezealandiae and Anomalopteryx didiformis dominated in high-rainfall forest habitat,
2046-536: The cold climate and small body size combination of the Eastern Inuit, Canoe Nation, Yuki people , Andes natives and Harrison Lake Lillooet runs contrary to the expectations of Bergmann's rule. Newman contends that Bergmann's rule holds for the populations of Eurasia , but it does not hold for those of sub-Saharan Africa . Human populations also show a decrease in stature with an increase in mean annual temperature. Bergmann's rule holds for Africans with
2108-472: The ending -anae that was initiated by Armen Takhtajan 's publications from 1966 onwards. The order as a distinct rank of biological classification having its own distinctive name (and not just called a higher genus ( genus summum )) was first introduced by the German botanist Augustus Quirinus Rivinus in his classification of plants that appeared in a series of treatises in the 1690s. Carl Linnaeus
2170-425: The energy needed for survival as well being able to procreate for longer periods. Resource availability is a major constraint on the overall success of many organisms. Resource scarcity can limit the total number of organisms in a habitat, and over time can also cause organisms to adapt by becoming smaller in body size. Resource availability thus becomes a modifying restraint on Bergmann's Rule. Some examinations of
2232-910: The field of zoology , the Linnaean orders were used more consistently. That is, the orders in the zoology part of the Systema Naturae refer to natural groups. Some of his ordinal names are still in use, e.g. Lepidoptera (moths and butterflies) and Diptera (flies, mosquitoes, midges, and gnats). In virology , the International Committee on Taxonomy of Viruses 's virus classification includes fifteen taxomomic ranks to be applied for viruses , viroids and satellite nucleic acids : realm , subrealm , kingdom , subkingdom, phylum , subphylum , class, subclass, order, suborder, family, subfamily , genus, subgenus , and species. There are currently fourteen viral orders, each ending in
2294-449: The genus Rapicactus are larger in cooler environments, as their stem diameter increases with altitude and particularly with latitude. However, since Rapicactus grow in a distributional area in which average precipitation tends to diminish at higher latitudes, and their body size is not conditioned by climatic variables, this could suggest a possible Bergmann trend. The earliest explanation, given by Bergmann when originally formulating
2356-422: The greater dissolved oxygen concentration at lower temperature. This view is supported by the reduced size of crustaceans in high-altitude lakes. A further possible influence on invertebrates is reduced predation pressure at high latitude. A study of shallow water brachiopods found that predation was reduced in polar areas relative to temperate latitudes (the same trend was not found in deep water, where predation
2418-481: The habitat preferences of individual moa species, and revealed distinctive regional moa faunas: The two main faunas identified in the South Island include: A ' subalpine fauna' might include the widespread D. robustus , and the two other moa species that existed in the South Island: Significantly less is known about North Island paleofaunas, due to the scarcity of fossil sites compared to
2480-562: The height of a shape, its surface area-to-volume ratio will decrease. Modeling a person's trunk and limbs as cylinders shows a 17% decrease in surface area-to-volume ratio from a person who is five feet tall to a person who is six feet tall even at the same body mass index (BMI) . In marine crustaceans , it has been proposed that an increase in size with latitude is observed because decreasing temperature results in increased cell size and increased life span , both of which lead to an increase in maximum body size (continued growth throughout life
2542-535: The moa's traditional name was "te kura" (the red bird). Moa skeletons were traditionally reconstructed in an upright position to create impressive height, but analysis of their vertebral articulations indicates that they probably carried their heads forward, in the manner of a kiwi . The spine was attached to the rear of the head rather than the base, indicating the horizontal alignment. This would have let them graze on low vegetation, while being able to lift their heads and browse trees when necessary. This has resulted in
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2604-823: The morphology of migratory birds used bodies of birds which had collided with buildings in Chicago from 1978 to 2016. The length of birds' lower leg bones (an indicator of body size) shortened by an average of 2.4% and their wings lengthened by 1.3%. A similar study published in 2021 used measurements of 77 nonmigratory bird species captured live for banding in lowland Amazon rainforest . Between 1979 and 2019, all study species have gotten smaller on average, by up to 2% per decade. The morphological changes are regarded as resulting from global warming , and may demonstrate an example of evolutionary change following Bergmann's rule. Bergmann's rule has been reported to be vaguely followed by female crocodilians. However, for turtles or lizards
2666-436: The most fragile of all avian eggs measured to date. Moreover, sex-specific DNA recovered from the outer surfaces of eggshells belonging to species of Dinornis and Euryapteryx suggest that these very thin eggs were likely to have been incubated by the lighter males. The thin nature of the eggshells of these larger species of moa, even if incubated by the male, suggests that egg breakage in these species would have been common if
2728-420: The nesting material provide evidence that the nesting season was late spring to summer. Fragments of moa eggshell are often found in archaeological sites and sand dunes around the New Zealand coast. Thirty-six whole moa eggs exist in museum collections and vary greatly in size (from 120–240 millimetres (4.7–9.4 in) in length and 91–178 millimetres (3.6–7.0 in) wide). The outer surface of moa eggshell
2790-452: The order is a taxonomic rank used in the classification of organisms and recognized by the nomenclature codes . An immediately higher rank, superorder , is sometimes added directly above order, with suborder directly beneath order. An order can also be defined as a group of related families. What does and does not belong to each order is determined by a taxonomist , as is whether a particular order should be recognized at all. Often there
2852-462: The overall size of the animals, but does not include body proportions like Allen's rule does. Although originally formulated in relation to species within a genus, it has often been recast in relation to populations within a species. It is also often cast in relation to latitude. It is possible that the rule also applies to some plants, such as Rapicactus . The rule is named after nineteenth century German biologist Carl Bergmann , who described
2914-541: The pattern in 1847, although he was not the first to notice it. Bergmann's rule is most often applied to mammals and birds which are endotherms , but some researchers have also found evidence for the rule in studies of ectothermic species, such as the ant Leptothorax acervorum . While Bergmann's rule appears to hold true for many mammals and birds, there are exceptions. Larger-bodied animals tend to conform more closely to Bergmann's rule than smaller-bodied animals, at least up to certain latitudes. This perhaps reflects
2976-430: The pygmy phenotype and other pygmy peoples . These populations show a shorter stature and smaller body size due to an adaptation to hotter and more humid environments. With elevated environmental humidity, evaporative cooling (sweating) is a less effective way to dissipate body heat, but a higher surface area to volume ratio should provide a slight advantage through passive convective heat loss. A 2019 study of changes in
3038-406: The rule's validity has not been supported. Evidence of Bergmann's rule has been found in marine copepods . Bergmann's rule cannot generally be applied to plants. Regarding Cactaceae , the case of the saguaro ( Carnegiea gigantea ), once described as "a botanical Bergmann trend", has instead been shown to depend on rainfall, particularly winter precipitation, and not temperature. Members of
3100-452: The rule, is that larger animals have a lower surface area to volume ratio than smaller animals, so they radiate less body heat per unit of mass, and therefore stay warmer in cold climates . Warmer climates impose the opposite problem: body heat generated by metabolism needs to be dissipated quickly rather than stored within. Thus, the higher surface area-to-volume ratio of smaller animals in hot and dry climates facilitates heat loss through
3162-420: The same position. Michael Benton (2005) inserted them between superorder and magnorder instead. This position was adopted by Systema Naturae 2000 and others. In botany , the ranks of subclass and suborder are secondary ranks pre-defined as respectively above and below the rank of order. Any number of further ranks can be used as long as they are clearly defined. The superorder rank is commonly used, with
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#17327722734463224-418: The skin and helps cool the body. When analyzing Bergmann's Rule in the field, groups of populations being studied are of different thermal environments, and also have been separated long enough to genetically differentiate in response to these thermal conditions. The relationship between stature and mean annual temperature can be explained by modeling any shape that is increasing in any dimension. As you increase
3286-405: The smallest, the bush moa ( Anomalopteryx didiformis ), was around the size of a turkey . Estimates of the moa population when Polynesians settled New Zealand circa 1300 vary between 58,000 and approximately 2.5 million. Moa are traditionally placed in the ratite group. However, genetic studies have found that their closest relatives are the flighted South American tinamous , once considered
3348-769: The southern half of the North Island. About eight moa trackways , with fossilised moa footprint impressions in fluvial silts, have been found in the North Island, including Waikanae Creek (1872), Napier (1887), Manawatū River (1895), Marton (1896), Palmerston North (1911) (see photograph to left), Rangitīkei River (1939), and under water in Lake Taupō (1973). Analysis of the spacing of these tracks indicates walking speeds between 3 and 5 km/h (1.75–3 mph). Their diet has been deduced from fossilised contents of their gizzards and coprolites , as well as indirectly through morphological analysis of skull and beak, and stable isotope analysis of their bones. Moa fed on
3410-545: The split between Megalapteryx and the other taxa. The Oligocene Drowning Maximum event, which occurred about 22 Mya, when only 18% of present-day New Zealand was above sea level, is very important in the moa radiation. Because the basal moa split occurred so recently (5.8 Mya), it was argued that ancestors of the Quaternary moa lineages could not have been present on both the South and North Island remnants during
3472-777: The suffix -ales (e.g. Dictyotales ). Orders of birds and fishes use the Latin suffix -iformes meaning 'having the form of' (e.g. Passeriformes ), but orders of mammals and invertebrates are not so consistent (e.g. Artiodactyla , Actiniaria , Primates ). For some clades covered by the International Code of Zoological Nomenclature , several additional classifications are sometimes used, although not all of these are officially recognized. In their 1997 classification of mammals , McKenna and Bell used two extra levels between superorder and order: grandorder and mirorder . Michael Novacek (1986) inserted them at
3534-500: The suffix -virales . Bergmann%E2%80%99s rule Bergmann's rule is an ecogeographical rule that states that, within a broadly distributed taxonomic clade , populations and species of larger size are found in colder environments, while populations and species of smaller size are found in warmer regions. The rule derives from the relationship between size in linear dimensions meaning that both height and volume will increase in colder environments. Bergmann's rule only describes
3596-514: The three species of Dinornis were reclassified as two species, one each formerly occurring on New Zealand's North Island ( D. novaezealandiae ) and South Island ( D. robustus ); D. robustus however, comprises three distinct genetic lineages and may eventually be classified as many species, as discussed above. Examination of growth rings in moa cortical bone has revealed that these birds were K-selected , as are many other large endemic New Zealand birds. They are characterised by having
3658-475: The typical contact method of avian egg incubation was used." Despite the bird's extinction, the high yield of DNA available from recovered fossilised eggs has allowed the moa's genome to be sequenced. Order (biology) Order ( Latin : ordo ) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy . It is classified between family and class . In biological classification ,
3720-578: The word family ( familia ) was assigned to the rank indicated by the French famille , while order ( ordo ) was reserved for a higher rank, for what in the 19th century had often been named a cohors (plural cohortes ). Some of the plant families still retain the names of Linnaean "natural orders" or even the names of pre-Linnaean natural groups recognized by Linnaeus as orders in his natural classification (e.g. Palmae or Labiatae ). Such names are known as descriptive family names. In
3782-551: Was the first to apply it consistently to the division of all three kingdoms of nature (then minerals , plants , and animals ) in his Systema Naturae (1735, 1st. Ed.). For plants, Linnaeus' orders in the Systema Naturae and the Species Plantarum were strictly artificial, introduced to subdivide the artificial classes into more comprehensible smaller groups. When the word ordo was first consistently used for natural units of plants, in 19th-century works such as
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#17327722734463844-561: Was used as a French equivalent for this Latin ordo . This equivalence was explicitly stated in the Alphonse Pyramus de Candolle 's Lois de la nomenclature botanique (1868), the precursor of the currently used International Code of Nomenclature for algae, fungi, and plants . In the first international Rules of botanical nomenclature from the International Botanical Congress of 1905,
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