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66-565: 35, see text Opilio is a genus of harvestmen with 35 known species. The genus name is derived from Latin opilio "sheep-master" (a kind of slave), used by Plautus , also used by Virgil with the meaning "shepherd". Opilio contains the following thirty-five species: Harvestmen The Opiliones (formerly Phalangida) are an order of arachnids , colloquially known as harvestmen , harvesters , harvest spiders , or daddy longlegs . As of July 2024 , over 6,650 species of harvestmen have been discovered worldwide, although

132-490: A nauplius , which is characterized by its use of antennae for swimming. Barnacles , a highly modified crustacean, use their antennae to attach to rocks and other surfaces. The second antennae in the burrowing Hippoidea and Corystidae have setae that interlock to form a tube or "snorkel" which funnels filtered water over the gills. Some claim insects evolved from prehistoric crustaceans, and they have secondary antennae like crustaceans, but not primary antennae. Antennae are

198-456: A pre-Linnaean work). In England, the Opiliones are called harvestmen, not because they appear at that season, but from a superstitious belief that if one is killed there will be a bad harvest that year. The interfamilial relationships within Opiliones are not yet fully resolved, although significant strides have been made in recent years to determine these relationships. The following list

264-618: A broad range is unusual in arachnids, which are typically pure predators. Most hunting harvestmen ambush their prey, although active hunting is also found. Because their eyes cannot form images, they use their second pair of legs as antennae to explore their environment. Unlike most other arachnids, harvestmen do not have a sucking stomach or a filtering mechanism. Rather, they ingest small particles of their food, thus making them vulnerable to internal parasites such as gregarines . Although parthenogenetic species do occur, most harvestmen reproduce sexually . Except from small fossorial species in

330-407: A distance. The Opiliones are known for having exceptionally long legs relative to their body size; however, some species are short-legged. As in all Arachnida, the body in the Opiliones has two tagmata , the anterior cephalothorax or prosoma , and the posterior 10-segmented abdomen or opisthosoma . The most easily discernible difference between harvestmen and spiders is that in harvestmen,

396-456: A further defence from predators because they can twitch for 60 seconds to an hour after detachment. This can also potentially serve as deflection from an attack and deceive a predator from attacking the animal. It has been shown to be successful against ants and spiders. The legs continue to twitch after they are detached because 'pacemakers' are located in the ends of the first long segment (femur) of their legs. These pacemakers send signals via

462-419: A host plant's taste and odor. After the desired taste and odor has been identified, the female moth will deposit her eggs onto the plant. Giant swallowtail butterflies also rely on antenna sensitivity to volatile compounds to identify host plants. It was found that females are actually more responsive with their antenna sensing, most likely because they are responsible for oviposition on the correct plant. In

528-740: A long period. Indeed, one species discovered in China, Mesobunus martensi , fossilized by fine-grained volcanic ash around 165 million years ago, is hardly discernible from modern-day harvestmen and has been placed in the extant family Sclerosomatidae . The Swedish naturalist and arachnologist Carl Jakob Sundevall (1801–1875) honored the naturalist Martin Lister (1638–1712) by adopting Lister's term Opiliones for this order, known in Lister's days as "harvest spiders" or "shepherd spiders", from Latin opilio , "shepherd"; Lister characterized three species from England (although not formally describing them, being

594-428: A pair median eyes also have two sets of vestigial eyes: one median pair (homologous to those of horseshoe crabs and sea spiders ), and one lateral pair (homologous to facetted eyes of horseshoe crabs and insects). This discovery suggests that the neuroanatomy of harvestmen is more primitive than derived arachnid groups, like spiders and scorpions. It also showed that the four-eyed fossil harvestman previously discovered

660-418: A predator after direct or indirect contact, including thanatosis , freezing , bobbing, autotomy , fleeing, stridulation , retaliation and chemical secretions. Some animals respond to attacks by simulating an apparent death to avoid either detection or further attacks. Arachnids such as spiders practise this mechanism when threatened or even to avoid being eaten by female spiders after mating. Thanatosis

726-617: A predator. Armored harvestmen in Laniatores can often use their modified morphology as weapons. Many have spines on their pedipalps, back legs, or bodies. By pinching with their chelicerae and pedipalps, they can cause harm to a potential predator. Also this has been proven to increase survival against recluse spiders by causing injury, allowing the harvestman to escape from predation. Harvestmen are well known for being chemically protected. They exude strongly odored secretions from their scent glands, called ozopores , that act as

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792-440: A raised portion of the insect's head capsule. The socket is closed off by the membrane into which the base of the scape is set. However, the antenna does not hang free on the membrane, but pivots on a rigidly sprung projection from the rim of the torulus. That projection on which the antenna pivots is called the antennifer . The whole structure enables the insect to move the antenna as a whole by applying internal muscles connected to

858-514: A scientifically neglected group. Description of new taxa has always been dependent on the activity of a few dedicated taxonomists. Carl Friedrich Roewer described about a third (2,260) of today's known species from the 1910s to the 1950s, and published the landmark systematic work Die Weberknechte der Erde (Harvestmen of the World) in 1923, with descriptions of all species known to that time. Other important taxonomists in this field include: Since

924-516: A shield against predators; this is the most effective defense they use which creates a strong and unpleasant taste. In Cyphophthalmi the scent glands release naphthoquinones, chloro-naphthoquinones and aliphatic methyl ketones, Insidiatores use nitrogen-containing substances, terpenes, aliphatic ketones, and phenolics, while Grassatores use alkylated phenolics and benzoquinones, and Palpatores use substances like naphthoquinones, methyl- and ethyl-ketones. These secretions have successfully protected

990-468: A unit, in spite of being articulated. However, some funicles are complex and very mobile. For example, the Scarabaeidae have lamellate antennae that can be folded tightly for safety or spread openly for detecting odours or pheromones . The insect manages such actions by changes in blood pressure, by which it exploits elasticity in walls and membranes in the funicles, which are in effect erectile. In

1056-492: A variety of primary and secondary defences against predation, ranging from morphological traits such as body armour to behavioral responses to chemical secretions. Some of these defences have been attributed and restricted to specific groups of harvestmen. Primary defences help the harvestmen avoid encountering a potential predator and include crypsis , aposematism , and mimicry . Particular patterns or colour markings on harvestmen's bodies can reduce detection by disrupting

1122-572: Is a compilation of interfamilial relationships recovered from several recent phylogenetic studies, although the placement and even monophyly of several taxa are still in question. The family Stygophalangiidae (one species, Stygophalangium karamani ) from underground waters in North Macedonia is sometimes misplaced in the Phalangioidea. It is not a harvestman. Despite their long history, few harvestman fossils are known. This

1188-423: Is considered segmented if each of the annuli is separate from those around it and has individual muscle attachments. Flagellate antennae, on the other hand, have muscle attachments only around the base, acting as a hinge for the flagellum —a flexible string of annuli with no muscle attachment. There are several notable non-sensory uses of antennae in crustaceans. Many crustaceans have a mobile larval stage called

1254-495: Is formed by extensions of the coxae of the pedipalps and the first pair of legs. Most Opiliones, except for Cyphophthalmi, have long been thought to have a single pair of camera-type eyes in the middle of the head, oriented sideways. Eyes in Cyphophthalmi, when present, are located laterally, near the ozopores. A 305-million-year-old fossilized harvestman with two pairs of eyes was reported in 2014. This find suggested that

1320-522: Is in rainforest patches in northwest Argentina which are in an area being dramatically destroyed by humans. The cave-living Picunchenops spelaeus is apparently endangered through human action. So far, no harvestman has been included in any kind of a Red List in Argentina, so they receive no protection. Maiorerus randoi has only been found in one cave in the Canary Islands . It is included in

1386-513: Is mainly due to their delicate body structure and terrestrial habitat, making them unlikely to be found in sediments. As a consequence, most known fossils have been preserved within amber . The oldest known harvestman, from the 410-million-year-old Devonian Rhynie chert, displayed almost all the characteristics of modern species, placing the origin of harvestmen in the Silurian , or even earlier. A recent molecular study of Opiliones, however, dated

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1452-404: Is most likely a member of the suborder Eupnoi (true daddy-longlegs). Harvestmen have a pair of prosomatic defensive scent glands ( ozopores ) that secrete a peculiar-smelling fluid when disturbed. In some species, the fluid contains noxious quinones . They do not have book lungs , and breathe through tracheae . A pair of spiracles is located between the base of the fourth pair of legs and

1518-495: Is seen with multiple long-legged species in the Leiobunum clade that either drop and run, or drop and remain motionless. This is also seen when disturbing an aggregation of multiple individuals, where they all scatter. Multiple species within the Laniatores and Dyspnoi possess stridulating organs, which are used as intraspecific communication and have also been shown to be used as a second line of defense when restrained by

1584-452: Is the voluntary amputation of an appendage and is employed to escape when restrained by a predator. Eupnoi individuals, more specifically sclerosomatid harvestmen, commonly use this strategy in response to being captured. This strategy can be costly because harvestmen do not regenerate their legs, and leg loss reduces locomotion, speed, climbing ability, sensory perception, food detection, and territoriality. Autotomised legs provide

1650-617: Is thought to be commonly used during daylight, when they could be easily seen by any predators. Other harvestmen may exhibit mimicry to resemble other species' appearances. Some Gonyleptidae individuals that produce translucid secretions have orange markings on their carapaces . This may have an aposematic role by mimicking the colouration of glandular emissions of two other quinone-producing species. Mimicry ( Müllerian mimicry ) occurring between Brazilian harvestmen that resemble others could be explained by convergent evolution . Secondary defences allow for harvestmen to escape and survive from

1716-599: Is used as a second line of defence when detected by a potential predator and is commonly observed within the Dyspnoi and Laniatores suborders, with individuals becoming rigid with legs either retracted or stretched. Freezing – or the complete halt of movement – has been documented in the family Sclerosomatidae. While this can mean an increased likelihood of immediate survival, it also leads to reduced food and water intake. To deflect attacks and enhance escape, long-legged species – commonly known as daddy long-legs – from

1782-801: The Cenozoic , three from the Mesozoic , and at least seven from the Paleozoic . Antenna (biology) Antennae are connected to the first one or two segments of the arthropod head. They vary widely in form but are always made of one or more jointed segments. While they are typically sensory organs , the exact nature of what they sense and how they sense it is not the same in all groups. Functions may variously include sensing touch , air motion, heat, vibration (sound), and especially smell or taste . Antennae are sometimes modified for other purposes, such as mating, brooding, swimming, and even anchoring

1848-479: The Coleoptera and Hymenoptera. They are important for insects like ants that follow scent trails, for bees and wasps that need to "sniff" the flowers that they visit, and for beetles such as Scarabaeidae and Curculionidae that need to fold their antennae away when they self-protectively fold up all their limbs in defensive attitudes. Because the funicle is without intrinsic muscles, it generally must move as

1914-516: The Devonian Rhynie chert , 410 million years ago, already show characteristics like tracheae and sexual organs, indicating that the group has lived on land since that time. Despite being similar in appearance to, and often confused with, spiders, they are probably closely related to the scorpions , pseudoscorpions , and solifuges ; these four orders form the clade Dromopoda . The Opiliones have remained almost unchanged morphologically over

1980-610: The Eupnoi suborder, use two mechanisms. One is bobbing, for which these particular individuals bounce their bodies. It potentially serves to confuse and deflect any identification of the exact location of their bodies. This can be a deceiving mechanism to avoid predation when they are in a large aggregation of individuals, which are all trembling at the same time. Cellar spiders ( Pholcidae ) that are commonly mistaken for daddy long-legs (Opiliones) also exhibit this behavior when their webs are disturbed or even during courtship. Autotomy

2046-585: The Hexapoda , both Collembola and Diplura have antenna, but Protura do not. Antennal fibrillae play an important role in Culex pipiens mating practices. The erection of these fibrillae is considered to be the first stage in reproduction. These fibrillae serve different functions across the sexes. As antennal fibrillae are used by female C. pipiens to locate hosts to feed on, male C. pipiens utilize them to locate female mates. The three basic segments of

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2112-579: The Laniatores , and more than 70,000 in certain Eupnoi . Gregarious behavior is likely a strategy against climatic odds, but also against predators, combining the effect of scent secretions, and reducing the probability of any particular individual being eaten. Harvestmen clean their legs after eating by drawing each leg in turn through their jaws. Predators of harvestmen include a variety of animals, including some mammals, amphibians, and other arachnids like spiders and scorpions. Opiliones display

2178-442: The antennal lobe in the brain . From there, neurons in the antennal lobes connect to mushroom bodies that identify the odour. The sum of the electrical potentials of the antennae to a given odour can be measured using an electroantennogram . In the monarch butterfly , antennae are necessary for proper time-compensated solar compass orientation during migration. Antennal clocks exist in monarchs, and they are likely to provide

2244-907: The chelicerates and proturans , which have none, all non-crustacean arthropods have a single pair of antennae. Crustaceans bear two pairs of antennae. The pair attached to the first segment of the head are called primary antennae or antennules . This pair is generally uniramous, but is biramous in crabs and lobsters and remipedes . The pair attached to the second segment are called secondary antennae or simply antennae . The second antennae are plesiomorphically biramous, but many species later evolved uniramous pairs. The second antennae may be significantly reduced (e.g. remipedes) or apparently absent (e.g. barnacles ). The subdivisions of crustacean antennae have many names, including flagellomeres (a shared term with insects), annuli, articles, and segments. The terminal ends of crustacean antennae have two major categorizations: segmented and flagellate. An antenna

2310-473: The leaf litter found in their environments. Some hard-bodied harvestmen have epizoic cyanobacteria and liverworts growing on their bodies that suggest potential benefits for camouflage against large backgrounds to avoid detection by diurnal predators. Some harvestmen have elaborate and brightly coloured patterns or appendages which contrast with the body colouration, potentially serving as an aposematic warning to potential predators. This mechanism

2376-573: The scutum , which in most such species is fused with the carapace . Some such Opiliones only have this shield in the males. In some species, the two posterior abdominal segments are reduced. Some of them are divided medially on the surface to form two plates beside each other. The second pair of legs is longer than the others and function as antennae or feelers. In short-legged species, this may not be obvious. The feeding apparatus ( stomotheca ) differs from most arachnids in that Opiliones can swallow chunks of solid food, not only liquids. The stomotheca

2442-486: The 1990s, study of the biology and ecology of harvestmen has intensified, especially in South America . Early work on the developmental biology of Opiliones from the mid-20th century was resurrected by Prashant P. Sharma , who established Phalangium opilio as a model system for the study of arachnid comparative genomics and evolutionary-developmental biology . Harvestmen are ancient arachnids . Fossils from

2508-548: The Arachnida is disputed; their closest relatives may be camel spiders (Solifugae) or a larger clade comprising horseshoe crabs, Ricinulei, and Arachnopulmonata (scorpions, pseudoscorpions, and Tetrapulmonata). Although superficially similar to and often misidentified as spiders (order Araneae ), the Opiliones are a distinct order that is not closely related to spiders. They can be easily distinguished from long-legged spiders by their fused body regions and single pair of eyes in

2574-563: The Brazilian national list of endangered species, all of them cave-dwelling: Giupponia chagasi , Iandumoema uai , Pachylospeleus strinatii and Spaeleoleptes spaeleus . Several Opiliones in Argentina appear to be vulnerable, if not endangered. These include Pachyloidellus fulvigranulatus , which is found only on top of Cerro Uritorco , the highest peak in the Sierras Chicas chain (provincia de Cordoba) and Pachyloides borellii

2640-840: The Catálogo Nacional de especies amenazadas (National catalog of threatened species) from the Spanish government. Texella reddelli and Texella reyesi are listed as endangered species in the United States. Both are from caves in central Texas . Texella cokendolpheri from a cave in central Texas and Calicina minor , Microcina edgewoodensis , Microcina homi , Microcina jungi , Microcina leei , Microcina lumi , and Microcina tiburona from around springs and other restricted habitats of central California are being considered for listing as endangered species, but as yet receive no protection. An urban legend claims that

2706-406: The abdomen, with one opening on each side. In more active species, spiracles are also found upon the tibia of the legs. They have a gonopore on the ventral cephalothorax, and the copulation is direct as male Opiliones have a penis , unlike other arachnids. All species lay eggs . Typical body length does not exceed 7 mm (0.28 in), and some species are smaller than 1 mm, although

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2772-500: The animals' outlines or providing camouflage. Markings on legs can cause an interruption of the leg outline and loss of leg proportion recognition. Darker colourations and patterns function as camouflage when they remain motionless. Within the genus Leiobunum are multiple species with cryptic colouration that changes over ontogeny to match the microhabitat used at each life stage. Many species have also been able to camouflage their bodies by covering with secretions and debris from

2838-570: The arthropod to a substrate . Larval arthropods have antennae that differ from those of the adult. Many crustaceans, for example, have free-swimming larvae that use their antennae for swimming. Antennae can also locate other group members if the insect lives in a group, like the ant . The common ancestor of all arthropods likely had one pair of uniramous (unbranched) antenna-like structures, followed by one or more pairs of biramous (having two major branches) leg-like structures, as seen in some modern crustaceans and fossil trilobites . Except for

2904-421: The connection between the cephalothorax and abdomen is broad, so that the body appears to be a single oval structure. Other differences include the fact that Opiliones have no venom glands in their chelicerae and thus pose no danger to humans. They also have no silk glands and therefore do not build webs. In some highly derived species, the first five abdominal segments are fused into a dorsal shield called

2970-416: The crane flies of the superfamily Tipuloidea , and the cellar spiders of the family Pholcidae, (commonly referred to as "daddy long-leg spiders") most likely because of their similar appearance. Harvestmen are also referred to as "shepherd spiders" in reference to how their unusually long legs reminded observers of the ways that some European shepherds used stilts to better observe their wandering flocks from

3036-607: The crepuscular hawk moth ( Manduca sexta ), antennae aid in flight stabilization. Similar to halteres in Dipteran insects, the antennae transmit coriolis forces through the Johnston's organ that can then be used for corrective behavior. A series of low-light, flight stability studies in which moths with flagellae amputated near the pedicel showed significantly decreased flight stability over those with intact antennae. To determine whether there may be other antennal sensory inputs,

3102-609: The eyes in Cyphophthalmi are not homologous to the eyes of other harvestmen. Many cave-adapted species are eyeless, such as the Brazilian Caecobunus termitarum ( Grassatores ) from termite nests, Giupponia chagasi ( Gonyleptidae ) from caves, most species of Cyphophthalmi, and all species of the Guasiniidae . However, recent work studying the embryonic development of the species Phalangium opilio and some Laniatores revealed that harvestman in addition to

3168-457: The flagellum. Such groups include the Symphyla , Collembola and Diplura . In many true insects, especially the more primitive groups such as Thysanura and Blattodea , the flagellum partly or entirely consists of a flexibly connected string of small ring-shaped annuli . The annuli are not true flagellomeres, and in a given insect species the number of annuli generally is not as consistent as

3234-519: The funicle is taken to comprise the segments between the club and the pedicel. Quite commonly the funicle beyond the pedicel is quite complex in Endopterygota such as beetles, moths and Hymenoptera , and one common adaptation is the ability to fold the antenna in the middle, at the joint between the pedicel and the flagellum. This gives an effect like a "knee bend", and such an antenna is said to be geniculate . Geniculate antennae are common in

3300-516: The groups with more uniform antennae (for example: millipedes ), all segments are called antennomeres . Some groups have a simple or variously modified apical or subapical bristle called an arista (this may be especially well-developed in various Diptera ). Olfactory receptors on the antennae bind to free-floating molecules, such as water vapour , and odours including pheromones . The neurons that possess these receptors signal this binding by sending action potentials down their axons to

3366-490: The harvestman is the most venomous animal in the world but possesses fangs too short or a mouth too round and small to bite a human, rendering it harmless (the same myth applies to Pholcus phalangioides and the crane fly , which are both also called a "daddy longlegs"). None of the known species of harvestmen have venom glands; their chelicerae are not hollowed fangs but grasping claws that are typically very small and not strong enough to break human skin. Harvestmen are

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3432-569: The harvestmen against wandering spiders ( Ctenidae ), wolf spiders (Lycosidae) and Formica exsectoides ants. However, these chemical irritants are not able to prevent four species of harvestmen being preyed upon by the black scorpion Bothriurus bonariensis ( Bothriuridae ). These secretions contain multiple volatile compounds that vary among individuals and clades. All troglobitic species (of all animal taxa) are considered to be at least threatened in Brazil . Four species of Opiliones are on

3498-575: The largest known species, Trogulus torosus ( Trogulidae ), grows as long as 22 mm (0.87 in). The leg span of many species is much greater than the body length and sometimes exceeds 160 mm (6.3 in) and to 340 mm (13 in) in Southeast Asia. Most species live for a year. Many species are omnivorous , eating primarily small insects and all kinds of plant material and fungi . Some are scavengers , feeding upon dead organisms, bird dung, and other fecal material. Such

3564-571: The male is solely responsible for guarding the eggs resulting from multiple partners, often against egg-eating females , and cleaning the eggs regularly. Paternal care has evolved at least three times independently: once in the clade Progonyleptoidellinae + Caelopyginae, once in the Gonyleptinae, and once in the Heteropachylinae. Maternal care in opiliones probably evolved due to natural selection, while paternal care appears to be

3630-435: The males defend territories. In some species, males also exhibit post-copulatory behavior in which the male specifically seeks out and shakes the female's sensory leg. This is believed to entice the female into mating a second time. The female lays her eggs shortly after mating to several months later. Some species build nests for this purpose. A unique feature of harvestmen is that some species practice parental care, in which

3696-413: The middle of the cephalothorax . Spiders have a distinct abdomen that is separated from the cephalothorax by a constriction, and they have three to four pairs of eyes, usually around the margins of the cephalothorax. English speakers may colloquially refer to species of Opiliones as "daddy longlegs" or "granddaddy longlegs", but this name is also used for two other distantly related groups of arthropods ,

3762-424: The nerves to the muscles to extend the leg and then the leg relaxes between signals. While some harvestman's legs twitch for a minute, others have been recorded to twitch up to an hour. The twitching has been hypothesised to function as an evolutionary advantage by keeping the attention of a predator while the harvestman escapes. Individuals that are able to detect potential threats can flee rapidly from attack. This

3828-421: The number of flagellomeres in most species. In many beetles and in the chalcidoid wasps , the apical flagellomeres form a club shape, called the clava . The collective term for the segments between the club and the antennal base is the funicle ; traditionally in describing beetle anatomy, the term "funicle" refers to the segments between the club and the scape . However, traditionally in working on wasps

3894-584: The origin of the order at about 473 million years ago (Mya), during the Ordovician. No fossils of the Cyphophthalmi or Laniatores much older than 50 million years are known, despite the former presenting a basal clade , and the latter having probably diverged from the Dyspnoi more than 300 Mya. Naturally, most finds are from comparatively recent times. More than 20 fossil species are known from

3960-414: The primary olfactory sensors of insects and are accordingly well-equipped with a wide variety of sensilla (singular: sensillum ). Paired, mobile, and segmented, they are located between the eyes on the forehead. Embryologically, they represent the appendages of the second head segment. All insects have antennae, however they may be greatly reduced in the larval forms. Amongst the non-insect classes of

4026-482: The primary timing mechanism for sun compass orientation. In the African cotton leafworm , antennae have an important function in signaling courtship. Specifically, antennae are required for males to answer the female mating call. Although females do not require antennae for mating, a mating that resulted from a female without antennae was abnormal. In the diamondback moth , antennae serve to gather information about

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4092-746: The result of sexual selection. Depending on circumstances such as temperature, the eggs may hatch at any time after the first 20 days, up to about half a year after being laid. Harvestmen variously pass through four to eight nymphal instars to reach maturity, with most known species having six instars. Most species are nocturnal and colored in hues of brown, although a number of diurnal species are known, some of which have vivid patterns in yellow, green, and black with varied reddish and blackish mottling and reticulation. Many species of harvestmen easily tolerate members of their own species, with aggregations of many individuals often found at protected sites near water. These aggregations may number 200 individuals in

4158-514: The scape. The pedicel is flexibly connected to the distal end of the scape and its movements in turn can be controlled by muscular connections between the scape and pedicel. The number of flagellomeres can vary greatly between insect species, and often is of diagnostic importance. True flagellomeres are connected by membranous linkage that permits movement, though the flagellum of "true" insects does not have any intrinsic muscles. Some other Arthropoda do however have intrinsic muscles throughout

4224-437: The suborder Cyphophthalmi, where the males deposit a spermatophore , mating involves direct copulation. The females store the sperm, which is aflagellate and immobile, at the tip of her ovipositor. The eggs are fertilized during oviposition. The males of some species offer a secretion (nuptial gift) from their chelicerae to the female before copulation. Sometimes, the male guards the female after copulation, and in many species,

4290-696: The total number of extant species may exceed 10,000. The order Opiliones includes five suborders: Cyphophthalmi , Eupnoi , Dyspnoi , Laniatores , and Tetrophthalmi , which were named in 2014. Representatives of each extant suborder can be found on all continents except Antarctica . Well-preserved fossils have been found in the 400-million-year-old Rhynie cherts of Scotland, and 305-million-year-old rocks in France. These fossils look surprisingly modern, indicating that their basic body shape developed very early on, and, at least in some taxa, has changed little since that time. Their phylogenetic position within

4356-464: The typical insect antenna are the scape or scapus (base), the pedicel or pedicellus (stem), and finally the flagellum , which often comprises many units known as flagellomeres . The pedicel (the second segment) contains the Johnston's organ which is a collection of sensory cells. The scape is mounted in a socket in a more or less ring-shaped sclerotised region called the torulus , often

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