The Opiliones (formerly Phalangida) are an

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of ...

of arachnids colloquially known as harvestmen, harvesters, harvest spiders, or daddy longlegs. , over 6,650 species of harvestmen have been discovered worldwide, although the total number of

extant Extant is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Extant taxon, a taxon which is not extinct, ...

species may exceed 10,000. The order Opiliones includes five suborders:

Cyphophthalmi Cyphophthalmi is a suborder of harvestmen, colloquially known as mite harvestmen. Cyphophthalmi comprises 36 genera, and more than two hundred described species. The six families are currently grouped into three infraorders: the Boreophthalmi, Sc ...

, Eupnoi, Dyspnoi, Laniatores, and Tetrophthalmi, which were named in 2014. Representatives of each extant suborder can be found on all continents except

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest cont ...

. Well-preserved fossils have been found in the 400-million-year-old

Rhynie chert The Rhynie chert is a Lower Devonian sedimentary deposit exhibiting extraordinary fossil detail or completeness (a Lagerstätte). It is exposed near the village of Rhynie, Aberdeenshire, Scotland; a second unit, the Windyfield chert, is located ...

s 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 In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups ...

position within the Arachnida is disputed; their closest relatives may be the mites (

Acari Mites are small arachnids (eight-legged arthropods). Mites span two large orders of arachnids, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari, but genetic analysis does not show clear evid ...

) or the Novogenuata (the Scorpiones, Pseudoscorpiones, and

Solifugae Solifugae is an order of animals in the class Arachnida known variously as camel spiders, wind scorpions, sun spiders, or solifuges. The order includes more than 1,000 described species in about 147 genera. Despite the common names, they are ne ...

). Although superficially similar to and often misidentified as

spider Spiders (order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species ...

s (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 the middle of the

cephalothorax The cephalothorax, also called prosoma in some groups, is a tagma of various arthropods, comprising the head and the thorax fused together, as distinct from the abdomen behind. (The terms ''prosoma'' and ''opisthosoma'' are equivalent to ''cepha ...

. 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

arthropod Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and cuticle made of chiti ...

s, the crane flies of the family Tipulidae, and the cellar spiders of the family Pholcidae, 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 a distance.

Description

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 Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek language, Greek roots, describe something in its standard anatomical position. Th ...

prosoma The cephalothorax, also called prosoma in some groups, is a tagma of various arthropods, comprising the head and the thorax fused together, as distinct from the abdomen behind. (The terms ''prosoma'' and ''opisthosoma'' are equivalent to ''cepha ...

, and the posterior 10-segmented

abdomen The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the to ...

opisthosoma The opisthosoma is the posterior part of the body in some arthropods, behind the prosoma (cephalothorax). It is a distinctive feature of the subphylum Chelicerata (arachnids, horseshoe crabs and others). Although it is similar in most respects to ...

. The most easily discernible difference between harvestmen and spiders is that in harvestmen, 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 Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a st ...

glands in their chelicerae, so 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 the

scutum The ''scutum'' (; plural ''scuta'') was a type of shield used among Italic peoples in antiquity, most notably by the army of ancient Rome starting about the fourth century BC. The Romans adopted it when they switched from the military formatio ...

, which in most such species is fused with the

carapace A carapace is a dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tortoises, the unde ...

. 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 Stomotheca is the term applied to the feeding apparatus in front of the mouth of harvestmen, and sometimes the related scorpions. Usually it consists of the ''epistome'' (labrum), two pairs of ''coxapophyses'' (endites, maxillary lobes) and often a ...

) differs from most arachnids in that Opiliones can swallow chunks of solid food, not only liquids. The stomotheca is formed by extensions of the coxae of the pedipalps and the first pair of legs. Most Opiliones, except for Cyphophthalmi, have a single pair of 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 indicates that the eyes in Cyphophthalmi are not homologous to the eyes of other harvestmen. However, some species are eyeless, such as the Brazilian '' Caecobunus termitarum'' ( Grassatores) from

termite Termites are small insects that live in colonies and have distinct castes ( eusocial) and feed on wood or other dead plant matter. Termites comprise the infraorder Isoptera, or alternatively the epifamily Termitoidae, within the order Blat ...

nests, '' Giupponia chagasi'' ( Gonyleptidae) from caves, most species of Cyphophthalmi, and all species of the Guasiniidae. Harvestman macro

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 The quinones are a class of organic compounds that are formally "derived from aromatic compounds uch as benzene or naphthalene">benzene.html" ;"title="uch as benzene">uch as benzene or naphthalene] by conversion of an even number of –CH= grou ...

. They do not have

book lungs A book lung is a type of respiration organ used for atmospheric gas exchange that is present in many arachnids, such as scorpions and spiders. Each of these organs is located inside an open ventral abdominal, air-filled cavity (atrium) and conn ...

, and breathe through

tracheae The trachea, also known as the windpipe, is a cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all air-breathing animals with lungs. The trachea extends from the la ...

. A pair of spiracles is located between the base of the fourth pair of legs and the abdomen, with one opening on each side. In more active species, spiracles are also found upon the

tibia The tibia (; ), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outside of the tibia); it conn ...

of the legs. They have a gonopore on the ventral cephalothorax, and the

copulation Sexual intercourse (or coitus or copulation) is a sexual activity typically involving the insertion and thrusting of the penis into the vagina for sexual pleasure or reproduction.Sexual intercourse most commonly means penile–vaginal penetra ...

is direct as male Opiliones have a penis, unlike other arachnids. All species lay eggs. Typical body length does not exceed , and some species are smaller than 1 mm, although the largest known species, '' Trogulus torosus'' ( Trogulidae), grows as long as . The leg span of many species is much greater than the body length and sometimes exceeds and to in Southeast Asia. Most species live for a year.

Behavior

Harvestman Opiliones grooming 2016-05-15

Many species are omnivorous, eating primarily small

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pa ...

s and all kinds of plant material and

fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately fr ...

. Some are

scavenger Scavengers are animals that consume dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a herbivorous feedin ...

s, feeding upon dead organisms, bird dung, and other fecal material. Such 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

gregarine The gregarines are a group of Apicomplexan alveolates, classified as the Gregarinasina or Gregarinia. The large (roughly half a millimeter) parasites inhabit the intestines of many invertebrates. They are not found in any vertebrates. However, g ...

s. Although

parthenogenetic Parthenogenesis (; from the Greek grc, παρθένος, translit=parthénos, lit=virgin, label=none + grc, γένεσις, translit=génesis, lit=creation, label=none) is a natural form of asexual reproduction in which growth and development ...

species do occur, most harvestmen reproduce sexually. Mating involves direct copulation, rather than the deposition of a

spermatophore A spermatophore or sperm ampulla is a capsule or mass containing spermatozoa created by males of various animal species, especially salamanders and arthropods, and transferred in entirety to the female's ovipore during reproduction. Spermatophore ...

. 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, 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 females lay eggs from an ovipositor 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 the male is solely responsible for guarding the eggs resulting from multiple partners, often against egg-eating females, and cleaning the eggs regularly. 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

instar An instar (, from the Latin '' īnstar'', "form", "likeness") is a developmental stage of arthropods, such as insects, between each moult (''ecdysis''), until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or ...

s to reach maturity, with most known species having six instars. Most species are

nocturnal Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed sens ...

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 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.

Antipredator defenses

Predators of harvestmen include a variety of animals, including some mammals, amphibians, and other arachnids like spiders and scorpions. Opiliones display a variety of primary and secondary defenses against predation, ranging from morphological traits such as body armor to behavioral responses to chemical secretions. Some of these defenses have been attributed and restricted to specific groups of harvestmen.

Primary defenses

Primary defenses help the harvestmen avoid encountering a potential predator, and include

crypsis In ecology, crypsis is the ability of an animal or a plant to avoid observation or detection by other animals. It may be a predation strategy or an antipredator adaptation. Methods include camouflage, nocturnality, subterranean lifestyle an ...

aposematism Aposematism is the advertising by an animal to potential predators that it is not worth attacking or eating. This unprofitability may consist of any defences which make the prey difficult to kill and eat, such as toxicity, venom, foul taste ...

, and

mimicry In evolutionary biology, mimicry is an evolved resemblance between an organism and another object, often an organism of another species. Mimicry may evolve between different species, or between individuals of the same species. Often, mimicry f ...

Crypsis

Particular patterns or color markings on harvestmen's bodies can reduce detection by disrupting the animals' outlines or providing camouflage. Markings on legs can cause an interruption of the leg outline and loss of leg proportion recognition. Darker colorations and patterns function as

camouflage Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the b ...

when they remain motionless.Gnaspini, P., Cavalheiro, A.J., 1998. Chemical and Behavioral Defenses of a Neotropical Cavernicolous Harvestman: Goniosoma spelaeum (Opiliones, Laniatores, Gonyleptidae). J. Arachnol. 26, 81–90. Within the genus '' Leiobunum'' are multiple species with cryptic coloration 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 the leaf litter found in their environments. Some hard-bodied harvestmen have epizoic

cyanobacteria Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, bl ...

and

liverworts The Marchantiophyta () are a division of non-vascular land plants commonly referred to as hepatics or liverworts. Like mosses and hornworts, they have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of ...

growing on their bodies that suggest potential benefits for camouflage against large backgrounds to avoid detection by diurnal predators.

Aposematism and mimicry

Some harvestmen have elaborate and brightly colored patterns or appendages which contrast with the body coloration, potentially serving as an aposematic warning to potential predators.González, A., Rossini, C., Eisner, T., 2004. Mimicry: imitative depiction of discharged defensive secretion on carapace of an opilionid. CHEMOECOLOGY 14, 5–7.Pomini, A.M., Machado, G., Pinto-da-Rocha, R., Macías-Ordóñez, R., Marsaioli, A.J., 2010. Lines of defense in the harvestman Hoplobunus mexicanus (Arachnida: Opiliones): Aposematism, stridulation, thanatosis, and irritant chemicals. Biochem. Syst. Ecol. 38, 300–308. This mechanism 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

s. This may have an aposematic role by mimicking the coloration 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 Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last com ...

Secondary defenses

Secondary defenses allow for harvestmen to escape and survive from a predator after direct or indirect contact, including thanatosis,

freezing Freezing is a phase transition where a liquid turns into a solid when its temperature is lowered below its freezing point. In accordance with the internationally established definition, freezing means the solidification phase change of a liquid ...

, bobbing,

autotomy Autotomy (from the Greek ''auto-'', "self-" and ''tome'', "severing", αὐτοτομία) or self-amputation, is the behaviour whereby an animal sheds or discards one or more of its own appendages, usually as a self-defense mechanism to elude ...

, fleeing, stridulation,

retaliation Revenge is committing a harmful action against a person or group in response to a grievance, be it real or perceived. Francis Bacon described revenge as a kind of "wild justice" that "does... offend the law ndputteth the law out of office." Pr ...

, and chemical secretions.

Thanatosis

Some animals respond to attacks by simulating an apparent death to avoid either detection or further attacks. Arachnids such as spiders practice this mechanism when threatened or even to avoid being eaten by female spiders after mating. Thanatosis is used as a second line of defense 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.Eisner, T., Alsop, D., Meinwald, J., 1978. Secretions of Opilionids, Whip Scorpions and Pseudoscorpions, in: Arthropod Venoms, Handbook of Experimental Pharmacology / Handbuch Der Experimentellen Pharmakologie. Springer, Berlin, Heidelberg, pp. 87–99.Machado, G., Pomini, A.M., 2008. Chemical and behavioral defenses of the neotropical harvestman Camarana flavipalpi (Arachnida: Opiliones). Biochem. Syst. Ecol. 36, 369–376.

Freezing

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.Chelini, M.-C., Willemart, R.H., Hebets, E.A., 2009. Costs and benefits of freezing behaviour in the harvestman Eumesosoma roeweri (Arachnida, Opiliones). Behav. Processes 82, 153–159.

Bobbing

To deflect attacks and enhance escape, long-legged species – commonly known as daddy long-legs – from 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.Escalante, I., Albín, A., Aisenberg, A., 2013. Lacking sensory (rather than locomotive) legs affects locomotion but not food detection in the harvestman Holmbergiana weyenberghi. Can. J. Zool. 91, 726–731. 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

Autotomy is the voluntary amputation of an appendage, and is employed to escape when restrained by a predator.Roth, V.D., Roth, B.M., 1984. review of appendotomy in spiders and other arachnids. Bull.-Br. Arachnol. Soc. Eupnoi individuals, more specifically sclerosomatid harvestmen, commonly use this strategy in response to being captured.Houghton, J.E., Townsend, V.R., Proud, D.N., 2011. The Ecological Significance of Leg Autotomy for Climbing Temperate Species of Harvestmen (Arachnida, Opiliones, Sclerosomatidae). Southeast. Nat. 10, 579–590.Guffey, C., 1998. Leg Autotomy and Its Potential Fitness Costs for Two Species of Harvestmen (Arachnida, Opiliones). J. Arachnol. 26, 296–302. 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. Autotomized legs provide a further defense 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 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 hypothesized to function as an evolutionary advantage by keeping the attention of a predator while the harvestman escapes.

Fleeing

Individuals that are able to detect potential threats can flee rapidly from attack. This 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.

Stridulation

Multiple species within the Laniatores and Dyspnoi possess

stridulating Stridulation is the act of producing sound by rubbing together certain body parts. This behavior is mostly associated with insects, but other animals are known to do this as well, such as a number of species of fish, snakes and spiders. The mech ...

organs, which are used as

intraspecific communication Animal communication is the transfer of information from one or a group of animals (sender or senders) to one or more other animals (receiver or receivers) that affects the current or future behavior of the receivers. Information may be sent int ...

and have also been shown to be used as a second line of defense when restrained by a predator.

Retaliation

Armored harvestmen in Laniatores can often use their modified morphology as weapons.Dias, B.C., Willemart, R.H., 2013. The effectiveness of post-contact defenses in a prey with no pre-contact detection. Zoology 116, 168–174.Segovia, J.M.G., Del-Claro, K., Willemart, R.H., 2015. Defences of a Neotropical harvestman against different levels of threat by the recluse spider. Behaviour 152, 757–773. 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.

Chemical

Harvestmen are well known for being chemically protected. They exude strongly odored secretions from their scent glands, called ozopores, that act as 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, and naphthoquinones. These secretions have successfully protected 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 ''Bothriurus'' is a genus of Neotropical scorpion Scorpions are predatory arachnids of the order Scorpiones. They have eight legs, and are easily recognized by a pair of grasping pincers and a narrow, segmented tail, often carried in a cha ...

bonariensis'' (

Bothriuridae The Bothriuridae are a family of scorpion Scorpions are predatory arachnids of the order Scorpiones. They have eight legs, and are easily recognized by a pair of grasping pincers and a narrow, segmented tail, often carried in a characteris ...

). These secretions contain multiple volatile compounds that vary among individuals and clades.

Endangered status

All troglobitic species (of all animal taxa) are considered to be at least threatened in

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

. Four species of Opiliones are on 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'' 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 The Canary Islands (; es, :es:Canarias, Canarias, ), also known informally as the Canaries, are a Spanish Autonomous communities of Spain, autonomous community and archipelago in the Atlantic Ocean, in Macaronesia. At their closest point to ...

. It is included in the Catálogo Nacional de especies amenazadas (National catalog of threatened species) from the Spanish government. ''

Texella reddelli ''Texella reddelli'', the Bee Creek cave harvestman, is a rare species of troglobitic harvestman that was added to the United States endangered species list in 1988, at the same time as six other species native to the karst ecosystem in Travis Co ...

'' and ''

Texella reyesi ''Texella reyesi'' is a rare species of arachnid known by the common name Bone Cave harvestman. It is endemic to Texas in the United States, where it lives in limestone caves in Travis and Williamson Counties. It is threatened by the loss of it ...

'' are listed as endangered species in the United States. Both are from caves in central

Texas Texas (, ; Spanish: ''Texas'', ''Tejas'') is a state in the South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by ...

. '' 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 California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

are being considered for listing as endangered species, but as yet receive no protection.

Misconception

urban legend An urban legend (sometimes contemporary legend, modern legend, urban myth, or urban tale) is a genre of folklore comprising stories or fallacious claims circulated as true, especially as having happened to a "friend of a friend" or a family m ...

claims that the harvestman is the most

ous 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 ''Pholcus phalangioides'', commonly known as daddy long-legs spider or long-bodied cellar spider, is a spider of the family Pholcidae. It is also known as the skull spider, since its cephalothorax resembles a human skull. This is the only spide ...

'' and the cranefly, which are both also called a "daddy longlegs"). This is untrue on several counts. 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.

Research

Harvestmen are a scientifically neglected group. Description of new taxa has always been dependent on the activity of a few dedicated taxonomists.

Carl Friedrich Roewer Carl Friedrich Roewer (12 October 1881, in Neustrelitz – 17 June 1963) was a German arachnologist. He concentrated on harvestmen, where he described almost a third (2,260) of today's known species, but also almost 700 taxa of spiders and num ...

described about a third (2,260) of today's known species from the 1910s to the 1950s, and published the landmark systematic work (Harvestmen of the World) in 1923, with descriptions of all species known to that time. Other important taxonomists in this field include: * Pierre Latreille (18th century) *

Carl Ludwig Koch Carl Ludwig Koch (21 September 1778 – 23 August 1857) was a German entomologist and arachnologist. He was responsible for classifying a great number of spiders, including the Brazilian whiteknee tarantula and common house spider. He was b ...

Maximilian Perty Josef Anton Maximilian Perty (17 September 1804, Ornbau – 8 August 1884, Bern) was a German naturalist and entomologist. He was a professor of zoology and comparative anatomy at the University of Bern.L. Koch,

Tord Tamerlan Teodor Thorell Tord Tamerlan Teodor Thorell (3 May 1830 – 22 December 1901) was a Swedish arachnologist. Thorell studied spiders with Giacomo Doria at the Museo Civico di Storia Naturale de Genoa. He corresponded with other arachnologists, such as Octaviu ...

(1860s–1870s) *

Eugène Simon Eugène Louis Simon (; 30 April 1848 – 17 November 1924) was a French naturalist who worked particularly on insects and spiders, but also on birds and plants. He is by far the most prolific spider taxonomist in history, describing over 4 ...

, William Sørensen (1880s–1890s) *James C. Cokendolpher, Raymond Forster, Clarence and Marie Goodnight, Jürgen Gruber, Reginald Frederick Lawrence, Jochen Martens,

Cândido Firmino de Mello-Leitão Cândido Firmino de Mello-Leitão (July 17, 1886 – December 14, 1948) was a Brazilian zoologist who is considered the founder of Arachnology in South America, publishing 198 papers on the taxonomy of Arachnida. He was also involved with edu ...

(20th century) *

Gonzalo Giribet Gonzalo Giribet is a Spanish-American invertebrate zoologist and Alexander Agassiz Professor of zoology working on systematics and biogeography at the Museum of Comparative Zoology in Harvard University. He is a past president of the Internationa ...

, Adriano Brilhante Kury, Tone Novak (21st century) Since the 1990s, study of the biology and ecology of harvestmen has intensified, especially in

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sou ...

Phylogeny

Harvestmen are ancient arachnids. Fossils from the

Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, wh ...

, 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

scorpion Scorpions are predatory arachnids of the order Scorpiones. They have eight legs, and are easily recognized by a pair of grasping pincers and a narrow, segmented tail, often carried in a characteristic forward curve over the back and always en ...

pseudoscorpion Pseudoscorpions, also known as false scorpions or book scorpions, are small, scorpion-like arachnids belonging to the order Pseudoscorpiones, also known as Pseudoscorpionida or Chelonethida. Pseudoscorpions are generally beneficial to humans sin ...

s, and solifuges; these four orders form the clade Dromopoda. The Opiliones have remained almost unchanged morphologically over 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.

Etymology

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 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 be killed there will be a bad harvest that year.

Systematics

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 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. * Suborder

Simon 1879 (about 200 species) ** Infraorder Boreophthalmi Giribet 2012 *** Family

Sironidae The Sironidae are a family of harvestmen with more than 30 described species. The family shows a Laurasian distribution, with most species found in temperate Europe and the west coast of North America. The only exception is ''Suzukielus sauter ...

Simon 1879 *** Family

Stylocellidae The Stylocellidae are a family of harvestmen with about 30 described species, all of which occur from India to New Guinea. Members of this family are from one to seven millimeters long. While ''Stylocellus'' species have eyes, these are absent ...

Hansen & Sørensen 1904 ** Infraorder Scopulophthalmi Giribet 2012 *** Family

Pettalidae The Pettalidae are a family of harvestmen with 75 described species in 10 genus, genera.Boyer & Giribet 2007 Several undescribed species are known or assumed in some genera. (2007): Pettalidae Shear, 1980. In: Pinto-da-Rocha ''et al.'' 2007: 99ff ...

Shear 1980 ** Infraorder Sternophthalmi Giribet 2012 *** Family Troglosironidae Shear 1993 *** Superfamily Ogoveoidea Shear 1980 **** Family Neogoveidae Shear 1980 **** Family Ogoveidae Shear 1980 * Suborder Eupnoi Hansen & Sørensen 1904 (about 1,800 species) ** Superfamily Caddoidea Banks 1892 *** Family

Caddidae Caddidae is a family of harvestmen arachnids with 15 known species, the only family of the Eupnoi superfamily Caddoidea. They have mostly a body length between one and three millimeters. (2007): Caddidae Banks, 1893. In: Pinto-da-Rocha ''et al.. ...

Banks 1892 *** Superfamily Phalangioidea Latreille 1802 **** Family

Neopilionidae The Neopilionidae are a family of harvestmen. It has a clearly Gondwanan distribution, with species found in Australia, South Africa and South America, and probably represent Relict (biology), relicts of that time. The family members range in s ...

Lawrence 1931 **** Family Phalangiidae Latreille 1802 **** Family Protolophidae Banks 1893 **** Family Sclerosomatidae Simon 1879 * Suborder Dyspnoi Hansen & Sørensen 1904 (about 400 species) ** Superfamily Acropsopilionoidea Roewer 1923 *** Family Acropsopilionidae Roewer 1923 ** Superfamily Ischyropsalidoidea Simon 1879 *** Family Ischyropsalididae Simon 1879 *** Family Sabaconidae Dresco 1970 *** Family Taracidae Schönhofer 2013 ** Superfamily Troguloidea Sundevall 1833 *** Family Dicranolasmatidae Simon 1879 *** Family Nemastomatidae Simon 1872 *** Family Nipponopsalididae Martens 1976 *** Family Trogulidae Sundevall 1833 * Suborder Laniatores Thorell, 1876 (about 4,200 species) ** Infraorder Insidiatores Loman, 1900 *** Superfamily

Travunioidea Travunioidea is a superfamily of armoured harvestmen in the order Opiliones The Opiliones (formerly Phalangida) are an order of arachnids colloquially known as harvestmen, harvesters, harvest spiders, or daddy longlegs. , over 6,650 species ...

Absolon & Kratochvil 1932 **** Family

Cladonychiidae The Cladonychiidae are a small family of harvestman with about 33 described species, within the suborder Laniatores. Description Members of this family range from less than two to about four millimeters in body length, with robust, spined pedip ...

Hadži 1935 **** Family Cryptomastridae Derkarabetian & Hedin 2018 **** Family Paranonychidae Briggs 1971 **** Family

Travuniidae The Travuniidae are a small family of harvestman with little more than ten described species, within the suborder Laniatores. Description Travuniidae are at the most three millimeters long, with slender, unarmed legs and robust, strongly spined ...

Absolon & Kratochvil 1932 *** Superfamily Triaenonychoidea Sørensen, 1886 **** Family Synthetonychiidae Forster 1954 **** Family

Triaenonychidae The Triaenonychidae are a family of harvestmen with about 120 genera and more than 440 described species. Description Most Triaenonychidae are from three to five millimeters long, although some species from South Africa can be only long. Some s ...

Sørensen, 1886 ** Infraorder Grassatores Kury, 2002 *** Superfamily Assamioidea Sørensen, 1884 **** Family

Assamiidae Assamiidae are a family of harvestmen with more than 400 described species. It is the third most diverse family of the suborder Laniatores. Name The family name is derived from the Indian province Assam, where the type species of the type genus ...

Sørensen, 1884 **** Family Pyramidopidae Sharma and Giribet, 2011 *** Superfamily Epedanoidea Sørensen, 1886 **** Family Epedanidae Sørensen, 1886 **** Family Petrobunidae Sharma and Giribet, 2011 **** Family Podoctidae Roewer, 1912 **** Family Tithaeidae Sharma and Giribet, 2011 *** Superfamily

Gonyleptoidea Gonyleptoidea is the most diverse superfamily of the Grassatores. It includes around 2,500 species distributed in the tropics. They are characterized by the simplified male genitalia, with the glans free subapical in the truncus. Gonyleptoidea ...

Sundevall, 1833 **** Family Agoristenidae Šilhavý, 1973 **** Family Otilioleptidae Acosta, 2019 **** Family

Cosmetidae Cosmetidae is a family of harvestmen in the suborder Laniatores. With over 700 species, it is one of the largest families in Opiliones. They are distributed from Argentina to the southern USA with the highest diversity in northern South America ...

Koch, 1839 **** Family

Cranaidae The Cranaidae are a family of neotropical harvestmen within the suborder Laniatores. Name The name of the type genus is derived from Cranaus, the successor of Cecrops I as king of Attica in Greek mythology. (2007): Cranaidae Roewer, 1913. In: Pi ...

Roewer, 1913 **** Family Cryptogeobiidae Kury, 2014 **** Family Gerdesiidae Bragagnolo, 2015 **** Family Gonyleptidae Sundevall, 1833 **** Family

Manaosbiidae The Manaosbiidae are a family of neotropical harvestmen within the suborder Laniatores. Name The name of the type genus is combined from Manaus and Ancient Greek ''bios'' "living". (2007): Manaosbiidae. Roewer, 1943. In: Pinto-da-Rocha ''et a ...

Roewer, 1943 **** Family Metasarcidae Kury, 1994 **** Family Nomoclastidae Roewer, 1943 **** Family

Stygnidae The Stygnidae are a family of Neotropics, neotropical harvestmen within the suborder Laniatores. Name The name of the type genus is derived from Ancient Greek ''stygnos'' "diabolic being". (2007): Stygnidae Simon, 1879. In: Pinto-da-Rocha ''et a ...

Simon, 1879 **** Family

Stygnopsidae The Stygnopsidae are a small family of harvestmen, with almost all species found in Mexico. Name The name of the type genus ''Stygnopsis'' is combined from the genus ''Stygnus'' (Stygnidae) and Ancient Greek ''opsis'', "looks like". (2007): Styg ...

Sørensen, 1932 *** Superfamily

Phalangodoidea The Phalangodoidea are a superfamily of the harvestman infraorder Grassatores with three recognized families and 220 species. It is not to be confused with the similarly spelled subfamily Phalangioidea, which is also a harvestman superfamily, bu ...

Simon, 1879 **** Family Phalangodidae Simon, 1879 *** Superfamily Samooidea Sørensen, 1886 **** Family Biantidae Thorell, 1889 **** Family Samoidae Sørensen, 1886 **** Family Stygnommatidae Roewer, 1923 *** Superfamily Sandokanoidea Özdikmen & Kury, 2007 **** Family Sandokanidae Özdikmen & Kury, 2007 *** Superfamily Zalmoxoidea Sørensen, 1886 **** Family Escadabiidae Kury & Pérez, 2003 **** Family Fissiphalliidae Martens, 1988 **** Family Guasiniidae Gonzalez-Sponga, 1997 **** Family Icaleptidae Kury & Pérez, 2002 **** Family Kimulidae Pérez González, Kury & Alonso-Zarazaga, 2007 **** Family Zalmoxidae Sørensen, 1886 The family Stygophalangiidae (one species, '' Stygophalangium karamani'') from underground waters in

North Macedonia North Macedonia, ; sq, Maqedonia e Veriut, (Macedonia before February 2019), officially the Republic of North Macedonia,, is a country in Southeast Europe. It gained independence in 1991 as one of the successor states of Socialist Feder ...

is sometimes misplaced in the Phalangioidea. It is not a harvestman.

Fossil record

Despite their long history, few harvestman fossils are known. This 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 Amber is fossilized tree resin that has been appreciated for its color and natural beauty since Neolithic times. Much valued from antiquity to the present as a gemstone, amber is made into a variety of decorative objects."Amber" (2004). In M ...

. 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 The Silurian ( ) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the shortest period of the Paleoz ...

, or even earlier. A recent molecular study of Opiliones, however, dated the origin of the order at about 473 million years ago (Mya), during the Ordovician. No fossils of the

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 the

Cenozoic The Cenozoic ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterised by the dominance of mammals, birds and flowering plants, a cooling and drying climate, and the current configu ...

, three from the

Mesozoic The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretace ...

, and at least seven from the

Paleozoic The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and ...

Paleozoic

The 410-million-year-old ''Eophalangium sheari'' is known from two specimens, one a female, the other a male. The female bears an

ovipositor The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typical ...

and is about long, whilst the male had a discernable penis. Whether both specimens belong to the same species is not definitely known. They have long legs,

, and no median eyes. Together with the 305-million-year-old ''Hastocularis argus'', it forms the suborder Tetrophthalmi. ''Brigantibunum listoni'' from East Kirkton near

Edinburgh Edinburgh ( ; gd, Dùn Èideann ) is the capital city of Scotland and one of its 32 Council areas of Scotland, council areas. Historically part of the county of Midlothian (interchangeably Edinburghshire before 1921), it is located in Lothian ...

in Scotland is almost 340 million years old. Its placement is rather uncertain, apart from it being a harvestman. From about 300 Mya, several finds are from the

Coal Measures In lithostratigraphy, the coal measures are the coal-bearing part of the Upper Carboniferous System. In the United Kingdom, the Coal Measures Group consists of the Upper Coal Measures Formation, the Middle Coal Measures Formation and the Lower Coa ...

of North America and Europe. While the two described ''Nemastomoides'' species are currently grouped as Dyspnoi, they look more like Eupnoi. ''Kustarachne tenuipes'' was shown in 2004 to be a harvestman, after residing for almost one hundred years in its own arachnid order, the "Kustarachnida". Some fossils from the

Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleo ...

are possibly harvestmen, but these are not well preserved.

Described species

* '' Eophalangium sheari'' Dunlop, 2004 (Tetrophthalmi) — Early Devonian ( Rhynie,

Scotland Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to ...

) * '' Brigantibunum listoni'' Dunlop, 2005 (Eupnoi?) —

Early Carboniferous Early may refer to: History * The beginning or oldest part of a defined historical period, as opposed to middle or late periods, e.g.: ** Early Christianity ** Early modern Europe Places in the United States * Early, Iowa * Early, Texas * Ear ...

(

East Kirkton East or Orient is one of the four cardinal directions or points of the compass. It is the opposite direction from west and is the direction from which the Sun rises on the Earth. Etymology As in other languages, the word is formed from the fa ...

, Scotland) * '' Echinopustulus samuelnelsoni'' Dunlop, 2004 (Dyspnoi?) — Upper Carboniferous (Western

Missouri Missouri is a state in the Midwestern region of the United States. Ranking 21st in land area, it is bordered by eight states (tied for the most with Tennessee): Iowa to the north, Illinois, Kentucky and Tennessee to the east, Arkansas t ...

, U.S.) * '' Eotrogulus fayoli'' Thevenin, 1901 (Dyspnoi: † Eotrogulidae) — Upper Carboniferous (

Commentry Commentry (; Auvergnat: ''Comentriac'') is a commune in the department of Allier in central France. It lies southwest of Moulins in the valley of the Œil. It is within 8 km of one of the geographic centres of France. The film actress ...

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

) * '' Hastocularis argus'' Garwood, 2014 (Tetrophthalmi) — Upper Carboniferous (

Montceau-les-Mines Montceau-les-Mines () is a commune in the Saône-et-Loire department in the region of Bourgogne-Franche-Comté in eastern France. It is the second-largest commune of the metropolitan Communauté urbaine Creusot Montceau, which lies southwest o ...

, France) * '' Kustarachne tenuipes'' Scudder, 1890 (Eupnoi?) — Upper Carboniferous (

Mazon Creek The Mazon Creek fossil beds are a conservation ' found near Morris, in Grundy County, Illinois. The fossils are preserved in ironstone concretions, formed approximately in the mid- Pennsylvanian epoch of the Carboniferous period. These concretio ...

, U.S.) * '' Nemastomoides elaveris'' Thevenin, 1901 (Dyspnoi: † Nemastomoididae) — Upper Carboniferous (Commentary, France) * '' Nemastomoides longipes'' Petrunkevitch, 1913 (Dyspnoi: † Nemastomoididae) — Upper Carboniferous (Mazon Creek, U.S.)

Mesozoic

Currently, no fossil harvestmen are known from the

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest per ...

. So far, they are also absent from the

Lower Cretaceous Lower may refer to: * Lower (surname) * Lower Township, New Jersey *Lower Receiver (firearms) * Lower Wick Gloucestershire, England See also *Nizhny Nizhny (russian: Ни́жний; masculine), Nizhnyaya (; feminine), or Nizhneye (russian: Н� ...

Crato Formation of Brazil, a

Lagerstätte A Lagerstätte (, from '' Lager'' 'storage, lair' '' Stätte'' 'place'; plural ''Lagerstätten'') is a sedimentary deposit that exhibits extraordinary fossils with exceptional preservation—sometimes including preserved soft tissues. These f ...

that has yielded many other terrestrial arachnids. An unnamed long-legged harvestman was reported from the Early Cretaceous of Koonwarra, Victoria, Australia, which may be a Eupnoi. A fossil of '' Halitherses grimaldii'', a long-legged Dyspnoi with large eyes, was found in Burmese amber dating from approximately 100 Mya. It has been suggested that this may be related to the Ortholasmatinae (Nemastomatidae).

Cenozoic

Unless otherwise noted, all species are from the

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', ...

. * '' Trogulus longipes'' Haupt, 1956 (Dyspnoi: Trogulidae) — Geiseltal,

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwee ...

* '' Philacarus hispaniolensis'' (Laniatores: Samoidae?) — Dominican amber * '' Kimula'' species (Laniatores: Kimulidae) — Dominican amber * '' Hummelinckiolus silhavyi'' Cokendolpher & Poinar, 1998 (Laniatores: Samoidae) — Dominican amber * ''

Caddo The Caddo people comprise the Caddo Nation of Oklahoma, a federally recognized tribe headquartered in Binger, Oklahoma. They speak the Caddo language. The Caddo Confederacy was a network of Indigenous peoples of the Southeastern Woodlands, w ...

dentipalpis'' (Eupnoi:

) —

Baltic amber The Baltic region is home to the largest known deposit of amber, called Baltic amber or succinite. It was produced sometime during the Eocene epoch, but exactly when is controversial. It has been estimated that these forests created more than ...

* '' Dicranopalpus ramiger'' (Koch & Berendt, 1854) (Eupnoi: Phalangiidae) — Baltic amber * '' Opilio ovalis'' (Eupnoi: Phalangiidae?) — Baltic amber * '' Cheiromachus coriaceus'' Menge, 1854 (Eupnoi: Phalangiidae?) — Baltic amber * '' Leiobunum longipes'' (Eupnoi: Sclerosomatidae) — Baltic amber * '' Histricostoma tuberculatum'' (Dyspnoi: Nemastomatidae) — Baltic amber * '' Mitostoma denticulatum'' (Dyspnoi: Nemastomatidae) — Baltic amber * '' Nemastoma incertum'' (Dyspnoi: Nemastomatidae) — Baltic amber * '' Sabacon claviger'' (Dyspnoi: Sabaconidae) — Baltic amber * '' Petrunkevitchiana oculata'' (Petrunkevitch, 1922) (Eupnoi: Phalangioidea) — Florissant Fossil Beds National Monument, USA (

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but t ...

) * '' Proholoscotolemon nemastomoides'' (Laniatores:

) — Baltic amber * '' Siro platypedibus'' (Cyphophthalmi:

) — Bitterfeld amber * '' Amauropilio atavus'' (Cockerell, 1907) (Eupnoi: Sclerosomatidae) — Florissant, USA (Oligocene) * '' Amauropilio lacoei'' (''A. lawei''?) (Petrunkevitch, 1922) — Florissant, USA (Oligocene) * '' Pellobunus proavus'' Cokendolpher, 1987 (Laniatores: Samoidae) — Dominican amber * '' Phalangium'' species (Eupnoi: Phalangiidae) — near

Rome , established_title = Founded , established_date = 753 BC , founder = King Romulus ( legendary) , image_map = Map of comune of Rome (metropolitan city of Capital Rome, region Lazio, Italy).svg , map_caption ...

Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...

(

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million year ...

)

References

External links

Joel Hallan's Biology Catalog
(2005)

��Diagnostic photographs and information on North American harvestmen

��Diagnostic photographs and information on European harvestmen * University of Aberdeen

(fossils) * National Museum pag

��A synoptic taxonomic arrangement of the order Opiliones, down to family-group level, including some photos of the families * {{Authority control Arachnid orders Extant Early Devonian first appearances Taxa named by Carl Jakob Sundevall