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CrustaceansArthropodaInsectsCambrianCuticleEvolutionaryCentipedesSpidersSpeciesExoskeletonMillipedesSegmentsGroupNervousInsectBackMarineGroupsEarlyRangeRecordHeadStem groupExtinctInvertebratesTrilobitaHomologousAntennaeMandibulatesTraitsCavityDistinctPairFoundIdenticalCharactersMandiblesFormStructures
Crustaceans2
  • However, due to the general features and the discovery of fossils from this group in Cambrian rocks, a 2010 study suggested that they may have given rise to the mandibulates, the group that includes the myriapods (centipedes, millipedes and the like), crustaceans, and hexapods (insects, etc. (wikipedia.org)
  • Arthropods form the phylum Arthropoda , which includes the insects , arachnids , myriapods, and crustaceans . (alchetron.com)
Arthropoda1
  • Insects ( Latin insecta ), also called insects or kerfe , are the species-richest class of arthropods (Arthropoda) and at the same time, with an absolute majority, the most species-rich class of animals at all. (zxc.wiki)
Insects3
  • Vampires include some insects and other arthropods, a few mollusks, some fishes and birds on occasion. (snexplores.org)
  • The smallest free-living insects are dwarf beetles with a body length of 0.4 mm (even smaller figures are based on measurement errors). (zxc.wiki)
  • The largest known insects are stick insects with a body length of about 33 centimeters and the giant longhorn beetle Titanus giganteus with a body length of 15 centimeters. (zxc.wiki)
Cambrian5
  • Euthycarcinoidea are an enigmatic group of extinct possibly amphibious arthropods that ranged from Cambrian to Triassic times. (wikipedia.org)
  • This would help to close the gap between the earliest body fossils of crown-group myriapods in the Silurian and molecular clock data suggesting a divergence from their closest relatives during the Ediacaran or Cambrian. (wikipedia.org)
  • Fossil impressions of euthycarcinoid postabdomens in association with Protichnites trackways in Cambrian intertidal/supratidal deposits also suggest that euthycarcinoids may have been the first arthropods to walk on land. (wikipedia.org)
  • It has been suggested that the biofilms and microbial mats that covered much of the vast tidal flats during the Cambrian Period in North America may have provided the nourishment that lured these arthropods onto the land. (wikipedia.org)
  • The evolutionary ancestry of arthropods dates back to the Cambrian period. (alchetron.com)
Cuticle2
  • Arthropods are characterized by their jointed limbs and cuticle made of chitin , often mineralised with calcium carbonate . (alchetron.com)
  • The rigid cuticle inhibits growth, so arthropods replace it periodically by moulting . (alchetron.com)
Evolutionary1
  • In fact, the nervous system has been considered 'a particularly suitable organ in which to search for characters to reconstruct evolutionary relationships between the major arthropod groups' [ 2 ]. (biomedcentral.com)
Centipedes2
  • [3] There are approximately 12,000 named species classified into 16 orders and around 140 families , making Diplopoda the largest class of myriapods , an arthropod group which also includes centipedes and other multi-legged creatures. (wikipedia.org)
  • Millipedes can be distinguished from the somewhat similar but only distantly related centipedes (class Chilopoda), which move rapidly, are venomous , carnivorous , and have only a single pair of legs on each body segment. (wikipedia.org)
Spiders2
  • Their vision relies on various combinations of compound eyes and pigment-pit ocelli: in most species the ocelli can only detect the direction from which light is coming, and the compound eyes are the main source of information, but the main eyes of spiders are ocelli that can form images and, in a few cases, can swivel to track prey. (alchetron.com)
  • To further test this hypothesis, we investigated neurogenesis in Pycnogonida, or sea spiders, a group of marine arthropods with close affinities to euchelicerates. (biomedcentral.com)
Species1
  • Estimates of the number of arthropod species vary between 1,170,000 and 5 to 10 million and account for over 80% of all known living animal species. (alchetron.com)
Exoskeleton3
  • An arthropod (from Greek arthro- , joint + podos , foot) is an invertebrate animal having an exoskeleton (external skeleton), a segmented body, and jointed appendages (paired appendages ). (alchetron.com)
  • Its primary defence mechanism is to curl into a tight coil, thereby protecting its legs and other vital delicate areas on the body behind a hard exoskeleton. (wikipedia.org)
  • The exoskeleton forms the outer layer of the insect's body. (zxc.wiki)
Millipedes3
  • Most millipedes have very elongated cylindrical or flattened bodies with more than 20 segments, while pill millipedes are shorter and can roll into a tight ball. (wikipedia.org)
  • Most millipedes defend themselves with a variety of chemicals secreted from pores along the body, although the tiny bristle millipedes are covered with tufts of detachable bristles. (wikipedia.org)
  • Among myriapods, millipedes have traditionally been considered most closely related to the tiny pauropods , although some molecular studies challenge this relationship. (wikipedia.org)
Segments4
  • The cephalon consisted of two segments and included mandibles, antennae and presumed eyes. (wikipedia.org)
  • The arthropod body plan consists of segments, each with a pair of appendages. (alchetron.com)
  • Like their exteriors, the internal organs of arthropods are generally built of repeated segments. (alchetron.com)
  • Between the individual segments there are elastic membranes, the intersegmental membranes , which enable the segments to move relative to one another and to change the volume of the body during egg production, eating or breathing. (zxc.wiki)
Group1
  • 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. (alchetron.com)
Nervous3
  • combines features of central nervous system development that have been hitherto described separately in different arthropod taxa. (biomedcentral.com)
  • Nervous system development and adult neuroanatomy of arthropods provide 'a wealth of valuable characters that can be used for phylogenetic inferences' [ 1 ]. (biomedcentral.com)
  • The basic architecture of the arthropod central nervous system is most evident during embryonic development. (biomedcentral.com)
Insect3
  • The word "insect" (from Latin īnsectum "incised") was Germanized in the 18th century and therefore means "incised (animal)", which refers to the strongly separated body parts. (zxc.wiki)
  • Depending on their way of life, the body of the insect can be elongated, flattened or more or less spherical. (zxc.wiki)
  • the largest insect ever, with a wingspan up to 71cm and body length of 43cm. (wlgf.org)
Back1
  • Damselflies hold their wings folded back above their bodies. (wlgf.org)
Marine1
Groups2
  • Likewise, the relationships between various arthropod groups are still actively debated. (alchetron.com)
  • The developmental processes of early neurogenesis show distinct features in the major arthropod groups. (biomedcentral.com)
Early1
  • Studies on early neurogenesis have had considerable impact on the discussion of the phylogenetic relationships of arthropods, having revealed striking similarities and differences between the major lineages. (biomedcentral.com)
Range2
  • Arthropods range in size from the microscopic crustacean Stygotantulus up to the Japanese spider crab . (alchetron.com)
  • Arthropods also have a wide range of chemical and mechanical sensors, mostly based on modifications of the many setae (bristles) that project through their cuticles . (alchetron.com)
Record1
  • Observation Little book to record observations of small objects with naked eye (actual size) & magnification . (homeofbob.com)
Head2
  • The euthycarcinoid body was divided into a cephalon (head), preabdomen, and postabdomen. (wikipedia.org)
  • The enormous compound eyes on a dragonfly's head touch each other above the head, whereas the eyes on a damselfly are clearly separated to the sides of the head. (wlgf.org)
Stem group1
  • Morphological correspondences with stem group arthropods and alignments of homologous gene expression patterns with those of extant panarthropods demonstrate that cephalic domains of C. catenulum predate the evolution of the euarthropod head yet correspond to neuromeres defining brains of living chelicerates and mandibulates. (bvsalud.org)
Extinct2
Invertebrates1
Trilobita1
Homologous1
  • Such body structures are usually serially homologous. (ncse.ngo)
Antennae2
  • The cephalon consisted of two segments and included mandibles, antennae and presumed eyes. (wikipedia.org)
  • They are also characterized by the presence of one or two pairs of antennae and have groups of eight cells in the retinula of the compound eye (if one exists). (newworldencyclopedia.org)
Mandibulates2
  • The mandibulates constitute the largest and most varied arthropod group. (newworldencyclopedia.org)
  • Mandibulates also differ from chelicerates by having three distinct body regions: head, thorax, and abdomen (the prosoma of chelicerates is not a fusion of head and thorax, although often called a cephalothorax). (newworldencyclopedia.org)
Traits2
  • In one species of shore crab (Brachyura, Varunidae), a center that supports long-term visual habituation and that matches the reniform body's morphology has been claimed as a homolog of the insect mushroom body despite lacking traits that define it as such. (bvsalud.org)
  • The discovery in a related species of shore crab of a mushroom body possessing those defining traits renders that interpretation unsound. (bvsalud.org)
Cavity1
  • Nitrogenous wastes may be lost by diffusion through the entire body or into the pseudocoelom (body cavity), where they are removed by specialized cells. (eatatnakama.com)
Distinct2
  • Two phenotypically distinct, coexisting centers cannot both be homologs of the insect mushroom body. (bvsalud.org)
  • Their head is short, not distinct from the neck, the body is cylindrical, elongated and thin, and finally, the tail is short. (monaconatureencyclopedia.com)
Pair1
  • A mandible is either of a pair of arthropod mouthparts used for biting, cutting, and holding food. (newworldencyclopedia.org)
Found1
Identical2
  • The fact that body plans as diverse as a fruit fly and a mouse should be determined by an almost identical underlying system of regulatory genes was an entirely unexpected discovery! (ncse.ngo)
  • The body is covered by scales, all identical, very smooth and much imbricate. (monaconatureencyclopedia.com)
Characters1
  • However, a 2020 study identified several characters, including compound eyes and various details of the preoral chamber, that suggested instead a position as the closest relatives of living myriapods. (wikipedia.org)
Mandibles2
Form1
  • 35] The eyes of horseshoe crabs can detect movement but not form images. (eatatnakama.com)
Structures1
  • Thus there is a colinear sequence between the genes on the chromosome and the structures along the anterior-posterior axis of the body that they affect (Graham, Papalopulu and Krumlauf, 1989. (ncse.ngo)