48-415: Leptocleidia is a clade of plesiosauroids . The group was erected in 2007 as Leptocleidoidea. Although established as a clade, the name Leptocleidoidea implies that it is a superfamily . Leptocleidoidea is placed within the superfamily Plesiosauroidea , so it was renamed Leptocleidia by Hilary F. Ketchum and Roger B. J. Benson (2010) to avoid confusion with ranks. Leptocleidia is a node-based taxon which
96-412: A Proto-Indo-European word *morwi- was the root for Sanskrit vamrah , Greek μύρμηξ mýrmēx , Old Church Slavonic mraviji , Old Irish moirb , Old Norse maurr , Dutch mier , Swedish myra , Danish myre , Middle Dutch miere , and Crimean Gothic miera . The family Formicidae belongs to the order Hymenoptera , which also includes sawflies , bees , and wasps . Ants evolved from
144-488: A cosmopolitan distribution . They are found on all continents except Antarctica , and only a few large islands, such as Greenland , Iceland , parts of Polynesia and the Hawaiian Islands lack native ant species. Ants occupy a wide range of ecological niches and exploit many different food resources as direct or indirect herbivores, predators and scavengers. Most ant species are omnivorous generalists , but
192-590: A monophyletic group or natural group , is a grouping of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree . In the taxonomical literature, sometimes the Latin form cladus (plural cladi ) is used rather than the English form. Clades are the fundamental unit of cladistics , a modern approach to taxonomy adopted by most biological fields. The common ancestor may be an individual,
240-588: A population , or a species ( extinct or extant ). Clades are nested, one in another, as each branch in turn splits into smaller branches. These splits reflect evolutionary history as populations diverged and evolved independently. Clades are termed monophyletic (Greek: "one clan") groups. Over the last few decades, the cladistic approach has revolutionized biological classification and revealed surprising evolutionary relationships among organisms. Increasingly, taxonomists try to avoid naming taxa that are not clades; that is, taxa that are not monophyletic . Some of
288-479: A "ladder", with supposedly more "advanced" organisms at the top. Taxonomists have increasingly worked to make the taxonomic system reflect evolution. When it comes to naming , this principle is not always compatible with the traditional rank-based nomenclature (in which only taxa associated with a rank can be named) because not enough ranks exist to name a long series of nested clades. For these and other reasons, phylogenetic nomenclature has been developed; it
336-446: A branch of mammals that split off after the end of the period when the clade Dinosauria stopped being the dominant terrestrial vertebrates 66 million years ago. The original population and all its descendants are a clade. The rodent clade corresponds to the order Rodentia, and insects to the class Insecta. These clades include smaller clades, such as chipmunk or ant , each of which consists of even smaller clades. The clade "rodent"
384-623: A clade can be described based on two different reference points, crown age and stem age. The crown age of a clade refers to the age of the most recent common ancestor of all of the species in the clade. The stem age of a clade refers to the time that the ancestral lineage of the clade diverged from its sister clade. A clade's stem age is either the same as or older than its crown age. Ages of clades cannot be directly observed. They are inferred, either from stratigraphy of fossils , or from molecular clock estimates. Viruses , and particularly RNA viruses form clades. These are useful in tracking
432-400: A conservative estimate of the ants at about 20 × 10 (20 quadrillion). Ants range in size from 0.75 to 52 millimetres (0.030–2.0 in), the largest species being the fossil Titanomyrma giganteum , the queen of which was 6 cm ( 2 + 1 ⁄ 2 in) long with a wingspan of 15 cm (6 in). Ants vary in colour; most ants are yellow to red or brown to black, but
480-499: A few are specialist feeders. There is considerable variation in ant abundance across habitats, peaking in the moist tropics to nearly six times that found in less suitable habitats. Their ecological dominance has been examined primarily using estimates of their biomass : myrmecologist E. O. Wilson had estimated in 2009 that at any one time the total number of ants was between one and ten quadrillion ( short scale ) (i.e., between 10 and 10 ) and using this estimate he had suggested that
528-406: A few species are green and some tropical species have a metallic lustre . More than 13,800 species are currently known (with upper estimates of the potential existence of about 22,000; see the article List of ant genera ), with the greatest diversity in the tropics. Taxonomic studies continue to resolve the classification and systematics of ants. Online databases of ant species, including AntWeb and
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#1732798690024576-409: A high resolution image. They also have three small ocelli (simple eyes) on the top of the head that detect light levels and polarization . Compared to vertebrates , ants tend to have blurrier eyesight, particularly in smaller species, and a few subterranean taxa are completely blind . However, some ants, such as Australia's bulldog ant , have excellent vision and are capable of discriminating
624-519: A lineage within the stinging wasps , and a 2013 study suggests that they are a sister group of the Apoidea . However, since Apoidea is a superfamily, ants must be upgraded to the same rank. A more detailed basic taxonomy was proposed in 2020. Three species of the extinct mid- Cretaceous genera Camelomecia and Camelosphecia were placed outside of the Formicidae, in a separate clade within
672-446: A node-like petiole . The head, mesosoma , and metasoma are the three distinct body segments (formally tagmata ). The petiole forms a narrow waist between their mesosoma ( thorax plus the first abdominal segment, which is fused to it) and gaster (abdomen less the abdominal segments in the petiole). The petiole may be formed by one or two nodes (the second alone, or the second and third abdominal segments). Tergosternal fusion, when
720-403: A protective casing around the body and a point of attachment for muscles, in contrast to the internal skeletons of humans and other vertebrates . Insects do not have lungs ; oxygen and other gases, such as carbon dioxide , pass through their exoskeleton via tiny valves called spiracles . Insects also lack closed blood vessels ; instead, they have a long, thin, perforated tube along the top of
768-422: A revised taxonomy based on a concept strongly resembling clades, although the term clade itself would not be coined until 1957 by his grandson, Julian Huxley . German biologist Emil Hans Willi Hennig (1913–1976) is considered to be the founder of cladistics . He proposed a classification system that represented repeated branchings of the family tree, as opposed to the previous systems, which put organisms on
816-430: A single gene of Solenopsis invicta can decide whether the colony will have single or multiple queens. The Australian jack jumper ant ( Myrmecia pilosula ) has only a single pair of chromosomes (with the males having just one chromosome as they are haploid ), the lowest number known for any animal, making it an interesting subject for studies in the genetics and developmental biology of social insects. Genome size
864-429: A suffix added should be e.g. "dracohortian". A clade is by definition monophyletic , meaning that it contains one ancestor which can be an organism, a population, or a species and all its descendants. The ancestor can be known or unknown; any and all members of a clade can be extant or extinct. The science that tries to reconstruct phylogenetic trees and thus discover clades is called phylogenetics or cladistics ,
912-498: Is paraphyletic In 1966, E. O. Wilson and his colleagues identified the fossil remains of an ant ( Sphecomyrma ) that lived in the Cretaceous period. The specimen, trapped in amber dating back to around 92 million years ago, has features found in some wasps, but not found in modern ants. The oldest fossils of ants date to the mid-Cretaceous, around 100 million years ago, which belong to extinct stem-groups such as
960-476: Is in turn included in the mammal, vertebrate and animal clades. The idea of a clade did not exist in pre- Darwinian Linnaean taxonomy , which was based by necessity only on internal or external morphological similarities between organisms. Many of the better known animal groups in Linnaeus's original Systema Naturae (mostly vertebrate groups) do represent clades. The phenomenon of convergent evolution
1008-515: Is responsible for many cases of misleading similarities in the morphology of groups that evolved from different lineages. With the increasing realization in the first half of the 19th century that species had changed and split through the ages, classification increasingly came to be seen as branches on the evolutionary tree of life . The publication of Darwin's theory of evolution in 1859 gave this view increasing weight. In 1876 Thomas Henry Huxley , an early advocate of evolutionary theory, proposed
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#17327986900241056-489: Is still controversial. As an example, see the full current classification of Anas platyrhynchos (the mallard duck) with 40 clades from Eukaryota down by following this Wikispecies link and clicking on "Expand". The name of a clade is conventionally a plural, where the singular refers to each member individually. A unique exception is the reptile clade Dracohors , which was made by haplology from Latin "draco" and "cohors", i.e. "the dragon cohort "; its form with
1104-544: The Cretaceous period. More than 13,800 of an estimated total of 22,000 species have been classified. They are easily identified by their geniculate (elbowed) antennae and the distinctive node-like structure that forms their slender waists. Ants form colonies that range in size from a few dozen individuals often living in small natural cavities to highly organised colonies that may occupy large territories with sizeable nest that consist of millions of individuals or into
1152-700: The Haidomyrmecinae , Sphecomyrminae and Zigrasimeciinae , with modern ant subfamilies appearing towards the end of the Cretaceous around 80–70 million years ago. Ants diversified extensively during the Angiosperm Terrestrial Revolution and assumed ecological dominance around 60 million years ago. Some groups, such as the Leptanillinae and Martialinae , are suggested to have diversified from early primitive ants that were likely to have been predators underneath
1200-810: The Paleogene period . By the Oligocene and Miocene , ants had come to represent 20–40% of all insects found in major fossil deposits. Of the species that lived in the Eocene epoch, around one in 10 genera survive to the present. Genera surviving today comprise 56% of the genera in Baltic amber fossils (early Oligocene), and 92% of the genera in Dominican amber fossils (apparently early Miocene). Termites live in colonies and are sometimes called "white ants", but termites are only distantly related to ants. They are
1248-438: The haplodiploid sex-determination system in ants, workers of a number of species can lay unfertilised eggs that become fully fertile, haploid males. The role of workers may change with their age and in some species, such as honeypot ants , young workers are fed until their gasters are distended, and act as living food storage vessels. These food storage workers are called repletes . For instance, these replete workers develop in
1296-485: The mandibles , used to carry food, manipulate objects, construct nests, and for defence. In some species, a small pocket (infrabuccal chamber) inside the mouth stores food, so it may be passed to other ants or their larvae. Both the legs and wings of the ant are attached to the mesosoma ("thorax"). The legs terminate in a hooked claw which allows them to hook on and climb surfaces. Only reproductive ants ( queens and males) have wings. Queens shed their wings after
1344-457: The nuptial flight , leaving visible stubs, a distinguishing feature of queens. In a few species, wingless queens ( ergatoids ) and males occur. The metasoma (the "abdomen") of the ant houses important internal organs, including those of the reproductive, respiratory (tracheae), and excretory systems. Workers of many species have their egg-laying structures modified into stings that are used for subduing prey and defending their nests. In
1392-605: The red imported fire ant ( Solenopsis invicta ) of South America, are regarded as invasive species in other parts of the world, establishing themselves in areas where they have been introduced accidentally. The word ant and the archaic word emmet are derived from ante , emete of Middle English , which come from ǣmette of Old English ; these are all related to Low Saxon e(e)mt , empe and varieties ( Old Saxon emeta ) and to German Ameise ( Old High German āmeiza ). All of these words come from West Germanic * ǣmaitjōn , and
1440-509: The Hymenoptera Name Server, help to keep track of the known and newly described species. The relative ease with which ants may be sampled and studied in ecosystems has made them useful as indicator species in biodiversity studies. Ants are distinct in their morphology from other insects in having geniculate (elbowed) antennae , metapleural glands , and a strong constriction of their second abdominal segment into
1488-758: The North American honeypot ant Myrmecocystus mexicanus . Usually the largest workers in the colony develop into repletes; and, if repletes are removed from the colony, other workers become repletes, demonstrating the flexibility of this particular polymorphism . This polymorphism in morphology and behaviour of workers initially was thought to be determined by environmental factors such as nutrition and hormones that led to different developmental paths ; however, genetic differences between worker castes have been noted in Acromyrmex sp. These polymorphisms are caused by relatively small genetic changes; differences in
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1536-1167: The ants appear to operate as a unified entity, collectively working together to support the colony. Ants have colonised almost every landmass on Earth . The only places lacking indigenous ants are Antarctica and a few remote or inhospitable islands. Ants thrive in moist tropical ecosystems and may exceed the combined biomass of wild birds and mammals. Their success in so many environments has been attributed to their social organisation and their ability to modify habitats, tap resources, and defend themselves. Their long co-evolution with other species has led to mimetic , commensal , parasitic , and mutualistic relationships. Ant societies have division of labour , communication between individuals, and an ability to solve complex problems . These parallels with human societies have long been an inspiration and subject of study. Many human cultures make use of ants in cuisine, medication, and rites. Some species are valued in their role as biological pest control agents. Their ability to exploit resources may bring ants into conflict with humans, however, as they can damage crops and invade buildings. Some species, such as
1584-556: The body (called the "dorsal aorta") that functions like a heart, and pumps haemolymph toward the head, thus driving the circulation of the internal fluids. The nervous system consists of a ventral nerve cord that runs the length of the body, with several ganglia and branches along the way reaching into the extremities of the appendages. An ant's head contains many sensory organs . Like most insects, ants have compound eyes made from numerous tiny lenses attached together. Ant eyes are good for acute movement detection, but do not offer
1632-515: The colonies of a few ant species, there are physical castes—workers in distinct size-classes, called minor (micrergates), median, and major ergates (macrergates). Often, the larger ants have disproportionately larger heads, and correspondingly stronger mandibles . Although formally known as dinergates, such individuals are sometimes called "soldier" ants because their stronger mandibles make them more effective in fighting, although they still are workers and their "duties" typically do not vary greatly from
1680-532: The distance and size of objects moving nearly a meter away. Based on experiments conducted to test their ability to differentiate between selected wavelengths of light, some ant species such as Camponotus blandus, Solenopsis invicta, and Formica cunicularia are thought to possess a degree of colour vision. Two antennae ("feelers") are attached to the head; these organs detect chemicals, air currents , and vibrations ; they also are used to transmit and receive signals through touch. The head has two strong jaws,
1728-874: The general superfamily Formicoidea , which, together with Apoidea, forms the higher-ranking group Formicapoidina . Fernández et al. (2021) suggest that the common ancestors of ants and apoids within the Formicapoidina probably existed as early as in the end of the Jurassic period, before divergence in the Cretaceous. Chrysidoidea Vespidae Rhopalosomatidae Pompilidae Mutillidae Tiphiidae Chyphotidae Scolioidea Apoidea Formicidae Myrmicinae Ectatomminae Heteroponerinae Formicinae Dolichoderinae Aneuretinae Pseudomyrmecinae Myrmeciinae Dorylinae‡ Ponerinae Agroecomyrmecinae Paraponerinae Proceratiinae Amblyoponinae Apomyrminae Leptanillinae Martialinae *Cerapachyinae
1776-403: The hundreds of millions in super colonies . Typical colonies consist of various castes of sterile, wingless females, most of which are workers (ergates), as well as soldiers (dinergates) and other specialised groups. Nearly all ant colonies also have some fertile males called "drones" and one or more fertile females called " queens " ( gynes ). The colonies are described as superorganisms because
1824-518: The latter term coined by Ernst Mayr (1965), derived from "clade". The results of phylogenetic/cladistic analyses are tree-shaped diagrams called cladograms ; they, and all their branches, are phylogenetic hypotheses. Three methods of defining clades are featured in phylogenetic nomenclature : node-, stem-, and apomorphy-based (see Phylogenetic nomenclature§Phylogenetic definitions of clade names for detailed definitions). The relationship between clades can be described in several ways: The age of
1872-489: The minor or median workers. In a few species, the median workers are absent, creating a sharp divide between the minors and majors. Weaver ants , for example, have a distinct bimodal size distribution. Some other species show continuous variation in the size of workers. The smallest and largest workers in Carebara diversa show nearly a 500-fold difference in their dry weights. Workers cannot mate; however, because of
1920-503: The original meaning of the word was "the biter" (from Proto-Germanic * ai- , "off, away" + * mait- "cut"). The family name Formicidae is derived from the Latin formīca ("ant") from which the words in other Romance languages , such as the Portuguese formiga , Italian formica , Spanish hormiga , Romanian furnică , and French fourmi are derived. It has been hypothesised that
1968-482: The relationships between organisms that the molecular biology arm of cladistics has revealed include that fungi are closer relatives to animals than they are to plants, archaea are now considered different from bacteria , and multicellular organisms may have evolved from archaea. The term "clade" is also used with a similar meaning in other fields besides biology, such as historical linguistics ; see Cladistics § In disciplines other than biology . The term "clade"
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2016-571: The spread of viral infections . HIV , for example, has clades called subtypes, which vary in geographical prevalence. HIV subtype (clade) B, for example is predominant in Europe, the Americas and Japan, whereas subtype A is more common in east Africa. Ant Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees , belong to the order Hymenoptera . Ants evolved from vespoid wasp ancestors in
2064-509: The sub-order Isoptera , and together with cockroaches , they form the order Blattodea . Blattodeans are related to mantids , crickets , and other winged insects that do not undergo complete metamorphosis . Like ants, termites are eusocial , with sterile workers, but they differ greatly in the genetics of reproduction. The similarity of their social structure to that of ants is attributed to convergent evolution . Velvet ants look like large ants, but are wingless female wasps . Ants have
2112-532: The surface of the soil. During the Cretaceous period, a few species of primitive ants ranged widely on the Laurasian supercontinent (the Northern Hemisphere ). Their representation in the fossil record is poor, in comparison to the populations of other insects, representing only about 1% of fossil evidence of insects in the era. Ants became dominant after adaptive radiation at the beginning of
2160-464: The tergite and sternite of a segment fuse together, can occur partly or fully on the second, third and fourth abdominal segment and is used in identification. Fourth abdominal tergosternal fusion was formerly used as character that defined the poneromorph subfamilies, Ponerinae and relatives within their clade, but this is no longer considered a synapomorphic character. Like other arthropods, ants have an exoskeleton , an external covering that provides
2208-400: The total biomass of all the ants in the world was approximately equal to the total biomass of the entire human race. More careful estimates made in 2022 which take into account regional variations puts the global ant contribution at 12 megatons of dry carbon, which is about 20% of the total human contribution, but greater than that of the wild birds and mammals combined. This study also puts
2256-423: Was coined in 1957 by the biologist Julian Huxley to refer to the result of cladogenesis , the evolutionary splitting of a parent species into two distinct species, a concept Huxley borrowed from Bernhard Rensch . Many commonly named groups – rodents and insects , for example – are clades because, in each case, the group consists of a common ancestor with all its descendant branches. Rodents, for example, are
2304-451: Was defined by Ketchum and Benson as " Leptocleidus superstes , Polycotylus latipinnis , their most recent common ancestor and all of its descendants". [REDACTED] [REDACTED] [REDACTED] This article about a plesiosaur is a stub . You can help Misplaced Pages by expanding it . Clade In biological phylogenetics , a clade (from Ancient Greek κλάδος (kládos) 'branch'), also known as
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