• genus
  • There are fifteen species belonging to the genus Eurypterus, the most common of which is Eurypterus remipes, the first eurypterid fossil discovered and the state fossil of New York. (wikipedia.org)
  • He consequently identified the fossil as a catfish of the genus Silurus. (wikipedia.org)
  • In 1958, several species distinguishable by closer placed eyes and spines on their swimming legs were split off into the separate genus Eiropterus by Erik Kjellesvig-Waering. (wikipedia.org)
  • Anomalocaris ("abnormal shrimp") is an extinct genus of anomalocaridid, a family of animals thought to be closely related to ancestral arthropods. (wikipedia.org)
  • Some entomologists have suggested a relationship to the Baltic Eocene fossil ant genus Prionomyrmex based on morphological similarities, but this interpretation is not widely accepted by the entomological community. (wikipedia.org)
  • In 1960 Russian paleontologists described specimens they found in the Norilsky region of Siberia and labelled Opabinia norilica, but these fossils were poorly preserved, and Whittington did not feel they provided enough information to be classified as members of the genus Opabinia. (wikipedia.org)
  • Indeed, in the most famous genus, North America 's Stegosaurus , their brain was only the size of a walnut whereas their body was the size of a van! (blogspot.nl)
  • Perhaps the best-known genus of eurypterid is Eurypterus, of which around 16 fossil species are known. (wikipedia.org)
  • Correctly recognizing the arthropod nature of the fossil, zoologist James DeKay in 1825 assigned its taxonomic classification as Genus Eurypterus and its species designation as remipes, although he thought it was a crustacean. (blogspot.fr)
  • Trilobites
  • Trilobites are an extinct group of arthropods that first appeared early in the Cambrian Period, and met their demise at the end of the Permian Period. (trilobites.com)
  • Trilobites were stunningly complex and beautiful animals, which is why their fossilized remains are extremely sought-after by serious fossil collectors. (trilobites.com)
  • And due to their unique anatomy and bizarre body designs, trilobites are also admired by untrained amateurs. (trilobites.com)
  • Fossil trilobites have been found in Native American excavations - they were drilled and used in ritualistic jewelry hundreds of years ago. (trilobites.com)
  • It is not that unusual to find enrolled trilobites in the fossil record. (trilobites.com)
  • Despite all these changes and adaptations, trilobites did not stray far away from their original body plan during millions of years of evolution. (trilobites.com)
  • Tracks and trails of trilobites have long been recognized as trace fossils. (trilobites.com)
  • Trilobites are favorites of fossil collectors everywhere due to their unique design and varied forms of preservation. (trilobites.com)
  • One of the best-known groups of fossil animal are the trilobites ('three-lobed'), this name deriving from the distinctive three-lobed structure of their body, which consists of the cephalon (head shield), the thorax, and the pygidium (tail shield). (blogspot.co.uk)
  • They were initially deemed to be ancient, three-lobed clam-like seashells (and were duly dubbed Concha triloba ), because these particular trilobite fossils showed only the animals' dorsal side (thereby concealing the fact that trilobites actually possessed legs - lots of legs, in fact! (blogspot.co.uk)
  • The matter remained contentious until American palaeontologist Charles D. Walcott resolved it in a very convincing manner - by skilfully and painstakingly using a hacksaw to open up no fewer than 3,500 fossils of curled-up trilobites, thereby revealing the presence of their jointed legs, and, in turn, these hitherto-baffling beasts' true nature as arthropods. (blogspot.co.uk)
  • The first eyes appeared about 543 million years ago - the very beginning of the Cambrian period - in a group of trilobites called the Redlichia. (newscientist.com)
  • thorax
  • the segments tend to be fused together in groups to create distinct body regions such as head, thorax, and abdomen. (scholastic.com)
  • The legs, eyes and mouth are all located on the prosoma and it serves as both a head and a thorax. (wikipedia.org)
  • They are segmented animals, united by a common body plan comprising 20 body segments (rarely 21), and divided into a head, thorax, and abdomen. (wikipedia.org)
  • Trilobite
  • The body of the trilobite was covered by a calcareous exoskeleton which, as a rule, is divided lengthwise into three "lobes", hence the name "trilobite. (trilobites.com)
  • Bearing in mind how zoologically familiar they are today and how their taxonomic identity as arthropods is indisputable, it may come as something of a surprise to learn that the first trilobite fossils to attract notable scientific attention, during the 1700s, incited considerable controversy as to what type of creature they represented, resulting in some exceedingly bizarre notions being aired in all seriousness. (blogspot.co.uk)
  • And their appearance in the fossil record is strikingly sudden - trilobite ancestors from 544 million years ago don't have eyes. (newscientist.com)
  • Cambrian
  • Its discovery was astonishing because previously, anomalocaridids were known only from exceptionally well-preserved fossil beds (Lagerstätten) from the Cambrian, 100 million years earlier. (wikipedia.org)
  • In 2011, six fossils of compound eyes dated to the Cambrian period (515 million years ago) were recovered from an archaeological dig at Emu Bay on Kangaroo Island, Australia. (wikipedia.org)
  • The Anomalocaridids comprise a group of very early marine animals known primarily from fossils found in Cambrian deposits in China, United States, Canada, Poland and Australia. (wikipedia.org)
  • The earliest thylacocephalan fossil is thought to date from the lower Cambrian, while the class has a definite presence in Lower Silurian marine communities. (wikipedia.org)
  • Opabinia regalis is an extinct, stem group arthropod found in the Middle Cambrian Burgess Shale Lagerstätte of British Columbia, Canada. (wikipedia.org)
  • In the 1970s there was an ongoing debate about whether multi-celled animals appeared suddenly during the Early Cambrian, in an event called the Cambrian explosion, or had arisen earlier but without leaving fossils. (wikipedia.org)
  • Later the discovery of a whole series of similar lobopod animals, some with closer resemblances to arthropods, and the development of the idea of stem groups suggested that the Early Cambrian was a time of relatively fast evolution but one that could be understood without assuming any unique evolutionary processes. (wikipedia.org)
  • The fossil record of myriapods reaches back into the late Silurian, although molecular evidence suggests a diversification in the Cambrian Period, and Cambrian fossils exist which resemble myriapods. (wikipedia.org)
  • Global but exclusively marine in distribution, this taxonomic class of arthropods was one of the earliest, with the first-known representatives in the fossil record dating back approximately 540-520 million years to the early Cambrian Period (though it is suspected that there may well have been earlier forms as yet unrepresented by documented fossils dating as far back as 700 million years, to the pre-Cambrian). (blogspot.co.uk)
  • gills
  • Eyes = Gut == Gills Opabinia looked so strange that the audience at the first presentation of Whittington's analysis laughed. (wikipedia.org)
  • As in other arthropods, a true endoskeleton is absent, but the body does have an endoskeletal structure made up of cartilaginous plates that support the book gills. (wikipedia.org)
  • Xiphosurans have well-developed circulatory systems, with numerous arteries that send blood from the long tubular heart to the body tissues, and then to two longitudinal sinuses next to the gills. (wikipedia.org)
  • Chelicerates
  • Fossil Taxa and Relationships of Chelicerates" pp. 303-311 in G. D. Edgecombe (ed. (berkeley.edu)
  • Chelicerates' bodies consist of two tagmata, sets of segments that serve similar functions: the foremost one, called the prosoma or cephalothorax, and the rear tagma is called the opisthosoma or abdomen. (wikipedia.org)
  • crustacean
  • The Thylacocephala (from the Greek θύλακος or thylakos, meaning "pouch", and κεφαλή or cephalon meaning "head") are a unique group of extinct arthropods, with possible crustacean affinities. (wikipedia.org)
  • abdomen
  • Their bodies are covered with a tough cuticle, but do not contain any crystalline biominerals, and are divided into an anterior prosoma and a posterior opisthosoma, or abdomen. (wikipedia.org)
  • The nervous system of an insect centers around a nerve cord that runs from the head to the abdomen along the underside of the body. (everythingabout.net)
  • Burgess Shale
  • The first fossils of Anomalocaris were discovered in the Ogygopsis Shale by Joseph Frederick Whiteaves, with more examples found by Charles Doolittle Walcott in the famed Burgess Shale. (wikipedia.org)
  • Charles Doolittle Walcott found in the Burgess Shale nine almost complete fossils of Opabinia regalis and a few of what he classified as Opabinia media, and published a description of all of these in 1912. (wikipedia.org)
  • Based on the number of individuals, Waptia fieldensis is the third most abundant arthropod from the Burgess Shale Formation, with thousands of specimens collected. (wikipedia.org)
  • Waptia fieldensis was one of the first fossils discovered by Charles D. Walcott from the Burgess Shale in August 1909. (wikipedia.org)
  • absent
  • Although originally interpreted as an anomalocaridid-like arthropod, some recent studies suggest that it may represent an anomalocaridid: if so it would extend the group's record by some hundred million years: the non-mineralised anomalocaridid structure means they are absent from the intermediate fossil record. (wikipedia.org)
  • prosoma
  • The Eurypterus body is broadly divided into two parts: the prosoma and the opisthosoma (in turn divided into the mesosoma and the metasoma). (wikipedia.org)
  • The front portion is the prosoma , where the legs are attached and the eyes and mouth are located. (berkeley.edu)
  • The basic body plan of a horseshoe crab consists of three parts: the prosoma, the opisthosoma and the telson. (wikipedia.org)
  • telson
  • There are a few fossils in which part of the intestine is preserved, and this ends in an opening between the final tergite and the telson, on the underside of the tail. (berkeley.edu)
  • A long telson is present at the end of the body. (wikipedia.org)
  • Also, a pair of ventral eyes is located near the mouth, as well as a cluster of photoreceptors on the telson. (wikipedia.org)
  • large
  • Prionomyrmex ants are characterised by their large size, slender bodies, elongated mandibles and powerful stingers. (wikipedia.org)
  • Anomalocaris had a large head, a single pair of large, compound eyes on stalks comprising approximately 16,000 lenses, and an unusual disk-like mouth. (wikipedia.org)
  • Workers are strictly nocturnal (active mainly at night) but navigate by vision, relying on large compound eyes. (wikipedia.org)
  • The eurypterid shown above ( Pterygotus ) has unusually large compound eyes. (berkeley.edu)
  • Anomalocaridids also had large compound eyes, a feature that they share with arthropods. (wikipedia.org)
  • Some efforts have been made at further classification: Schram split currently known taxa into two orders: Concavicarida Briggs & Rolfe, 1983 which possesses: A large, well developed optic notch A discrete compound eye A fused rostrum 8 to 16 homologous well-demarcated trunk segments diminishing in height anteriorly and posteriorly Order includes Ainiktozoon (Silurian), Harrycaris (Devonian), Concavicaris (Devonian to Carboniferous), Dollocaris (Jurassic). (wikipedia.org)
  • Exceptions include the large and well-developed compound eyes of Scutigera The mouthparts lie on the underside of the head, with an "epistome" and labrum forming the upper lip, and a pair of maxillae forming the lower lip. (wikipedia.org)
  • The eyes are large and well developed, the mandibles are subtriangular but poorly preserved, and a sting is present on examined A. systenus fossils. (wikipedia.org)
  • The stomach secretes digestive enzymes, and is attached to an intestine and two large caeca that extend through much of the body, and absorb the nutrients from the food. (wikipedia.org)
  • segments
  • The main part of the body was typically about 5 millimetres (0.20 in) wide and had 15 segments, on each of which there were pairs of lobes (flaps) pointing downwards and outwards. (wikipedia.org)
  • Millipedes differ from the other groups in having their body segments fused into pairs, giving the appearance that each segment bears two pairs of legs, while the other three groups have a single pair of legs on each body segment. (wikipedia.org)
  • They are distinguished by the fusion of each pair of body segments into a single unit, giving the appearance of having two pairs of legs per segment. (wikipedia.org)
  • group
  • One classification scheme has Schinderhannes classified basally to the crown arthropods, but closer to that group than Anomalocaris. (wikipedia.org)
  • Briggs & Rolfe, working on fossils from Australia's Devonian deposits were unable to attribute certain specimens to a known group, and created an order of uncertain affinities, the Concavicarida, to accommodate them. (wikipedia.org)
  • The new findings are based on a three-inch-long fossil arthropod known as Fuxianhuia protensa, found in what is now China's Yunnan Province and were described online October 10 in Nature ( Scientific American is part of Nature Publishing Group). (scientificamerican.com)
  • Another major group of arthropods, however, called the branchiopods (which includes brine shrimp and Daphnia water fleas ) that emerged later, have much simpler brains with only two optic neuropils that are not connected like those in Fuxianhuia . (scientificamerican.com)
  • The group has the open circulatory system typical of arthropods, in which a tube-like heart pumps blood through the hemocoel, which is the major body cavity. (wikipedia.org)
  • Typically
  • Typically, arthropods have reproductive systems that are either distinctly male or female, and therefore reproduce sexually. (scholastic.com)
  • The name "millipede" is a compound word formed from the Latin roots millia ("thousand") and pes (gen. pedis) ("foot"), although millipedes typically have between 36 and 400 legs. (wikipedia.org)
  • Typically the cord is equipped with a pair of ganglia, or nerve centers, for each segment of the body. (everythingabout.net)
  • myriapod
  • The oldest unequivocal myriapod fossil is of the millipede Pneumodesmus newmani, from the late Silurian (428 million years ago). (wikipedia.org)
  • ventral
  • Scientists believe the two ventral eyes aid in the orientation of the horseshoe crab when swimming. (wikipedia.org)
  • specimen
  • The specimen had no wings and small portions of its legs and eyes were faintly preserved. (wikipedia.org)
  • Macabeemyrma ovata is known only from a single fossil specimen: a mostly complete adult queen, preserved as a compression fossil in fine-grained shale. (wikipedia.org)
  • If the proportions between body length and chelicerae match those of other giant pterygotids, such as Acutiramus and Pterygotus where the ratio between claw size and body length is relatively consistent, the specimen of Jaekelopterus that possessed the chelicera in question would have measured 233 and 259 (average 246) centimetres in length. (wikipedia.org)
  • The holotype specimen is a partial queen which is incomplete, with one forewing and the head fairly preserved, and the other isolated body portions indistinct. (wikipedia.org)
  • The holotype fossil is less than one meter long, although this specimen appears to be a juvenile, and it is possible that Bambiraptor is really just a juvenile Saurornitholestes. (wikia.com)
  • soft-bodied
  • Opabinia was a soft-bodied animal, averaging about 5.7 cm in length (excluding proboscis), and its segmented body had lobes along the sides and a fan-shaped tail. (wikipedia.org)
  • Before eyes, life was gentler and tamer, dominated by sluggish soft-bodied worms lolling around in the sea. (newscientist.com)
  • Eurypterus
  • Eurypterus is by far the most well-studied and well-known eurypterid and its fossil specimens probably represent more than 90 % of all known eurypterid specimens. (wikipedia.org)
  • The first fossil of Eurypterus was found in 1818 by S. L. Mitchill, a fossil collector. (wikipedia.org)
  • Eurypterus fossils often occur in similar sizes in a given area. (wikipedia.org)
  • Eurypterus remipes was eventually designated the official fossil of the State of New York in 1984, an appropriate choice, attributable to its abundance (more than 10,000 specimens have been recovered), and since the majority of productive eurypterid-bearing regions of the world are found within the state's borders. (blogspot.fr)
  • This fossil of Eurypterus remipes, over 400 million years old, is entombed within a dolostone slab of the Phelps Waterlime. (blogspot.fr)
  • mistakenly
  • the fossils were mistakenly identified as "shrimp", but always with their "heads" missing), the mouth was thought to have been a fossilized jellyfish called Peytoia, and the body, thought to be a sponge named "Laggania" was not associated with either. (wikipedia.org)
  • pairs
  • The body ended with what looked like a single conical segment bearing three pairs of overlapping lobes that pointed up and out, forming a tail like a V-shaped double fan. (wikipedia.org)
  • mandibles
  • These ants can be identified by their long slender bodies, powerful stingers and elongated mandibles. (wikipedia.org)
  • The ant has a long stinger, the body is slender and, like Prionomyrmex, has elongated mandibles. (wikipedia.org)
  • ants
  • Fossil Prionomyrmecini ants were once found throughout Europe, possibly nesting in trees and preferring jungle habitats. (wikipedia.org)
  • Fossil Prionomyrmecini ants existed in Europe during the Eocene and Late Oligocene. (wikipedia.org)
  • Fossils of Avitomyrmex, along with other extinct Myrmeciinae ants were first studied and described by Bruce Archibald, Stefan Cover and Corrie Moreau of the Museum of Comparative Zoology in Cambridge, Massachusetts. (wikipedia.org)