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Pambdelurion
''Pambdelurion'' is an extinct genus of Panarthropoda, panarthropod from the Cambrian aged Sirius Passet site in northern Greenland. Like the morphologically similar ''Kerygmachela'' from the same locality, ''Pambdelurion'' is thought to be closely related to arthropods, combining characteristics of "lobopodians" with those of primitive arthropods. Description ''Pambdelurion'' was large for a Cambrian animal, and is estimated to have reached a length of . ''Omnidens'', an organism from China that closely resembles ''Pambdelurion'' and may even be synonymous with it, reached even larger sizes, estimated to be based on the proportions of ''Pambdelurion''. The head of ''Pambdelurion'' bore a large pair of frontal appendages, homologous to the antennae of onychophorans and frontal appendages of Radiodonta, radiodonts. These frontal appendages were weakly muscled and relatively soft, suggesting they may have served primarily as sensory organs, rather than for grasping prey. Between ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lobopodia
Lobopodians are members of the informal group Lobopodia (), or the formally erected phylum Lobopoda Cavalier-Smith (1998). They are panarthropods with stubby legs called lobopods, a term which may also be used as a common name of this group as well. While the definition of lobopodians may differ between literatures, it usually refers to a group of soft-bodied, marine worm-like fossil panarthropods such as '' Aysheaia'' and '' Hallucigenia''. However, other genera like '' Kerygmachela'' and '' Pambdelurion'' (which have features similar to other groups) are often referred to as “gilled lobopodians”. The oldest near-complete fossil lobopodians date to the Lower Cambrian; some are also known from Ordovician, Silurian and Carboniferous Lagerstätten. Some bear toughened claws, plates or spines, which are commonly preserved as carbonaceous or mineralized microfossils in Cambrian strata. The grouping is considered to be paraphyletic, as the three living panarthropod groups (A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinocaridida
DinocarididaGreek for ''deinos'' "terrible" and Latin for ''caris'' "crab" – sometimes informally spelt Dinocarida, but the second 'id' is linguistically correct – see is a proposed fossil taxon of basal arthropods, which flourished during the Cambrian period and survived up to Early Devonian. Characterized by a pair of frontal appendages and series of body flaps, the name of Dinocaridids (Greek for ''deinos'' "terrible" and Latin for ''caris'' "crab") refers to the suggested role of some of these members as the largest marine predators of their time. Dinocaridids are occasionally referred to as the 'AOPK group' by some literatures, as the group composed of Radiodonta (''Anomalocaris'' and relatives), Opabiniidae (''Opabinia'' and relatives), and the "gilled lobopodians" ''Pambdelurion'' and Kerygmachelidae. It is most likely paraphyletic, with Kerygmachelidae and ''Pambdelurion'' more basal than the clade compose of Opabiniidae, Radiodonta and other arthropods. Anatomy D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Omnidens
''Omnidens'', meaning "all-tooth", is an extinct genus of large Cambrian animal known only from a series of large mouth apparatus and sclerotized talon-like structures, originally mistaken as the mouthparts of anomalocaridids. When first named, it was interpreted as a giant priapulid, but is now considered a panarthropod. Its mouth apparatus closely resembles that of the smaller gilled lobopodian ''Pambdelurion'', indicating it is likely to have been a close relative of that species, potentially even synonymous. With a maximum estimated body length of , ''Omnidens'' is suggested to have been the largest known free-living Cambrian organism. ''Omnidens'' fossils are found in the Maotianshan Shales in the Yunnan Province of southern China, and are especially abundant from the slightly younger Xiaoshiba Lagerstätte locality. History The first-described specimen of ''Omnidens'' was first described in 1994. At the time, it was interpreted as the oral cone of an anomalocaridid, and it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiodonta
Radiodonta is an extinct Order (biology), order of stem-group arthropods that was successful worldwide during the Cambrian period. Radiodonts are distinguished by their distinctive frontal appendages, which are morphologically diverse and were used for a variety of functions. Radiodonts were among the earliest large predators, but they also included sediment sifters and filter feeders. Some of the most famous species of radiodonts are the Cambrian taxa ''Anomalocaris, Anomalocaris canadensis'', ''Hurdia, Hurdia victoria'', ''Peytoia nathorsti'', ''Titanokorys gainesii, Titanokorys gainesi, Cambroraster, Cambroraster falcatus'' and ''Amplectobelua, Amplectobelua symbrachiata''. The later surviving members include the subfamily Aegirocassisinae from the Early Ordovician of Morocco and the Early Devonian member ''Schinderhannes bartelsi'' from Germany. Etymology The name Radiodonta (Latin for ''radius'' "spoke of a wheel" and Greek for ''odoús'' "tooth") refers to the radial arrang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opabinia
''Opabinia regalis'' is an extinct, stem group marine arthropod found in the Middle Cambrian Burgess Shale Lagerstätte (505 million years ago) of British Columbia. ''Opabinia'' was a soft-bodied animal, measuring up to 7 cm in body length, and had a segmented trunk with flaps along its sides and a fan-shaped tail. The head showed unusual features: five eyes, a mouth under the head and facing backwards, and a clawed proboscis that most likely passed food to its mouth. ''Opabinia'' lived on the seafloor, using the proboscis to seek out small, soft food. Free abstract at Fewer than twenty good specimens have been described; 3 specimens of ''Opabinia'' are known from the Greater Phyllopod bed, where they constitute less than 0.1% of the community. When the first thorough examination of ''Opabinia'' in 1975 revealed its unusual features, it was thought to be unrelated to any known phylum, or perhaps a relative of arthropod and annelid ancestors. However, later studies since l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sirius Passet
Sirius Passet is a Cambrian Lagerstätte in Peary Land, Greenland. The Sirius Passet Lagerstätte was named after the Slædepatruljen Sirius, Sirius sledge patrol that operates in North Greenland. It comprises six places in Nansen Land, on the east shore of J.P. Koch Fjord in the far north of Greenland. It was discovered in 1984 by A. Higgins of the Geological Survey of Denmark and Greenland, Geological Survey of Greenland. A preliminary account was published by Simon Conway Morris and others in 1987 and expeditions led by J. S. Peel and Conway Morris have returned to the site several times between 1989 and the present. A field collection of perhaps 10,000 fossil specimens has been amassed. It is a part of the Buen Formation. Age The fauna is inevitably compared to that of the Burgess Shale, although it is probably ten to fifteen million years older – vs. ) – and more closely contemporaneous with the fauna of the Maotianshan shales from Chengjiang, which are dated to . Pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthropod
Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metamerism (biology), metameric) Segmentation (biology), 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 Organ (anatomy), organs. Like their exteriors, the internal organs of arthropods are generally built of repeated segments. They have ladder-like nervous systems, with paired Anatomical terms of location#Dorsal and ventral, ventral Ventral nerve cord, nerve cord ... [...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] |
Kerygmachela
''Kerygmachela kierkegaardi'' is a Kerygmachelidae, kerygmachelid Lobopodia#Gilled lobopodians, gilled lobopodian from the Cambrian Stage 3 aged Sirius Passet Lagerstätte in northern Greenland. Its anatomy strongly suggests that it, along with its relative ''Pambdelurion whittingtoni'', was a close relative of radiodont (''Anomalocaris'' and relatives) and euarthropods. The Generic name (biology), generic name "''Kerygmachela''" derives from the Greek language, Greek words ''Kerygma'' (proclamation) and ''Chela'' (claw), in reference to the flamboyant frontal appendages. The Specific name (zoology), specific name, "''kierkegaardi''" honors Denmark, Danish philosopher Søren Kierkegaard. Morphology The head of ''Kerygmachela'' possesses a pair of well-developed frontal appendages which correspond to those of other Dinocaridida, dinocaridids and Lobopodia#Siberion and similar taxa, siberiid lobopodians. Each of them terminates in a series of long spines. A pair of sessile, sli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megadictyon
''Megadictyon'' is a genus of Cambrian lobopodian with similarities to ''Jianshanopodia'' and '' Siberion''. The name of the genus is occasionally mis-spelt as ''Magadictyon''. Description ''Megadictyon'' is a large lobopodian, with a body length (excluding appendages) possibly up to 20 centimeters in total. The head has a pair of robust frontal appendages associated with rows of spines and terminal claws. Located on the underside of the head is a radiodont-like mouthpart formed by multiple layers of plates and tooth-like structures. The trunk is wide and annulated, with a pair of well-developed lobopodous limbs on each body segment. Only 8 segment/limb pairs are countable in the incomplete fossil materials which are lacking the posterior region, so it may have had more (possibly up to 11 to 13) in nature. It also has pairs of digestive glands similar to those of basal arthropod Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
