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Harvestmen
The Opiliones (formerly Phalangida) are an order 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 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 the Arachnida is disputed; their closest relatives may be the mites (Acari) or the Novogenuata (the Scorpiones, Pseudoscorpiones, and Solifugae). Althou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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, Scopulophthalmi, and Sternophthalmi. Description Cyphophthalmi are smaller than the more familiar "daddy long-legs" harvestmen, with adults ranging from 1 to 7 mm in length. Moreover, their legs are relatively short compared to most other harvestmen, typically shorter than the body. Some superficially resemble mites, which is where they get their common name. Their coloration is almost always some shade of brown, with a heavily sclerotized body, and they are quite inconspicuous, residing in leaf litter or in caves. Many Cyphophthalmi are eyeless, and presumably rely on olfactory cues to find food and mates. Very little is known about their behavior, though they likely subsist mostly by scavenging and preying on minute arthropods. They ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrophthalmi
Tetrophthalmi is an extinct suborder of Opiliones (commonly known as harvestmen or daddy longlegs) that had both median and lateral eyes. First described in 2014, it is known from two extinct species. Phylogenetic analysis suggests that this eye arrangement is the ancestral condition for harvestmen, placing Tetrophthalmi and Cyphophthalmi in a basal position within Opiliones. Classification history In the early 1980s, a tiny fossil was extracted from the Montceau-les-Mines Lagerstätte deposit in Eastern France. The fossil went unstudied for more than 30 years before paleontologist Russell Garwood used X-ray computed tomography (CT scans) to investigate the fossil. In 2014, a team led by Garwood identified the specimen as a novel species, '' Hastocularis argus'', named for the 100-eyed giant Argus Panoptes in Greek mythology. According to their analysis, the specimen died, and was rapidly buried approximately 305 million years ago. Before it decayed, its body was surround ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arachnid
Arachnida () is a class of joint-legged invertebrate animals (arthropods), in the subphylum Chelicerata. Arachnida includes, among others, spiders, scorpions, ticks, mites, pseudoscorpions, harvestmen, camel spiders, whip spiders and vinegaroons. Almost all adult arachnids have eight legs, although the front pair of legs in some species has converted to a sensory function, while in other species, different appendages can grow large enough to take on the appearance of extra pairs of legs. The term is derived from the Greek word (''aráchnē'', 'spider'), from the myth of the hubristic human weaver Arachne, who was turned into a spider. Almost all extant arachnids are terrestrial, living mainly on land. However, some inhabit freshwater environments and, with the exception of the pelagic zone, marine environments as well. They comprise over 100,000 named species, of which 47,000 are species of spiders. Morphology Almost all adult arachnids have eight legs, unlike adult i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dyspnoi
Dyspnoi is a suborder of harvestmen, currently comprising 43 extant genera and 356 extant species, although more species are expected to be described in the future. The eight families are currently grouped into three superfamilies: the Acropsopilionoidea, Ischyropsalidioidea, and Troguloidea. Distribution The Dyspnoi are one of the most biogeographically conserved higher groups of harvestmen. With the exception of Acropsopilioidea, none occur in the Southern Hemisphere, and most families are restricted along temperate regions. The only exceptions are some Ortholasmatinae (Nemastomatidae) inhabiting the tropics on high mountains in Mexico ('' Ortholasma bolivari'') and northern Thailand ('' Dendrolasma angka''). Systematics * Acropsopilionoidea ** Acropsopilionidae (3 genera, 19 species) * Ischyropsalidoidea **Ischyropsalidoidea ''Incertae sedis'' ***'' Crosbycus dasycnemus'' ***'' Hesperonemastoma'' (5 species) ** Ischyropsalididae *** Ceratolasmatinae (2 genera, 8 species) * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pholcidae
The Pholcidae are a family of araneomorph spiders. The family contains over 1,800 individual species of pholcids, including those commonly known as cellar spider, daddy long-legs spider, carpenter spider, daddy long-legger, vibrating spider, gyrating spider, long daddy, and skull spider. The family, first described by Carl Ludwig Koch in 1850, is divided into 94 genera. The common name "daddy long-legs" is used for several species, especially '' Pholcus phalangioides'', but is also the common name for several other arthropod groups, including harvestmen and crane flies. Appearance Pholcids are thin and delicate arachnids. The body, resembling the shape of a peanut, is approximately 2–10 mm (0.08–0.39 inch) in length, and the legs may be up to 50 mm (1.97 inches) long. ''Pholcus'' and ''Smeringopus'' have cylindrical abdomens and eyes arranged in two lateral groups of three and two smaller median contiguous eyes. Arrangements of eight and si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 chitin, often mineralised with calcium carbonate. The arthropod body plan consists of segments, each with a pair of appendages. Arthropods are bilaterally symmetrical and their body possesses an external skeleton. In order to keep growing, they must go through stages of moulting, a process by which they shed their exoskeleton to reveal a new one. Some species have wings. They are an extremely diverse group, with up to 10 million species. The haemocoel, an arthropod's internal cavity, through which its haemolymph – analogue of blood – circulates, accommodates its interior organs; it has an open circulatory system. Like their exteriors, the internal organs of arthropods are generally built of repeated segments. Their nervous system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eupnoi
The Eupnoi are a suborder of harvestmen, with more than 200 genera, and about 1,700 described species. They consist of two superfamilies, the Phalangioidea with many long-legged species common to northern temperate regions, and the small group Caddoidea, which have prominent eyes and spiny pedipalps. (2007): Morphology and Functional Anatomy. In: Pinto-da-Rocha ''et al.'' 2007: 17f Examples of this suborder include '' Hadrobunus grandis'' (Sclerosomatidae), ''Phalangium opilio'' and '' Dicranopalpus ramosus'' (Phalangiidae). Distribution Caddoidea are mostly found in temperate zones of both hemispheres; however, they are known from the Palearctic only from Japan, and from Baltic amber (about 40 million years old). One species known from Japan is also found in North America, where several more species are found. Other species occur in Southern South America, Venezuela, New Zealand and Australia. Neopilionidae show a Gondwanan distribution, with species found in South America, S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 ''cephalothorax'' and ''abdomen'' in some groups.) The word ''cephalothorax'' is derived from the Greek words for head (, ') and thorax (, '). This fusion of the head and thorax is seen in chelicerates and crustaceans; in other groups, such as the Hexapoda (including insects), the head remains free of the thorax. In horseshoe crabs and many crustaceans, a hard shell called the carapace covers the cephalothorax. Arachnid anatomy Fovea The fovea is the centre of the cephalothorax and is located behind the head (only in spiders).Dalton, Steve (2008). ''Spiders; The Ultimate Predators''. A & C Black, London. P.p. 19. . It is often important in identification. It can be transverse or procurved Smith, A. M. (1990c). Baboon spiders: Tarantulas of Afr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 evidence of a close relationship. Most mites are tiny, less than in length, and have a simple, unsegmented body plan. The small size of most species makes them easily overlooked; some species live in water, many live in soil as decomposers, others live on plants, sometimes creating galls, while others again are predators or parasites. This last type includes the commercially destructive ''Varroa'' parasite of honey bees, as well as scabies mites of humans. Most species are harmless to humans, but a few are associated with allergies or may transmit diseases. The scientific discipline devoted to the study of mites is called acarology. Evolution and taxonomy The mites are not a defined taxon, but is used for two distinct groups of arachnids ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 diversity among all orders of organisms. Spiders are found worldwide on every continent except for Antarctica, and have become established in nearly every land habitat. , 50,356 spider species in 132 families have been recorded by taxonomists. However, there has been debate among scientists about how families should be classified, with over 20 different classifications proposed since 1900. Anatomically, spiders (as with all arachnids) differ from other arthropods in that the usual body segments are fused into two tagmata, the cephalothorax or prosoma, and the opisthosoma, or abdomen, and joined by a small, cylindrical pedicel, however, as there is currently neither paleontological nor embryological evidence that spiders ever had a sep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Araneae
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 diversity among all orders of organisms. Spiders are found worldwide on every continent except for Antarctica, and have become established in nearly every land habitat. , 50,356 spider species in 132 families have been recorded by taxonomists. However, there has been debate among scientists about how families should be classified, with over 20 different classifications proposed since 1900. Anatomically, spiders (as with all arachnids) differ from other arthropods in that the usual body segments are fused into two tagmata, the cephalothorax or prosoma, and the opisthosoma, or abdomen, and joined by a small, cylindrical pedicel, however, as there is currently neither paleontological nor embryological evidence that spiders ever had a separate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Novogenuata
Dromopoda is a subclass of the arachnids, including the Opiliones (harvestmen), Scorpions, Pseudoscorpions 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 n ... ("camel spiders"). The latter three are sometimes grouped as Novogenuata. Combined morphological and molecular analyses have shown Dromopoda to be monophyletic. However, a strictly molecular analysis did not support the monophyly of Dromopoda. References Arachnid taxonomy Arthropod subclasses {{arachnid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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