Misplaced Pages

#464535

87-459: During 1764-1767 he built an egg -shaped clock, containing a complex automatic mechanism. In 1769 Kulibin gave this clock to Catherine II , who assigned Kulibin to be in charge of the mechanical workshop in the Academy of Sciences of Saint Petersburg (established in 1724). There, Kulibin built a “planetary” pocket-clock, which showed not only the current time, but also the month, day of the week,

174-510: A clade within the pulmonate Arachnida (those with book lungs). Arachnida is placed within the Chelicerata , a subphylum of Arthropoda that contains sea spiders and horseshoe crabs , alongside terrestrial animals without book lungs such as ticks and harvestmen . The extinct Eurypterida , sometimes called sea scorpions, though they were not all marine, are not scorpions; their grasping pincers were chelicerae , not homologous with

261-451: A cross grate. In 1776 a model 1/10 the natural size of this bridge was tested by a special commission of academics. Kulibin's project was praised by Leonhard Euler and Daniel Bernoulli , but was never realized. After 1780 Kulibin worked on possibilities for a metallic bridge, but these projects were also rejected by the government. Altogether Kulibin designed three projects for wooden and three projects for metallic bridges. In 1779 he built

348-467: A defensive posture. Some species stridulate to warn off predators by rubbing certain hairs, the stinger or the claws. Certain species have a preference for using either the claws or stinger as defense, depending on the size of the appendages. A few scorpions, such as Parabuthus , Centruroides margaritatus , and Hadrurus arizonensis , squirt venom in a narrow jet as far as 1 meter (3.3 ft) to warn off potential predators, possibly injuring them in

435-429: A gram (around 0.02 oz). Some eggs laid by reptiles and most fish, amphibians, insects, and other invertebrates can be even smaller. Reproductive structures similar to the egg in other kingdoms are termed " spores ", or in spermatophytes " seeds ", or in gametophytes "egg cells". Several major groups of animals typically have readily distinguishable eggs. The most common reproductive strategy for fish

522-542: A green or blue ground colour, while protoporphyrin IX produces reds and browns as a ground colour or as spotting. Non-passerines typically have white eggs, except in some ground-nesting groups such as the Charadriiformes , sandgrouse and nightjars , where camouflage is necessary, and some parasitic cuckoos which have to match the passerine host's egg. Most passerines, in contrast, lay coloured eggs, even if there

609-417: A ladder-like configuration; they contain cysts which produce spermatozoa . Both tubes end in a spermiduct , one on each side of the mesosoma. They connect to glandular symmetrical structures called paraxial organs, which end at the genital orifice. These secrete chitin -based structures which come together to form the spermatophore . The "tail" or metasoma consists of five segments and the telson , which

696-407: A lantern that could emit a powerful light using a weak light source. This invention was used industrially for lighting workshops, lighthouses, ships, etc. In 1791 Kulibin constructed a push-cycle cart, in which he used a flywheel , a brake , a gearbox and roller bearing. The cart was operated by a man pressing pedals. In the same year, he also designed "mechanical legs", a prosthetic device, which

783-436: A longer fetal development. Comparatively anatomically simple animals will be able to go through the full development and leave the egg in a form reminiscent of the adult animal. This is the situation found in hagfish and some snails . Animals with smaller size eggs or more advanced anatomy will still have a distinct larval stage, though the larva will be basically similar to the adult animal, as in lampreys , coelacanth and

870-403: A naked egg cell. Mesolecithal eggs have comparatively more yolk than the microlecithal eggs. The yolk is concentrated in one part of the egg (the vegetal pole ), with the cell nucleus and most of the cytoplasm in the other (the animal pole ). The cell cleavage is uneven, and mainly concentrated in the cytoplasma-rich animal pole. The larger yolk content of the mesolecithal eggs allows for

957-451: A narrow, segmented tail, often carried in a characteristic forward curve over the back and always ending with a stinger . The evolutionary history of scorpions goes back 435 million years . They mainly live in deserts but have adapted to a wide range of environmental conditions, and can be found on all continents except Antarctica . There are over 2,500 described species , with 22 extant (living) families recognized to date. Their taxonomy

SECTION 10

#1732779765465

1044-529: A sclerotized plate called the tergite . Ventrally , somites 3 to 7 are armored with matching plates called sternites . The ventral side of somite 1 has a pair of genital opercula covering the gonopore . Sternite 2 forms the basal plate bearing the pectines , which function as sensory organs. The next four somites, 3 to 6, all bear pairs of spiracles . They serve as openings for the scorpion's respiratory organs, known as book lungs . The spiracle openings may be slits, circular, elliptical or oval according to

1131-492: A scorpion can tolerate high osmotic pressure in its blood. Desert scorpions get most of their moisture from the food they eat but some can absorb water from the humid soil. Species that live in denser vegetation and in more moderate temperatures will drink water on plants and in puddles. A scorpion uses its stinger both for killing prey and defense. Some species make direct, quick strikes with their tails while others make slower, more circular strikes which can more easily return

1218-413: A scorpion is in the back of the cephalothorax, just above the esophagus . As in other arachnids, the nervous system is highly concentrated in the cephalothorax, but has a long ventral nerve cord with segmented ganglia which may be a primitive trait. The pedipalp is a segmented, clawed appendage used for prey immobilization, defense and sensory purposes. The segments of the pedipalp (from closest to

1305-523: A shell and would dry out in the air. Even air-breathing amphibians lay their eggs in water, or in protective foam as with the Coast foam-nest treefrog, Chiromantis xerampelina . Bird eggs are laid by females and incubated for a time that varies according to the species; a single young hatches from each egg. Average clutch sizes range from one (as in condors ) to about 17 (the grey partridge ). Some birds lay eggs even when not fertilized (e.g. hens ); it

1392-429: A shelter underneath stones a few centimeters long. Some may use burrows made by other animals including spiders, reptiles and small mammals. Other species dig their own burrows which vary in complexity and depth. Hadrurus species dig burrows as over 2 m (6 ft 7 in) deep. Digging is done using the mouth parts, claws and legs. In several species, particularly of the family Buthidae, individuals may gather in

1479-491: A variety of prey though some may be highly specialized; Isometroides vescus specializes on burrowing spiders. Prey size depends on the size of the species. Several scorpion species are sit-and-wait predators , which involves them waiting for prey at or near the entrance to their burrow. Others actively seek them out. Scorpions detect their prey with mechanoreceptive and chemoreceptive hairs on their bodies and capture them with their claws. Small animals are merely killed with

1566-616: A very low metabolic rate , and a relatively inactive lifestyle. This enables some to survive six to twelve months of starvation. Most scorpions reproduce sexually, with male and female individuals; species in some genera, such as Hottentotta and Tityus , and the species Centruroides gracilis , Liocheles australasiae , and Ananteris coineaui have been reported, not necessarily reliably, to reproduce through parthenogenesis , in which unfertilized eggs develop into living embryos . Receptive females produce pheromones which are picked up by wandering males using their pectines to comb

1653-460: A warm and favorable temperature range while the embryo grows. When the embryo is adequately developed it hatches, i.e., breaks out of the egg's shell. Some embryos have a temporary egg tooth they use to crack, pip, or break the eggshell or covering. The largest recorded egg is from a whale shark and was 30 cm × 14 cm × 9 cm (11.8 in × 5.5 in × 3.5 in) in size. Whale shark eggs typically hatch within

1740-399: Is based on Soleglad and Fet (2003), which replaced Stockwell's older, unpublished classification. Further taxonomic changes are from papers by Soleglad et al. (2005). The extant taxa to the rank of family (numbers of species in parentheses ) are: Scorpions are found on all continents except Antarctica . The diversity of scorpions is greatest in subtropical areas; it decreases toward

1827-473: Is being revised to account for 21st-century genomic studies. Scorpions primarily prey on insects and other invertebrates , but some species hunt vertebrates . They use their pincers to restrain and kill prey, or to prevent their own predation. The venomous sting is used for offense and defense. During courtship, the male and female grasp each other's pincers and dance while he tries to move her onto his sperm packet . All known species give live birth and

SECTION 20

#1732779765465

1914-866: Is into the clades Buthida and Iurida. The Bothriuridae diverged starting before temperate Gondwana broke up into separate land masses, completed by the Jurassic . The Iuroidea and Chactoidea are both seen not to be single clades, and are shown as " paraphyletic " (with quotation marks) in this 2018 cladogram. Chaeriloidea [REDACTED] Pseudochactoidea [REDACTED] Buthoidea [REDACTED] " Iuroidea " (part) Bothriuroidea [REDACTED] " Chactoidea " (part) " Iuroidea " (part) " Chactoidea " (part) Scorpionoidea [REDACTED] Carl Linnaeus described six species of scorpion in his genus Scorpio in 1758 and 1767; three of these are now considered valid and are called Scorpio maurus , Androctonus australis , and Euscorpius carpathicus ;

2001-414: Is known as oviparity , in which the female lays undeveloped eggs that are externally fertilized by a male. Typically large numbers of eggs are laid at one time (an adult female cod can produce 4–6 million eggs in one spawning) and the eggs are then left to develop without parental care. When the larvae hatch from the egg, they often carry the remains of the yolk in a yolk sac which continues to nourish

2088-425: Is likely to have arisen due to evolution via natural selection. In contrast, many hole-nesting birds have nearly spherical eggs. Many animals feed on eggs. For example, principal predators of the black oystercatcher 's eggs include raccoons , skunks , mink , river and sea otters , gulls , crows and foxes . The stoat ( Mustela erminea ) and long-tailed weasel ( M. frenata ) steal ducks' eggs. Snakes of

2175-416: Is no need of cryptic colors. However, some have suggested that the protoporphyrin markings on passerine eggs actually act to reduce brittleness by acting as a solid-state lubricant. If there is insufficient calcium available in the local soil, the egg shell may be thin, especially in a circle around the broad end. Protoporphyrin speckling compensates for this, and increases inversely to the amount of calcium in

2262-421: Is not strictly a segment. The five segments are merely body rings; they lack apparent sterna or terga, and become larger distally. These segments have keels, setae and bristles which may be used for taxonomic classification. The anus is at the distal and ventral end of the last segment, and is encircled by four anal papillae and the anal arch. The tails of some species contain light receptors. The telson includes

2349-446: Is not uncommon for pet owners to find their lone bird nesting on a clutch of unfertilized eggs, which are sometimes called wind-eggs. The default colour of vertebrate eggs is the white of the calcium carbonate from which the shells are made, but some birds, mainly passerines , produce coloured eggs. The colour comes from pigments deposited on top of the calcium carbonate base; biliverdin and its zinc chelate , and bilirubin , give

2436-485: Is subdivided into a broad anterior portion, the mesosoma or pre-abdomen, and a narrow tail-like posterior, the metasoma or post-abdomen. External differences between the sexes are not obvious in most species. In some, the metasoma is more elongated in males than females. The cephalothorax comprises the carapace , eyes, chelicerae (mouth parts), pedipalps (which have chelae , commonly called claws or pincers) and four pairs of walking legs . Scorpions have two eyes on

2523-423: Is then sucked into the gut in liquid form. Any solid indigestible matter (such as exoskeleton fragments) is trapped by setae in the pre-oral cavity and ejected. The sucked-in food is pumped into the midgut by the pharynx , where it is further digested. The waste passes through the hindgut and out of the anus. Scorpions can consume large amounts of food during one meal. They have an efficient food storage organ and

2610-408: Is thought to act as a shock absorber, protecting the calcite shell from fracture during incubation, such as colliding with other eggs in the nest. Most bird eggs have an oval shape , with one end rounded and the other more pointed. This shape results from the egg being forced through the oviduct . Muscles contract the oviduct behind the egg, pushing it forward. The egg's wall is still shapeable, and

2697-399: Is usually motile whereas the female gamete cell, the ovum , is generally larger and sessile . The male and female gametes combine to produce the zygote cell. In multicellular organisms, the zygote subsequently divides in an organised manner into smaller more specialised cells, so that this new individual develops into an embryo . In most animals, the embryo is the sessile initial stage of

Ivan Kulibin - Misplaced Pages Continue

2784-584: The Carboniferous Period and in amber . Whether the early scorpions were marine or terrestrial has been debated, and while they had book lungs like modern terrestrial species, the most basal such as Eramoscorpius were likely still aquatic. Over 100 fossil species of scorpion have been described. The oldest found as of 2021 is Dolichophonus loudonensis , which lived during the Silurian, in present-day Scotland. Gondwanascorpio from

2871-415: The coelacanths can reach a size of 9 cm (3.5 in) in diameter, and the young go through full development while in the uterus , living on the copious yolk. Animals are commonly classified by their manner of reproduction, at the most general level distinguishing egg-laying (Latin. oviparous ) from live-bearing (Latin. viviparous ). These classifications are divided into more detail according to

2958-414: The grasshopper mouse and desert long-eared bat , which are also immune to their venom. In one study, 70% of the latter's droppings contained scorpion fragments. Scorpions host parasites including mites , scuttle flies , nematodes and some bacteria. The immune system of scorpions gives them resistance to infection by many types of bacteria. When threatened, a scorpion raises its claws and tail in

3045-463: The littoral zone of rivers in Romania, occupy specialized niches. Scorpions range in size from the 8.5 mm (0.33 in) Typhlochactas mitchelli of Typhlochactidae, to the 23 cm (9.1 in) Heterometrus swammerdami of Scorpionidae. The body of a scorpion is divided into two parts or tagmata : the cephalothorax or prosoma , and the abdomen or opisthosoma . The opisthosoma

3132-594: The planula , and either develops directly into the adult animals or forms new adult individuals through a process of budding . Microlecithal eggs require minimal yolk mass. Such eggs are found in flatworms , roundworms , annelids , bivalves , echinoderms , the lancelet and in most marine arthropods . In anatomically simple animals, such as cnidarians and flatworms, the fetal development can be quite short, and even microlecithal eggs can undergo direct development. These small eggs can be produced in large numbers. In animals with high egg mortality, microlecithal eggs are

3219-411: The salamanders . Eggs with a large yolk are called macrolecithal. The eggs are usually few in number, and the embryos have enough food to go through full fetal development in most groups. Macrolecithal eggs are only found in selected representatives of two groups: Cephalopods and vertebrates . Macrolecithal eggs go through a different type of development than other eggs. Due to the large size of

3306-535: The tundra , high-altitude taiga , and mountain tops. The highest altitude reached by a scorpion is 5,500 meters (18,000 ft) in the Andes, for Orobothriurus crassimanus . As regards microhabitats , scorpions may be ground-dwelling, tree-loving , rock-loving or sand-loving . Some species, such as Vaejovis janssi , are versatile and are found in all habitats on Socorro Island , Baja California , while others such as Euscorpius carpathicus , endemic to

3393-447: The vesicle , which contains a symmetrical pair of venom glands . Externally it bears the curved stinger, the hypodermic aculeus, equipped with sensory hairs. Each of the venom glands has its own duct to convey its secretion along the aculeus from the bulb of the gland to immediately near of the tip, where each of the paired ducts has its own venom pore. An extrinsic muscle system in the tail moves it forward and propels and penetrates with

3480-525: The Devonian is among the earliest-known terrestrial animals on the Gondwana supercontinent. Some Palaeozoic scorpions possessed compound eyes similar to those of eurypterids. The Triassic fossils Protochactas and Protobuthus belong to the modern clades Chactoidea and Buthoidea respectively, indicating that the crown group of modern scorpions had emerged by this time. The Scorpiones are

3567-417: The aculeus, while an intrinsic muscle system attached to the glands pumps venom through the stinger into the intended victim. The stinger contains metalloproteins with zinc, hardening the tip. The optimal stinging angle is around 30 degrees relative to the tip. Most scorpion species are nocturnal or crepuscular , finding shelter during the day in burrows, cracks in rocks and tree bark. Many species dig

Ivan Kulibin - Misplaced Pages Continue

3654-413: The adult body, and by the yolk which the egg provides to nourish the embryo. Vertebrate eggs can be classified by the relative amount of yolk . Simple eggs with little yolk are called microlecithal , medium-sized eggs with some yolk are called mesolecithal , and large eggs with a large concentrated yolk are called macrolecithal . This classification of eggs is based on the eggs of chordates , though

3741-540: The air. Often the sex of the developing embryo is determined by the temperature of the surroundings, with cooler temperatures favouring males. Not all reptiles lay eggs; some are viviparous ("live birth"). Dinosaurs laid eggs, some of which have been preserved as petrified fossils. Among mammals, early extinct species laid eggs, as do platypuses and echidnas (spiny anteaters). Platypuses and two genera of echidna are Australian monotremes . Marsupial and placental mammals do not lay eggs, but their unborn young do have

3828-407: The basic principle extends to the whole animal kingdom . Small eggs with little yolk are called microlecithal. The yolk is evenly distributed, so the cleavage of the egg cell cuts through and divides the egg into cells of fairly similar sizes. In sponges and cnidarians , the dividing eggs develop directly into a simple larva, rather like a morula with cilia . In cnidarians, this stage is called

3915-492: The biological sense. In placental mammals , the egg itself is void of yolk, but develops an umbilical cord from structures that in reptiles would form the yolk sac. Receiving nutrients from the mother, the fetus completes the development while inside the uterus. Eggs are common among invertebrates , including insects , spiders , mollusks , and crustaceans . All sexually reproducing life, including both plants and animals, produces gametes . The male gamete cell, sperm ,

4002-596: The body outward) are coxa, trochanter, femur, patella, tibia (including the fixed claw and the manus) and tarsus (moveable claw). A scorpion has darkened or granular raised linear ridges, called "keels" or "carinae" on the pedipalp segments and on other parts of the body; these are useful as taxonomic characters . Unlike those of some other arachnids, the legs have not been modified for other purposes, though they may occasionally be used for digging, and females may use them to catch emerging young. The legs are covered in proprioceptors , bristles and sensory setae . Depending on

4089-404: The cells of incipient multicellular organisms. The cycle of the egg's formation is started by the gamete ovum being released ( ovulated ) and egg formation being started. The finished egg is then ovipositioned and eventual egg incubation can start. Scientists often classify animal reproduction according to the degree of development that occurs before the new individuals are expelled from

4176-458: The chamber to refill. The 7th and last somite does not bear appendages or any other significant external structures. The mesosoma contains the heart or "dorsal vessel" which is the center of the scorpion's open circulatory system . The heart is continuous with a deep arterial system which spreads throughout the body. Sinuses return deoxygenated blood ( hemolymph ) to the heart; the blood is re-oxygenated by cardiac pores. The mesosoma also contains

4263-401: The claws, particularly by large-clawed species. Larger and more aggressive prey is given a sting. Scorpions, like other arachnids, digest their food externally. The chelicerae, which are very sharp, are used to pull small amounts of food off the prey item into a pre-oral cavity below the chelicerae and carapace. The digestive juices from the gut are egested onto the food, and the digested food

4350-401: The complex tissues that identify amniotes. The eggs of the egg-laying mammals (the platypus and the echidnas ) are macrolecithal eggs very much like those of reptiles . The eggs of marsupials are likewise macrolecithal, but rather small, and develop inside the body of the female, but do not form a placenta . The young are born at a very early stage, and can be classified as a " larva " in

4437-476: The crowded cliff ledges on which they breed. Yolks of birds' eggs are yellow from carotenoids , it is affected by their living conditions and diet. Bird eggshells are diverse. For example: Tiny pores in bird eggshells allow the embryo to breathe. The domestic hen 's egg has around 7000 pores. Some bird eggshells have a coating of vaterite spherules , which is a rare polymorph of calcium carbonate. In Greater Ani Crotophaga major this vaterite coating

SECTION 50

#1732779765465

4524-461: The development that occurs before the offspring are expelled from the adult's body. Traditionally: The term hemotrophic derives from the Latin for blood-feeding, contrasted with histotrophic for tissue-feeding. Scorpion see Taxonomy Scorpions are predatory arachnids of the order Scorpiones . They have eight legs and are easily recognized by a pair of grasping pincers and

4611-460: The egg until the embryo has become an animal fetus that can survive on its own, at which point the animal hatches. Most arthropods , vertebrates (excluding live-bearing mammals ), and mollusks lay eggs, although some, such as scorpions , do not. Reptile eggs, bird eggs , and monotreme eggs are laid out of water and are surrounded by a protective shell , either flexible or inflexible. Eggs laid on land or in nests are usually kept within

4698-431: The extreme changes in temperature from day to night or between seasons; Pectinibuthus birulai lives in a temperature range of −30–50 °C (−22–122 °F). Scorpions that live outside deserts prefer lower temperatures. The ability to resist cold may be related to the increase in the sugar trehalose when the temperature drops. Some species hibernate . Scorpions appear to have resistance to ionizing radiation . This

4785-600: The eyes. Some Ananteris species can shed parts of their tail to escape predators. The parts do not grow back, leaving them unable to sting and defecate, but they can still catch small prey and reproduce for at least eight months afterward. Scorpions generally prey on insects, particularly grasshoppers , crickets , termites , beetles and wasps . Other prey include spiders, solifugids , woodlice and even small vertebrates including lizards, snakes and mammals. Species with large claws may prey on earthworms and mollusks. The majority of species are opportunistic and consume

4872-427: The female cares for the young as their exoskeletons harden, transporting them on her back. The exoskeleton contains fluorescent chemicals and glows under ultraviolet light. The vast majority of species do not seriously threaten humans, and healthy adults usually do not need medical treatment after a sting. About 25 species (fewer than one percent ) have venom capable of killing a human, which happens frequently in

4959-650: The genera Dasypeltis and Elachistodon specialize in eating eggs. Brood parasitism occurs in birds when one species lays its eggs in the nest of another. In some cases, the host's eggs are removed or eaten by the female, or expelled by her chick. Brood parasites include the cowbirds and many Old World cuckoos . Like amphibians, amniotes are air-breathing vertebrates , but they have complex eggs or embryos , including an amniotic membrane . Amniotes include reptiles (including dinosaurs and their descendants, birds) and mammals. Reptile eggs are often rubbery and are always initially white. They are able to survive in

5046-494: The individual life cycle, and is followed by the emergence (that is, the hatching) of a motile stage. The zygote or the ovum itself or the sessile organic vessel containing the developing embryo may be called the egg. A recent proposal suggests that the phylotypic animal body plans originated in cell aggregates before the existence of an egg stage of development . Eggs, in this view, were later evolutionary innovations , selected for their role in ensuring genetic uniformity among

5133-411: The larvae for a few days as they learn how to swim. Once the yolk is consumed, there is a critical point after which they must learn how to hunt and feed or they will die. A few fish, notably the rays and most sharks use ovoviviparity in which the eggs are fertilized and develop internally. However, the larvae still grow inside the egg consuming the egg's yolk and without any direct nourishment from

5220-784: The late 19th century in Sheerness in England at 51°N, while Paruroctonus boreus lives as far north as Red Deer, Alberta , at 52°N. A few species are on the IUCN Red List ; Lychas braueri is classed as critically endangered (2014), Isometrus deharvengi as endangered (2016) and Chiromachus ochropus as vulnerable (2014). Scorpions are xerocoles , meaning they primarily live in deserts , but they can be found in virtually every terrestrial habitat including high-elevation mountains, caves, and intertidal zones . They are largely absent from boreal ecosystems such as

5307-418: The mother also providing direct nourishment. The eggs of fish and amphibians are jellylike. Cartilaginous fish (sharks, skates, rays, chimaeras) eggs are fertilized internally and exhibit a wide variety of both internal and external embryonic development. Most fish species spawn eggs that are fertilized externally, typically with the male inseminating the eggs after the female lays them. These eggs do not have

SECTION 60

#1732779765465

5394-409: The mother. At 1.5 kg (3.3 lb) and up to 17.8 cm × 14 cm (7.0 in × 5.5 in), the ostrich egg is the largest egg of any living bird, though the extinct elephant bird and some non-avian dinosaurs laid larger eggs. The bee hummingbird produces the smallest known bird egg, which measures between 6.35–11.4 millimetres (0.250–0.449 in) long and weighs half of

5481-432: The mother. The mother then gives birth to relatively mature young. In certain instances, the physically most developed offspring will devour its smaller siblings for further nutrition while still within the mother's body. This is known as intrauterine cannibalism . In certain scenarios, some fish such as the hammerhead shark and reef shark are viviparous , with the egg being fertilized and developed internally, but with

5568-421: The norm, as in bivalves and marine arthropods. However, the latter are more complex anatomically than e.g. flatworms, and the small microlecithal eggs do not allow full development. Instead, the eggs hatch into larvae , which may be markedly different from the adult animal. In placental mammals, where the embryo is nourished by the mother throughout the whole fetal period, the egg is reduced in size to essentially

5655-483: The order Scorpiones in 1837. He divided it into four families, the six-eyed scorpions "Scorpionides", the eight-eyed scorpions "Buthides", the ten-eyed scorpions "Centrurides", and the twelve-eyed scorpions "Androctonides". More recently, some twenty-two families containing over 2,500 species of scorpions have been described, with many additions and much reorganization of taxa in the 21st century. There are over 100 described taxa of fossil scorpions. This classification

5742-504: The other three are dubious names. He placed the scorpions among his "Insecta aptera" (wingless insects), a group that included Crustacea, Arachnida and Myriapoda . In 1801, Jean-Baptiste Lamarck divided up the "Insecta aptera", creating the taxon Arachnides for spiders, scorpions, and acari (mites and ticks), though it also contained the Thysanura , Myriapoda and parasites such as lice. German arachnologist Carl Ludwig Koch created

5829-468: The parts of the world where they live, primarily where access to medical treatment is unlikely. Scorpions appear in art, folklore, mythology, and commercial brands. Scorpion motifs are woven into kilim carpets for protection from their sting. Scorpius is the name of a constellation; the corresponding astrological sign is Scorpio . A classical myth about Scorpius tells how the giant scorpion and its enemy Orion became constellations on opposite sides of

5916-621: The pincers (second appendages) of scorpions. Scorpiones is sister to the Tetrapulmonata , a terrestrial group of pulmonates containing the spiders and whip scorpions. This 2019 cladogram summarizes: Pycnogonida (sea spiders) [REDACTED] Xiphosura (horseshoe crabs) [REDACTED] † Eurypterida (sea scorpions) [REDACTED] ( ticks , harvestmen , etc) [REDACTED] [REDACTED] Araneae (spiders) [REDACTED] Pedipalpi ( whip scorpions , etc) [REDACTED] Recent studies place pseudoscorpions as

6003-413: The pointed end develops at the back. . One hypothesis is that long, pointy eggs are an incidental consequence of having a streamlined body typical of birds with strong flying abilities; flight narrows the oviduct, which changes the type of egg a bird can lay. Cliff-nesting birds often have highly conical eggs. They are less likely to roll off, tending instead to roll around in a tight circle; this trait

6090-546: The poles and equator, though scorpions are found in the tropics. Scorpions did not occur naturally in Great Britain but were accidentally introduced by humans, and have now established a population. New Zealand , and some of the islands in Oceania , have in the past had small populations of introduced scorpions, but they were exterminated. Five colonies of Euscorpius flavicaudis have established themselves since

6177-402: The reproductive system. The female gonads are made of three or four tubes that run parallel to each other and are connected by two to four transverse anastomoses . These tubes are the sites for both oocyte formation and embryonic development. They connect to two oviducts which connect to a single atrium leading to the genital orifice. Males have two gonads made of two cylindrical tubes with

6264-550: The same shelter; bark scorpions may aggregate up to 30 individuals. In some species, families of females and young sometimes aggregate. Scorpions prefer areas where the temperature remains in the range of 11–40 °C (52–104 °F), but may survive temperatures from well below freezing to desert heat. Scorpions can withstand intense heat: Leiurus quinquestriatus , Scorpio maurus and Hadrurus arizonensis can live in temperatures of 45–50 °C (113–122 °F) if they are sufficiently hydrated. Desert species must deal with

6351-493: The season and the current moon phase. Kulibin also designed projects for tower clocks, miniature "clock-in-a-ring" types and others. He also worked on new ways to facet glass for use in microscopes , telescopes and other optical instruments. During the 1770s, he designed a wooden one-arch bridge over the Neva river with a span of 298 metres (instead of the typically used 50–60 metre spans), offering to use an original girder with

6438-478: The sister group of scorpions in the clade Panscorpiones, which together with Tetrapulmonata makes up the clade Arachnopulmonata. The internal phylogeny of the scorpions has been debated, but genomic analysis consistently places the Bothriuridae as sister to a clade consisting of Scorpionoidea and Chactoidea . The scorpions diversified between the Devonian and the early Carboniferous . The main division

6525-665: The sky. The word scorpion originated in Middle English between 1175 and 1225 AD from Old French scorpion , or from Italian scorpione , both derived from the Latin scorpio , equivalent to scorpius , which is the romanization of the Greek σκορπίος  – skorpíos , with no native IE etymology (cfr. Arabic ʕaqrab 'scorpion', Proto-Germanic *krabbô 'crab'). Scorpion fossils have been found in many strata , including marine Silurian and estuarine Devonian deposits, coal deposits from

6612-568: The small size of the eggs does not allow for direct development, and the eggs hatch to a larval stage ("fry"). In terrestrial animals with macrolecithal eggs, the large volume to surface ratio necessitates structures to aid in transport of oxygen and carbon dioxide, and for storage of waste products so that the embryo does not suffocate or get poisoned from its own waste while inside the egg, see amniote . In addition to bony fish and cephalopods, macrolecithal eggs are found in cartilaginous fish , reptiles , birds and monotreme mammals. The eggs of

6699-416: The soil. For the same reason, later eggs in a clutch are more spotted than early ones as the female's store of calcium is depleted. The color of individual eggs is also genetically influenced, and appears to be inherited through the mother only, suggesting that the gene responsible for pigmentation is on the sex-determining W chromosome (female birds are WZ, males ZZ). It used to be thought that color

6786-408: The species, the legs may have spines and spurs. The mesosoma or preabdomen is the broad part of the opisthosoma. In the early stages of embryonic development the mesosoma consist of eight segments, but the first segment disappear before birth, so the mesosoma in scorpions actually consist of segments 2-8. These anterior seven somites (segments) of the opisthosoma are each covered dorsally by

6873-422: The species. There are thus four pairs of book lungs; each consists of some 140 to 150 thin lamellae filled with air inside a pulmonary chamber, connected on the ventral side to an atrial chamber which opens into a spiracle. Bristles hold the lamellae apart. A muscle opens the spiracle and widens the atrial chamber; dorsoventral muscles contract to compress the pulmonary chamber, forcing air out, and relax to allow

6960-515: The stinger to a position where it can strike again. Leiurus quinquestriatus can whip its tail at a speed of up to 128 cm/s (50 in/s) in a defensive strike. Scorpions may be attacked by other arthropods like ants, spiders, solifugids and centipedes . Major predators include frogs, lizards, snakes, birds, and mammals. Meerkats are somewhat specialized in preying on scorpions, biting off their stingers and being immune to their venom. Other predators adapted for hunting scorpions include

7047-478: The top of the cephalothorax, and usually two to five pairs of eyes along the front corners of the cephalothorax. While unable to form sharp images, their central eyes are amongst the most light sensitive in the animal kingdom, especially in dim light, which makes it possible for nocturnal species to use starlight to navigate at night. The chelicerae are at the front and underneath the carapace. They are pincer-like and have three segments and sharp "teeth". The brain of

7134-432: The yolk, the cell division can not split up the yolk mass. The fetus instead develops as a plate-like structure on top of the yolk mass, and only envelopes it at a later stage. A portion of the yolk mass is still present as an external or semi-external yolk sac at hatching in many groups. This form of fetal development is common in bony fish , even though their eggs can be quite small. Despite their macrolecithal structure,

7221-456: Was applied to the shell immediately before laying, but subsequent research shows that coloration is an integral part of the development of the shell, with the same protein responsible for depositing calcium carbonate, or protoporphyrins when there is a lack of that mineral. In species such as the common guillemot , which nest in large groups, each female's eggs have very different markings, making it easier for females to identify their own eggs on

7308-568: Was discovered in the early 1960s when scorpions were found to be among the few animals to survive nuclear tests at Reggane , Algeria. Desert scorpions have several adaptations for water conservation. They excrete insoluble compounds such as xanthine , guanine , and uric acid , not requiring water for their removal from the body. Guanine is the main component and maximizes the amount of nitrogen excreted. A scorpion's cuticle holds in moisture via lipids and waxes from epidermal glands, and protects against ultraviolet radiation . Even when dehydrated,

7395-467: Was discovered on September 4, 1987 by L. V. Zhuravleva at Nauchnyj . On May 20, 2020, a special economic zone of industrial and production type "Kulibin" was established in Russia (Nizhny Novgorod region), named after Kulibin. Egg (biology) An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote ) and to incubate from it an embryo within

7482-694: Was fired from the academy and returned to Nizhny Novgorod , where he designed a method of sailing upstream and built a ship which he had started to design back in 1782. Tests indicated that such ships were indeed feasible, but they were never used. During the same time, Kulibin had projects on using steam engines to move cargo ships, on creating salt mining machines, different kinds of mills , pianos and other projects. Kulibin died in 1818 after spending his last years in poverty. The International Astronomical Union 's Minor Planet Center has named an asteroid in Kulibin's honor: 5809 Kulibin . The asteroid

7569-511: Was later used by a French entrepreneur. In 1793 Kulibin constructed an elevator that lifted a cabin using screw mechanisms. In 1794 he created an optical telegraph for transmitting signals over distance. He assembled the famous Peacock Clock created by James Cox and purchased by Catherine the Great , the only large 18th century automaton that has come down to us in its authentic configuration without any change or modification. In 1801 Kulibin

#464535