The evolutionary ancestry of arthropods dates back to the Cambrian period. The group is generally regarded as monophyletic, and many analyses support the placement of arthropods with cycloneuralians (or their constituent clades) in a superphylum Ecdysozoa. Overall, however, the basal relationships of animals are not yet well resolved. Likewise, the relationships between various arthropod groups are still actively debated. Today, arthropods contribute to the human food supply both directly as food, and more importantly, indirectly as pollinators of crops. Some species are known to spread severe disease to humans, livestock, and crops. (Full article...)
Eusarcana is known for its odd proportions and features; the broad abdomen, thin and long tail, spined and forward-facing walking appendages and sharp and curved tail spike differentiate it from most other eurypterids, but are shared with other carcinosomatid eurypterids. The triangular carapace, oddly positioned forward-facing eyes differentiate the genus further from its closest relatives. At 80 centimetres (31.5 in) in length, E. scorpionis represents a moderately large species of eurypterid, and far exceeded other representatives of the genus in size, such as the 4 cm (1.5 in) long E. obesus.
Originally described under the name Eusarcus, this name was preoccupied by a genus of living harvestmen in the family Gonyleptidae. Following the discovery of this homonym, the genus was also wrongly recognized as synonymous with the related Carcinosoma and was only given replacement names for the older name decades after the error was discovered, first as Eusarcana in 1942 and later as Paracarcinosoma (assumed to have been named without knowledge of the earlier replacement name) in 1964. (Full article...)
Terropterus was the earliest known and largest mixopterid eurypterid. Fossil specimens referred to T. xiushanensis are estimated to have reached up to 40 centimeters (15.7 in) in length, but other fossils, either representing older T. xiushanensis or a second species of Terropterus, demonstrate that members of the genus could reach upwards of at least 100 centimeters (3.3 ft) in length. Terropterus is the only mixopterid known from the ancient southern continent of Gondwana, with the other two mixopterid genera, Mixopterus and Lanarkopterus, only being known from what was once the northern continent of Laurussia. The discovery of Terropterus significantly expanded the known geographical and temporal ranges of the Mixopteridae.
The deposits in which fossils of Terropterus were discovered were once a marine environment. Fossils of several other groups are known from the same deposits, including trilobites, brachiopods, gastropods and other eurypterids. Due to its large size and its predatory adaptations, including the characteristic mixopterid large and spiny forward-facing appendages, Terropterus was likely the apex predator of its marine ecosystem. (Full article...)
Hibbertopterus was the largest eurypterid within the stylonurine suborder, with the largest fossil specimens suggesting that H. scouleri could reach lengths around 180–200 centimetres (5.9–6.6 ft). Though this is significantly smaller than the largest eurypterid overall, Jaekelopterus, which could reach lengths of around 250 centimetres (8.2 ft), Hibbertopterus is likely to have been the heaviest due to its broad and compact body. Furthermore, trackway evidence indicates that the South African species H. wittebergensis might have reached lengths similar to Jaekelopterus.
Like many other stylonurine eurypterids, Hibbertopterus fed through a method called sweep-feeding. It used its specialised forward-facing appendages (limbs), equipped with several spines, to rake through the substrate of the environments in which it lived in search for small invertebrates to eat, which it could then push towards its mouth. Though long hypothesised, the fact that eurypterids were capable of terrestrial locomotion was definitely proven through the discovery of a fossil trackway made by Hibbertopterus in Scotland. The trackway showed that an animal measuring around 160 centimetres (5.2 ft) had slowly lumbered across a stretch of land, dragging its telson (the posteriormost division of its body) across the ground after it. How Hibbertopterus could survive on land, however briefly, is unknown but it might have been possible through either its gills being able to function in air as long as they were wet or by the animal possessing a dual respiratory system, theorised to have been present in at least some eurypterids. (Full article...)
Crickets have mainly cylindrically shaped bodies, round heads, and long antennae. Behind the head is a smooth, robust pronotum. The abdomen ends in a pair of long cerci; females have a long, cylindrical ovipositor. Diagnostic features include legs with 3-segmented tarsi; as with many Orthoptera, the hind legs have enlarged femora, providing power for jumping. The front wings are adapted as tough, leathery elytra, and some crickets chirp by rubbing parts of these together. The hind wings are membranous and folded when not in use for flight; many species, however, are flightless. The largest members of the family are the bull crickets, Brachytrupes, which are up to 5 cm (2 in) long.
Crickets are distributed all around the world except at latitudes 55° or higher, with the greatest diversity being in the tropics. They occur in varied habitats from grassland, bushes, and forests to marshes, beaches, and caves. Crickets are mainly nocturnal, and are best known for the loud, persistent, chirping song of males trying to attract females, although some species are mute. The singing species have good hearing, via the tympana on the tibiae of the front legs. (Full article...)
Horseshoe crabs are arthropods of the family Limulidae and are the only surviving xiphosurans. Despite their name, they are not true crabs or crustaceans. Rather, they are chelicerates. This makes them more closely related to arachnids like spiders, ticks, and scorpions. The body of a horseshoe crab is divided into three main parts: the cephalothorax, abdomen, and telson. The largest of these, the cephalothorax, houses most of the animal's eyes, limbs, and internal organs. It is also where the animal gets its name, as its shape somewhat resembles that of a horseshoe. Horseshoe crabs have changed little in appearance since they first evolved in the Triassic, earning them the title of "living fossil".
Only four species of horseshoe crab are alive today. Most are marine, though the mangrove horseshoe crab is often found in brackish water. Additionally, certain extinct species transitioned to living in freshwater. Horseshoe crabs primarily live at the water's bottom but they can swim if needed. In the modern day, their distribution is limited, only found along the east coasts of North America and South Asia.
Horseshoe crabs are often caught for their blood, which contains Limulus amebocyte lysate, a chemical used to detect bacterial endotoxins. Additionally, the animals are used as fishing bait in the United States and eaten as a delicacy in some parts of Asia. In recent years, horseshoe crabs have experienced a population decline. This is mainly due to coastal habitat destruction and overharvesting. To ensure their continuous existence, many areas have enacted regulations on harvesting and established captive breeding programs. (Full article...)
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The bush coconut, or bloodwood apple, is an Australian bush tucker food. It is an insect gall with both plant and animal components: an adult female scale insect and her offspring (of genus Cystococcus) live in a gall induced on a bloodwood eucalypt tree (Corymbia). Bush coconuts can vary from golf ball to tennis ball size. They have a hard and lumpy outer layer. The inner layer is a white flesh that contains the female insect and her offspring. There are three known species of Cystococcus responsible for forming the bush coconut: Cystococcus pomiformis, Cystococcus echiniformis and Cystococcus campanidorsalis. C. pomiformis is the most common species. The bush coconut is found in Western Australia, the Northern Territory, Queensland and New South Wales.
The bush coconut is picked from the host tree and cracked open to allow the flesh and scale insects to be eaten. Both have a high protein content and are used as a food source by humans and other animals. The name 'bush coconut' is derived from the white flesh of the inner layer, which is similar in appearance to that of a coconut, and the taste of the flesh has been said to have a coconut flavour. The bush coconut has been depicted in Indigenous Australian dreaming and used as inspiration in their artwork. (Full article...)
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Female
Zygoballus sexpunctatus is a species of jumping spider which occurs in the southeastern United States where it can be found in a variety of grassy habitats. Adult spiders measure between 3 and 4.5 mm in length. The cephalothorax and abdomen are bronze to black in color, with reddish brown or yellowish legs. The male has distinctive enlarged chelicerae (the mouthparts used for grasping prey) and front femora (the third, and typically largest, leg segments). Like many jumping spiders, Z. sexpunctatus males exhibit ritualized courtship and agonistic behavior. (Full article...)
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Replica of the M. ohioensisholotype, Orton Geology Museum
Megalograptus is a genus of eurypterid, an extinct group of aquatic arthropods. Fossils of Megalograptus have been recovered in deposits of Katian (Late Ordovician) age in North America. The genus contains five species: M. alveolatus, M. ohioensis, M. shideleri, M. welchi and M. williamsae, all based on fossil material found in the United States. Fossils unassigned to any particular species have also been found in Canada. The generic name translates to "great writing" and originates from the mistaken original belief that Megalograptus was a type of graptolite, often given names ending with -graptus (meaning 'writing').
Megalograptus was a large predatory megalograptid eurypterid, with the largest and best known species, M. ohioensis, reaching body lengths of 78 centimeters (2 ft 7 in). Some species were substantially smaller, with the smallest, belonging to a hitherto undetermined species, only growing to about 10 cm (3.9 in) in length. Morphologically, Megalograptus was highly distinct. The two most distinctive features of Megalograptus were its massive and spined forward-facing appendages, far larger than similar structures in other eurypterids, and its telson (the last division of the body). The sharp spike-shaped telson of Megalograptus was not venomous, but it was specialized in that it was surrounded by unique cercal blades, capable of grasping. Certain fossils of three different species, M. ohioensis, M. shideleri and M. williamsae, are so well-preserved that researchers have been able to infer the coloration they might have possessed in life. All three were deduced to have been brown and black in color, with M. ohioensis being darker than the others.
First described by Samuel Almond Miller in 1874, based on fragmentary fossil remains of the species M. welchi, Megalograptus being a graptolite was not formally questioned until 1908, when Rudolf Ruedemann recognized the fossils as eurypterid remains. Megalograptus was noted as being similar to Echinognathus by August Foerste in 1912 and the two genera have been considered closely related since then, and have been grouped together in the Megalograptidae since 1955. In 2015, the genus Pentecopterus was also assigned to the family. Kenneth E. Caster and Erik N. Kjellesvig-Waering revised Megalograptus in 1955, owing to the discovery of more complete fossil material of the new species M. ohioensis. Caster and Kjellesvig-Waering conducted further work on Megalograptus over the following years. In 1964, they named the species M. shideleri and M. williamsae and reclassified the fragmentary eurypterid Ctenopterus alveolatus as a species of Megalograptus. (Full article...)
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Zigrasimecia hoelldobleri worker
Zigrasimecia is an extinct genus of ants which existed in the Cretaceous period approximately 98 million years ago. The first specimens were collected from Burmese amber in Kachin State, 100 kilometres (62 mi) west of Myitkyina town in Myanmar. In 2013, palaeoentomologists Phillip Barden and David Grimaldi published a paper describing and naming Zigrasimecia tonsora. They described a dealate female with unusual features, notably the highly specialized mandibles. Other features include large ocelli, short scapes, 12 antennomeres, small eyes, and a clypeal margin that has a row of peg-like denticles. The genus Zigrasimecia was originally incertae sedis (uncertain placement) within Formicidae until a second species, Zigrasimecia ferox, was described in 2014, leading to its placement in the subfamily Sphecomyrminae. Later, it was considered to belong to the distinct subfamily Zigrasimeciinae.
Due to the highly specialized mandibles, scientists believe that the ants exhibited habits no longer seen in extant ants. The highly movable head suggests that mobility was an important factor for them (probably for feeding behavior), and the rugose projections may have played a major role in nest excavation because the mandibles would have prevented such activity. Zigrasimecia most likely interacted with the extinct ant genus Gerontoformica through conflict and probably shared some of their ecological niches. The mandibles of these ants were probably used for mechanical interactions with food, and they may also have served as traps for potential arthropod prey such as mites and small flies. Zigrasimecia was possibly a generalist predator. (Full article...)
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Alice E. Gray (June 7, 1914 – April 27, 1994) was an American entomologist and origamist. She worked as an entomologist at the American Museum of Natural History (AMNH) in New York for 43 years, writing, illustrating, and creating large models of insects. Known as the "Bug Lady", she conducted outreach and education in the museum, in local schools, and appeared on The Tonight Show. She began practicing origami first as an extension of her interest in insects, starting a tradition of using origami creatures to decorate the museum's Christmas tree. In the 1960s, she became more involved with the origami community and, in 1978, co-founded the Friends of the Origami Center of America in New York with Lillian Oppenheimer and Michael Shall, now known as OrigamiUSA. (Full article...)
Pittsfordipterus was a basal ("primitive") genus that was distinguished from the more derived adelophthalmids by the specialization of its genital operculum (a plate-like segment which contains the genital aperture) and its long and narrow eyes, being Bassipterus' closest relative. With an estimated length of 6 cm (2.4 in), Pittsfordipterus was one of the smallest adelophthalmids. (Full article...)
Snakeflies are a group of predatoryinsects comprising the orderRaphidioptera with two extant families: Raphidiidae and Inocelliidae, consisting of roughly 260 species. In the past, the group had a much wider distribution than it does now; snakeflies are found in temperate regions worldwide but are absent from the tropics and the Southern Hemisphere. Recognisable representatives of the group first appeared during the Early Jurassic. They are a relict group, having reached their apex of diversity during the Cretaceous before undergoing substantial decline.
An adult snakefly resembles a lacewing in appearance but has a notably elongated thorax which, together with the mobile head, gives the group their common name. The body is long and slender and the two pairs of long, membranous wings are prominently veined. Females have a large and sturdy ovipositor which is used to deposit eggs in some concealed location. They are holometabolous insects with a four-stage life cycle consisting of eggs, larvae, pupae and adults. In most species, the larvae develop under the bark of trees. They may take several years before they undergo metamorphosis, requiring a period of chilling before pupation takes place. Both adults and larvae are predators of soft-bodied arthropods. (Full article...)
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Worker policing is a behavior seen in colonies of social hymenopterans (ants, bees, and wasps) whereby worker females eat or remove eggs that have been laid by other workers rather than those laid by a queen. Worker policing ensures that the offspring of the queen will predominate in the group. In certain species of bees, ants and wasps, workers or the queen may also act aggressively towards fertile workers. Worker policing has been suggested as a form of coercion to promote the evolution of altruistic behavior in eusocial insect societies.
Proposed mechanisms for the recognition of worker-laid eggs or active reproductive workers include marker hydrocarbons on the surface of queen-laid eggs, cuticle hydrocarbons on reproductive workers, and recognition of nest-mates. In rare cases, worker-laid eggs carry mimicked queen hydrocarbons and escape policing, a condition known as the anarchic syndrome.
Not all forms of policing require the presence of a queen; it also occurs in a few species of ants which establish a dominance hierarchy of reproductive female workers, where top-ranking individuals reproduce. (Full article...)
Beetles are insects that form the orderColeoptera (/koʊliːˈɒptərə/), in the superorder Holometabola. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 described species, is the largest of all orders, constituting almost 40% of described insects and 25% of all known animal species; new species are discovered frequently, with estimates suggesting that there are between 0.9 and 2.1 million total species. Found in almost every habitat except the sea and the polar regions, they interact with their ecosystems in several ways: beetles often feed on plants and fungi, break down animal and plant debris, and eat other invertebrates. Some species are serious agricultural pests, such as the Colorado potato beetle, while others such as Coccinellidae (ladybirds or ladybugs) eat aphids, scale insects, thrips, and other plant-sucking insects that damage crops. Some others also have unusual characteristics, such as fireflies, which use a light-emitting organ for mating and communication purposes.
Beetles typically have a particularly hard exoskeleton including the elytra, though some such as the rove beetles have very short elytra while blister beetles have softer elytra. The general anatomy of a beetle is quite uniform and typical of insects, although there are several examples of novelty, such as adaptations in water beetles which trap air bubbles under the elytra for use while diving. Beetles are holometabolans, which means that they undergo complete metamorphosis, with a series of conspicuous and relatively abrupt changes in body structure between hatching and becoming adult after a relatively immobile pupal stage. Some, such as stag beetles, have a marked sexual dimorphism, the males possessing enormously enlarged mandibles which they use to fight other males. Many beetles are aposematic, with bright colors and patterns warning of their toxicity, while others are harmless Batesian mimics of such insects. Many beetles, including those that live in sandy places, have effective camouflage.
... that the horse fly Scaptia beyonceae was named after singer and actress Beyoncé Knowles because of its striking golden behind?
... that the female sand waspAmmophila sabulosa digs burrows in sandy ground, provisioning each burrow with a food supply of paralysed caterpillars, always laying one egg on the first caterpillar?
Image 12The house centipedeScutigera coleoptrata has rigid sclerites on each body segment. Supple chitin holds the sclerites together and connects the segments flexibly. Similar chitin connects the joints in the legs. Sclerotised tubular leg segments house the leg muscles, their nerves and attachments, leaving room for the passage of blood to and from the hemocoel (from Arthropod exoskeleton)
Image 13This Zoea-stage larva is hardly recognisable as a crab, but each time it sheds its cuticle it remodels itself, eventually taking on its final crab form (from Arthropod exoskeleton)
Image 14Some of the various hypotheses of myriapod phylogeny. Morphological studies (trees a and b) support a sister grouping of Diplopoda and Pauropoda, while studies of DNA or amino acid similarities suggest a variety of different relationships, including the relationship of Pauropoda and Symphyla in tree c. (from Myriapoda)
Image 16Formation of anterior segments across arthropod taxa based on gene expression and neuroanatomical observations, Note the chelicera(Ch) and chelifore(Chf) arose from somite 1 and thus correspond to the first antenna(An/An1) of other arthropods. (from Chelicerata)
Image 19Reconstruction of Mollisonia plenovenatrix, the oldest known arthropod with confirmed chelicerae (from Chelicerata)
Image 20Mature queen of a termite colony, showing how the unsclerotised cuticle stretches between the dark sclerites that failed to stretch as the abdomen grew to accommodate her ovaries (from Arthropod exoskeleton)
Image 22In honeypot antrepletes, the abdomens of the workers that hold the sugar solution grow vastly, but only the unsclerotised cuticle can stretch, leaving the unstretched sclerites as dark islands on the clear abdomen (from Arthropod exoskeleton)
Image 23 This fully-grown robber crab has tough fabric forming its joints, delicate biomineralized cuticle over its sensory antennae, optic-quality over its eyes, and strong, calcite-reinforced chitin armouring its body and legs; its pincers can break into coconuts (from Arthropod exoskeleton)
Image 24Body structure of a typical crustacean – krill (from Crustacean)
Image 30Crab larva barely recognisable as a crab, radically changes its form when it undergoes ecdysis as it matures (from Arthropod exoskeleton)
Image 31Ghost crab, showing a variety of integument types in its exoskeleton, with transparent biomineralization over the eyes, strong biomineralization over the pincers, and tough chitin fabric in the joints and the bristles on the legs (from Arthropod exoskeleton)
The citrus root weevil (Diaprepes abbreviatus) is a major agricultural pest weevil in several Caribbean countries and the U.S. state of Florida. The larvae feed on the roots of the host plant for several months. They often eat the taproot of the plant, which can kill it by depriving it of water and nutrients or by making it vulnerable to infection by fungi, or water moulds.
Leptosia nina, known as the psyche, is a species of butterfly in the family Pieridae (the sulphurs, yellows and whites), found in the Indian subcontinent, southeastern Asia, and Australia. It has a small wingspan of 2.5 to 5 cm (1 to 2 in). The upper side of the otherwise white forewing has a large, somewhat pear-shaped, black spot; this spot is also present on the underside which is scattered with greenish dots and speckles, sometimes arranged in bands. This L. nina butterfly was photographed in Kerala, India.
Zonocerus variegatus, the variegated grasshopper, is a species of grasshopper in the family Pyrgomorphidae native to tropical western and central Africa. It feeds on a wide variety of plant foods and causes damage to crops, particularly cassava, groundnuts and vegetables, as well as transmitting diseases caused by mosaic viruses between plants. This Z. variegatus grasshopper was photographed in the Bobiri Forest in Ghana.
The Forest scorpion (Cercophonius squama) is a scorpion native to southeastern Australia and Tasmania. The body is 25 to 40 millimetres (0.98 to 1.57 in) long, and coloured creamy yellow to orange brown with dark brown variegations. The legs are yellow with some dark brown pigment.
A mole cricket, an insect belonging to the Gryllotalpidaefamily. Mole crickets are common insects, found on every continent except Antarctica, but because they are nocturnal and spend nearly all their lives underground in extensive tunnel systems, they are rarely seen. This specimen is likely to be Gryllotalpa brachyptera and is about 3.5 cm (1.4 in.) in size.
Argiope trifasciata, the banded garden or banded orb-weaving spider, is a species of arachnid in the family Araneidae. It is native to North and South America but has spread to other parts of the world. This ventral view of a female A. trifasciata shows her in the centre of her web, which can reach a diameter of 60 cm (24 in). The function of the zig-zag web decorations is unclear, but they may serve to make the spider appear larger or to act as a warning sign.
The Ozyptila praticola species of crab spider is found throughout Europe and the Middle East. They do not build webs to trap prey, but are active hunters. Crab spiders are so named because of their first two pairs of legs, which are held out to the side giving them a crab-like appearance. Also, like crabs, these spiders move sideways and backwards more easily than forwards.
Anthidium florentinum, a species of bee in the family Megachilidae. Bees are flying insects closely related to wasps and ants that are involved in pollination. There are nearly 20,000 known species of bees in seven recognized biological families. Bees are found on every continent except Antarctica, in every habitat on the planet that contains insect-pollinated flowering plants. Bees range in size from tiny stingless bee species whose workers are less than 2 millimetres (0.08 in) long, to Megachile pluto, whose females can attain a length of 39 millimetres (1.54 in).
Poli's stellate barnacle (Chthamalus stellatus) is a species of acorn barnacle common on rocky shores in South West England, Ireland, and Southern Europe. It is named after Italian scientist Giuseppe Saverio Poli. Depending upon environmental conditions and the amount of food available, it can reach up to 14 mm (0.55 in) in diameter.
A lithograph by Sidney Hall, published in Urania's Mirror, depicting the constellation Scorpius. One of the 48 constellations identified by the Greek astronomer Ptolemy in the second century, Scorpius lies between Libra to the west and Sagittarius to the east. It contains 18 main stars, the brightest of which is Antares. Although frequently identified as a scorpion, this constellation has also been likened to a "leaning coconut tree" (Java) or "Maui's fishhook" (Hawaii).
The orb-weaver spiders (family Araneidae) are the familiar builders of spiral wheel-shaped webs often found in gardens, fields and forests. The family is a large one, including over 2800 species in over 160 genera worldwide, making it the third largest known (behind Salticidae and Linyphiidae). The web has always been thought of as an engineering marvel.
A honeycomb is a mass of hexagonal prismaticwax cells built by honey bees in their hives to contain their larvae and stores of honey and pollen. Honey bees consume about 8.4 lb (3.8 kg) of honey to secrete 1 lb (0.5 kg) of wax. As such, many beekeepers attempt to conserve honeycombs where possible.
Xylotrupes socrates (Siamese rhinoceros beetle, or "fighting beetle"), male, on a banana leaf. This scarab beetle is particularly known for its role in insect fighting in Northern Laos and Thailand.
The light blue soldier crab (Mictyris longicarpus) inhabits beaches in the Indo-Pacific region. Soldier crabs filter sand or mud for microorganisms. They congregate during the low tide, and bury themselves in a corkscrew pattern during high tide, or whenever they are threatened.
A European paper wasp (Polistes dominula) heating a bubble of regurgitated fluid in the sunlight. This is a common practice among many winged insects, and it is believed to be a way to facilitate digestion or to cool themselves off.
The red rock crab (Grapsus grapsus) is one of the most common crabs along the western coast of the Americas. Adults are quite variable in color, including brownish-red, mottled or spotted brown, pink, yellow, bright orange and red. It feeds on algae primarily, sometimes sampling other plant matter and dead animals.
The Meadow Argus (Junonia villida) is a species of butterfly native to Australasia. Its brown wings are each covered with two distinctive black and blue eyespots as well as white and orange marks that appear on the edge of the wings. Males and females are similar in appearance and size, with females being slightly larger.
The longtail tadpole shrimp (Triops longicaudatus) is a freshwater crustacean resembling a miniature horseshoe crab. It is one of the oldest animal species still in existence. Like its relative Triops cancriformis, the longtail tadpole shrimp is considered a living fossil because its basic prehistoric morphology has changed little in the last 70 million years, exactly matching ancient fossils.
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