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Metapeltidium
Peltidium is a prodorsal shield found in animals of the subphylum Chelicerata, in the phylum Arthropoda. In some groups (Schizomida, Palpigradi, Solpugida and Opiliones The Opiliones (formerly Phalangida) are an Order (biology), order of arachnids, Common name, colloquially known as harvestmen, harvesters, harvest spiders, or daddy longlegs (see below). , over 6,650 species of harvestmen have been discovered w ...), the peltidium, also known as the schizopeltid, can be subdivided into the propeltidium, a carapace-like shield that covers the proterosoma, which comprises the fused acron (protocerebral region) and first four segments, and two free segments, the mesopeltidium and metapeltidium (Online Dictionary of Invertebrate Zoology). External links Online Dictionary of Invertebrate Zoology References {{reflist Chelicerate anatomy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chelicerata
The subphylum Chelicerata (from Neo-Latin, , ) constitutes one of the major subdivisions of the phylum Arthropoda. Chelicerates include the sea spiders, horseshoe crabs, and arachnids (including harvestmen, scorpions, spiders, solifuges, ticks, and mites, among many others), as well as a number of extinct lineages, such as the eurypterids (sea scorpions) and chasmataspidids. Chelicerata split from Mandibulata by the mid-Cambrian, as evidenced by stem-group chelicerates like Habeliida and '' Mollisonia'' present by this time. The surviving marine species include the four species of xiphosurans (horseshoe crabs), and possibly the 1,300 species of pycnogonids (sea spiders), if the latter are indeed chelicerates. On the other hand, there are over 77,000 well-identified species of air-breathing chelicerates, and there may be about 500,000 unidentified species. Like all arthropods, chelicerates have segmented bodies with jointed limbs, all covered in a cuti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthropoda
Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an exoskeleton with a cuticle made of chitin, often mineralised with calcium carbonate, a body with differentiated ( metameric) segments, and paired jointed appendages. 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. They form an extremely diverse group of up to ten million species. Haemolymph is the analogue of blood for most arthropods. An arthropod has an open circulatory system, with a body cavity called a haemocoel through which haemolymph circulates to the interior organs. Like their exteriors, the internal organs of arthropods are generally built of repeated segments. They have ladder-like nervous systems, with paired ventral nerve cords running through all segments and forming paired ganglia in each segment. Their heads are formed by fusion of varying numbers of segments, and their brains are formed by fu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schizomida
Schizomida, also known as sprickets or short-tailed whip-scorpions, is an order of arachnids, generally less than in length. The order is not yet widely studied. E. O. Wilson has identified schizomids as among the "groups of organisms that desperately need experts to work on them." Taxonomy Schizomids are grouped into three families: * Calcitronidae † (fossil; dubious) * Hubbardiidae * Protoschizomidae (2 genera, 15 species) **'' Agastoschizomus'' ** '' Protoschizomus'' About 300 species of schizomids have been described worldwide, most belonging to the Hubbardiidae family. A systematic review including a full catalogue may be found in Reddell & Cokendolpher (1995). The Schizomida is sister to the order Uropygi, the two clades together forming the Thelyphonida (in the broad sense of the name). Based on molecular clock dates, both orders likely originated in the late Carboniferous somewhere in the tropics of Pangea, and the Schizomida underwent substantial diversificat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palpigradi
Palpigradi is an order of very small arachnids commonly known as microwhip scorpion or palpigrades. Description Palpigrades belong to the arachnid class. They are the sister group to Solifugae, no more than in length, and averaging . They have a thin, pale, segmented integument, and a segmented abdomen that terminates in a whip-like flagellum. This is made up of 15 segment-like parts, or "articles", and may make up as much as half the animal's length. Each article of the flagellum bears bristles, giving the whole flagellum the appearance of a bottle brush. The carapace is divided into two plates between the third and fourth leg pair of legs. They have no eyes. As in some other arachnids, the first pair of legs is modified to serve as sensory organs, and are held clear of the ground while walking. Often, however, palpigrades use their pedipalps for locomotion, so that the animal appears to be walking on five pairs of legs. But they do not swing in phase with the walking legs, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solpugida
Solifugae is an order of arachnids known variously as solifuges, sun spiders, camel spiders, and wind scorpions. The order includes more than 1,000 described species in about 147 genera. Despite the common names, they are neither true spiders (order Araneae), nor true scorpions (order Scorpiones). Most species of solifuges live in dry climates and feed opportunistically on ground-dwelling arthropods and other small animals. The largest species grow to a length of , including legs. A number of urban legends exaggerate the size and speed of solifuges, and their potential danger to humans, which is negligible. Etymology The order's name is derived from the Latin ''sol'' meaning "sun" and ''fugere'' meaning "to flee". Put together, it means "those that flee from the sun". These animals have a number of common names, including sun spiders, wind scorpions, wind spiders, red romans, and camel spiders. In Afrikaans, they are known as ''haarskeerders'' ("hair cutters"), and ''baardskeerder ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opiliones
The Opiliones (formerly Phalangida) are an Order (biology), order of arachnids, Common name, colloquially known as harvestmen, harvesters, harvest spiders, or daddy longlegs (see below). , over 6,650 species of harvestmen have been discovered worldwide, although the total number of extant taxon, 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 Phylogenetics, phylogenetic position within the Arachnida is disputed; their closest relatives may be camel spiders (Solifugae ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
