Misplaced Pages

#58941

25-400: Acerentomata Eosentomata Sinentomata The Protura , or proturans , and sometimes nicknamed coneheads , are very small (0.6–1.5mm long), soil-dwelling animals, so inconspicuous they were not noticed until the 20th century. The Protura constitute an order of hexapods that were previously regarded as insects, and sometimes treated as a class in their own right. Some evidence indicates

50-478: 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 the suffix -ales (e.g. Dictyotales ). Orders of birds and fishes use

75-462: A second egg stage to reach their adult form. This hypothesis attempts to explain the developmental differences between hemimetabolous and holometabolous metamorphosis. Though there is little evidence supporting Harvey's hypothesis, it is still significant to modern research in nymphs. In fly fishing with artificial flies, this stage of aquatic insects is the basis for an entire series of representative patterns for trout. They account for over half of

100-538: Is achieved. Further moults may occur, but do not add additional body segments; it is still not known whether the adults continue to moult throughout their lives. Eggs have been observed in only a few species. In most proturan families, five developmental stages follow the egg stage: the prenymph hatches from the egg and has only weakly developed mouthparts and 8 abdominal segments; nymph I follows and has fully developed mouthparts; nymph II has 9 abdominal segments; "maturus junior" has 11 abdominal segments, and moults into

125-628: 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 )

150-632: The bark of trees, as well as in animal burrows. They are generally restricted to the uppermost 0.1 m (3.9 in), but have been found as deep as 0.25 m (9.8 in). Although they are sometimes regarded as uncommon, proturans are most likely overlooked because of their small size, as densities of over 90,000 individuals per square metre have been recorded. The diet of proturans has not yet been sufficiently observed to be characterised. In laboratory culture, they may be fed mycorrhizal fungi , dead mites and pulverized, dried mushrooms; they are believed to feed on decaying vegetable matter and fungi in

175-681: The heterometabolous insects, as their adult and immature stages live in different environments ( terrestrial vs. aquatic ). In 1628, English physician William Harvey published An Anatomical Disquisition on the Motion of the Heart and Blood in Animals. In his writing, Harvey hypothesized that the pupal stage in insects was the result of imperfect eggs. While some eggs produced smaller versions of fully-matured insects known as nymphs, others created intermediate forms. Thus, these intermediate forms must go through

200-684: 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

225-492: The Odonata, Ephemeroptera, and Plecoptera orders, are also called naiads , an Ancient Greek name for mythological water nymphs . Some entomologists have said that the terms larva, nymph and naiad should be used according to the developmental mode classification (hemimetabolous, paurometabolous or holometabolous) but others have pointed out that there is no real confusion. In older literature, these were sometimes referred to as

250-586: The Protura are basal to all other hexapods, although not all researchers consider them Hexapoda , rendering the monophyly of Hexapoda unsettled. Uniquely among hexapods, proturans show anamorphic development, whereby body segments are added during moults . There are close to 800 species, described in seven families . Nearly 300 species are contained in a single genus , Eosentomon . Proturans have no eyes, wings, or antennae, and, lacking pigmentation , are usually whitish or pale brown. The sensory function of

275-431: The absent antennae is fulfilled by the first pair of the three pairs of five-segmented legs , which are held up, pointing forward, and bearing numerous tarsal sensilla and sensory hairs. They ambulate using the four rear legs. The head is conical, and bears two pseudoculi with unknown function. The body is elongated and cylindrical, with a post-anal telson at the end. The mouthparts are entognathous (enclosed within

SECTION 10

#1732854510059

300-399: The animals. The first species to be described was Acerentomon doderoi , published in 1907 by Silvestri, based on material found near Syracuse, New York . Order (biology) 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 is no exact agreement, with different taxonomists each taking

325-607: The emergence of genitalia. In addition, while a nymph moults , it never enters a pupal stage. Instead, the final moult results in an adult insect. Nymphs undergo multiple stages of development called instars . Many species of arthropods have nymph stages. This includes the orders Orthoptera ( crickets , grasshoppers and locusts ), Hemiptera ( cicadas , shield bugs , whiteflies , aphids , leafhoppers , froghoppers , treehoppers ), mayflies , termites , cockroaches , mantises , stoneflies and Odonata ( dragonflies and damselflies ). Nymphs of aquatic insects , as in

350-468: 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

375-888: 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

400-601: The genital opening lies between the eleventh segment and the telson of the adult. During mating, the genitalia of both sexes are everted from an abdominal chamber. Only the two families Eosentomidae and Sinentomidae possess a simple tracheal system with a pair of spiracles on both the mesothorax and the metathorax , while proturans in the remaining families lack these structures and perform gas exchange by diffusion . Proturans live chiefly in soil , mosses , and leaf litter of moist temperate forests that are not too acidic. They have also been found beneath rocks or under

425-533: The head capsule) and consist of narrow mandibles and maxillae. There are no cerci at the end of the abdomen, which gives the group their name, from the Greek proto- (meaning "first", in this case implying primitive), and ura , meaning "tail". The first three abdominal segments bear short limb-like appendages , called "styli". The first pair of styli is two-segmented, while the second and third pair are either two-segmented or unsegmented. The genitalia are internal and

450-420: 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

475-401: The sexually mature adult. Male individuals of the family Acerentomidae differ from this five-stage scheme, having an additional developmental stage, the preimago , which has partially developed genitalia and appears between the "maturus junior" and the adult stage. Proturans were first discovered in the early 20th century, when Filippo Silvestri and Antonio Berlese independently described

500-436: The suffix -virales . Nymph (biology) In biology , a nymph (from Ancient Greek νύμφα nūmphē meaning "bride") is the juvenile form of some invertebrates , particularly insects , which undergoes gradual metamorphosis ( hemimetabolism ) before reaching its adult stage. Unlike a typical larva , a nymph's overall form already resembles that of the adult, except for a lack of wings (in winged species) and

525-477: The wild. The styliform mouthparts suggest the Protura may be fluid feeders, based on evidence that some species suck out the liquid contents of fungal hyphae . Proturan species which spend their lives near the soil surface generally produce one new generation of offspring each year; they also possess longer legs. Species living at deeper soil levels have shorter legs and tend to reproduce less seasonally. Some migratory proturan species move to deeper soil layers for

SECTION 20

#1732854510059

550-403: The winter and ascend to shallower soil layers for the summer. Proturans play a role in soil formation and composition by speeding decomposition, helping in the breakdown of leaf litter and recycling nutrients into the soil. The nymph has 8 abdominal segments plus the telson; the number of abdominal segments increases through moulting until the full adult complement of 11 abdominal segments

575-574: 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

600-543: 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

625-540: 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,

#58941