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Megacheira
Megacheira ("great hands") is an extinct class of predatory arthropods that possessed a pair of great appendages, hence the class name as well as the common name "great appendage arthropods". Their taxonomic position is controversial, with studies either considering them stem-group euarthropods, or stem-group chelicerates. Most of them were found in marine environments throughout the world from the lower to middle Cambrian. Megacheirans were important components of several faunas, including the Burgess, Wheeler and Maotianshan Shales Lagerstatten. Homology of great appendages The homology between megacheiran great appendages and cephalic appendages of other arthropods had been discussed for decades. There is controversy over whether they are homologous to both dinocaridid ( radiodonts and gilled lobopodians) frontal appendages, the frontalmost appendages of '' Isoxys'' and chelicerates' chelicerae. Based on neuroanatomical evidences, many studies support their homolog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Appendage
Great appendages are claw-like appendages which attach to the heads of the "great appendage arthropods", a name usually refers to Megacheira, a class of extinct arthropod characterized by a pair of "short-great appendages" bearing in front of the animal's head. In general, megacheiran's great appendage have 6 segments, with the two proximal segments forming a peduncle and the four finger-like distal segments forming a claw, both connected by an elbow joint. Great appendages have been interpreted as raptorial limbs involved in predation, with those of some genera such as ''Yohoia'' being structurally comparable to the raptorial maxillipeds of mantis shrimp. The great appendages of leanchoilid megacheirans such as ''Leanchoilia'' and ''Yawunik'' have elongated flagella, suggesting a sensory role alongside predatory function. Radiodonta, Radiodont's frontal appendages have controversial relationships to those of the megacheirans. They have been suggested to be Homology (biology), ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megacheira Reconstructions
Megacheira ("great hands") is an extinct class of predatory arthropods that possessed a pair of great appendages, hence the class name as well as the common name "great appendage arthropods". Their taxonomic position is controversial, with studies either considering them stem-group euarthropods, or stem-group chelicerates. Most of them were found in marine environments throughout the world from the lower to middle Cambrian. Megacheirans were important components of several faunas, including the Burgess, Wheeler and Maotianshan Shales Lagerstatten. Homology of great appendages The homology between megacheiran great appendages and cephalic appendages of other arthropods had been discussed for decades. There is controversy over whether they are homologous to both dinocaridid (radiodonts and gilled lobopodians) frontal appendages, the frontalmost appendages of ''Isoxys'' and chelicerates' chelicerae. Based on neuroanatomical evidences, many studies support their homology to c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kootenichelidae
Megacheira ("great hands") is an extinct class of predatory arthropods that possessed a pair of great appendages, hence the class name as well as the common name "great appendage arthropods". Their taxonomic position is controversial, with studies either considering them stem-group euarthropods, or stem-group chelicerates. Most of them were found in marine environments throughout the world from the lower to middle Cambrian. Megacheirans were important components of several faunas, including the Burgess, Wheeler and Maotianshan Shales Lagerstatten. Homology of great appendages The homology between megacheiran great appendages and cephalic appendages of other arthropods had been discussed for decades. There is controversy over whether they are homologous to both dinocaridid (radiodonts and gilled lobopodians) frontal appendages, the frontalmost appendages of ''Isoxys'' and chelicerates' chelicerae. Based on neuroanatomical evidences, many studies support their homology to c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leanchoiliidae
Megacheira ("great hands") is an extinct class of predatory arthropods that possessed a pair of great appendages, hence the class name as well as the common name "great appendage arthropods". Their taxonomic position is controversial, with studies either considering them stem-group euarthropods, or stem-group chelicerates. Most of them were found in marine environments throughout the world from the lower to middle Cambrian. Megacheirans were important components of several faunas, including the Burgess, Wheeler and Maotianshan Shales Lagerstatten. Homology of great appendages The homology between megacheiran great appendages and cephalic appendages of other arthropods had been discussed for decades. There is controversy over whether they are homologous to both dinocaridid (radiodonts and gilled lobopodians) frontal appendages, the frontalmost appendages of ''Isoxys'' and chelicerates' chelicerae. Based on neuroanatomical evidences, many studies support their homology to c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leanchoiliida
Megacheira ("great hands") is an extinct class of predatory arthropods that possessed a pair of great appendages, hence the class name as well as the common name "great appendage arthropods". Their taxonomic position is controversial, with studies either considering them stem-group euarthropods, or stem-group chelicerates. Most of them were found in marine environments throughout the world from the lower to middle Cambrian. Megacheirans were important components of several faunas, including the Burgess, Wheeler and Maotianshan Shales Lagerstatten. Homology of great appendages The homology between megacheiran great appendages and cephalic appendages of other arthropods had been discussed for decades. There is controversy over whether they are homologous to both dinocaridid (radiodonts and gilled lobopodians) frontal appendages, the frontalmost appendages of ''Isoxys'' and chelicerates' chelicerae. Based on neuroanatomical evidences, many studies support their homology to c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jianfengiidae
Megacheira ("great hands") is an extinct class of predatory arthropods that possessed a pair of great appendages, hence the class name as well as the common name "great appendage arthropods". Their taxonomic position is controversial, with studies either considering them stem-group euarthropods, or stem-group chelicerates. Most of them were found in marine environments throughout the world from the lower to middle Cambrian. Megacheirans were important components of several faunas, including the Burgess, Wheeler and Maotianshan Shales Lagerstatten. Homology of great appendages The homology between megacheiran great appendages and cephalic appendages of other arthropods had been discussed for decades. There is controversy over whether they are homologous to both dinocaridid (radiodonts and gilled lobopodians) frontal appendages, the frontalmost appendages of ''Isoxys'' and chelicerates' chelicerae. Based on neuroanatomical evidences, many studies support their homology to c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cheiromorpha
Megacheira ("great hands") is an extinct class of predatory arthropods that possessed a pair of great appendages, hence the class name as well as the common name "great appendage arthropods". Their taxonomic position is controversial, with studies either considering them stem-group euarthropods, or stem-group chelicerates. Most of them were found in marine environments throughout the world from the lower to middle Cambrian. Megacheirans were important components of several faunas, including the Burgess, Wheeler and Maotianshan Shales Lagerstatten. Homology of great appendages The homology between megacheiran great appendages and cephalic appendages of other arthropods had been discussed for decades. There is controversy over whether they are homologous to both dinocaridid (radiodonts and gilled lobopodians) frontal appendages, the frontalmost appendages of ''Isoxys'' and chelicerates' chelicerae. Based on neuroanatomical evidences, many studies support their homology to c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fortiforceps
''Fortiforceps'' is an extinct genus of Cambrian megacheiran arthropod known from the Chengjiang biota of Yunnan, China. It was originally described by Hou and Bergström in 1997,X. Hou and J. Bergström. 1997Arthropods of the Lower Cambrian Chengjiang fauna, southwest China Fossils & Strata 45:1-116 and redescribed in 2020. It was relatively small, at or less in length. The head has a large pair of stalked eyes, a pair of frontal projections, as well as a pair of great appendages, like other megacheirans, along with two other cephalic appendages. The trunk has either 20 or 22 segments, depending on the specimen. These segments have pronounced blade-like spines on their upper-outer edge. Each of the trunk segments (aside from the last, typically 20th segment) are associated with pairs of biramous The arthropod leg is a form of jointed appendage of arthropods, usually used for walking. Many of the terms used for arthropod leg segments (called podomeres) are of Latin origin, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enalikter
''Enalikter'' ("scourger of the sea") is an extinct arthropod described from the middle Silurian Herefordshire Lagerstätte at the England–Wales border in UK. This genus is known from only one species, ''E. aphson''. ''Enalikter'' is described as late-living example of Megacheira, "great-appendage arthropod". It was once considered as an annelid by other researchers, however subsequent studies denied this. Its interpretation as megacheiran arthropod is questioned in later study. Morphology ''Enalikter'' is small arthropod with length just around long. Head shield is subrectangular and lacked eyes. Median, unpaired antenna and three pairs of appendages can be seen on head, and a first appendage had three tapering flagella. Twelve trunk segments lack tergites, and is flexible to bend at least 90 degrees. Trunk appendages are biramous. Egg-like shaped telson had two pairs of blade-like processes. Classification ''Enalikter'' is probably related to '' Bundenbachiellus'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parapeytoia
''Parapeytoia'' was a prehistoric arthropod that lived over 530 million years ago (Cambrian Stage 3) in the Maotianshan shales of prehistoric China. It was interpreted as an anomalocaridid (radiodont) with legs, but later studies reveal it was a megacheiran, a group of arthropods which are no longer thought to be closely related to the radiodonts. ''Parapeytoia'' is known from a few incomplete fossil materials with part of its ventral structures preserved. The frontmost appendages were a pair of great appendages that had a peduncle and 4 spines on each of them, a characteristic feature shared by other megacheirans such as ''Yohoia'' and '' Fortiforceps''. Behind the great appendages were 2 or 3 pairs of short appendages, and numerous pairs of well-developed biramous appendages, each formed by a basipod with spiny gnathobase, lobe-like exopod and leg-like endopod with 8 segments. A narrow sternite associated between each of those appendages. Some features originally interpret ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sklerolibyon
''Sklerolibyon'' is an extinct genus of megacheiran arthropod, known from the Cambrian aged Chengjiang biota of Yunnan, China. It is a member of the family Jianfengiidae, alongside '' Jianfengia'' and ''Fortiforceps,'' and possibly also ''Parapeytoia''. Specimens are around in length. The body is greatly elongated, and head shield is heavily sclerotised, with a pair of spines radiating outward from the sides. Alongside the pair of great appendages, there are a pair of stalked eyes and at least two other pairs of limbs on the cephalon. The trunk has 34 segments with corresponding biramous appendages, with typically megacheiran paddle-shaped exopods. The tail is unknown but like ''Jianfengia'' probably ended in a telson The telson () is the posterior-most division of the body of an arthropod. Depending on the definition, the telson is either considered to be the final segment of the arthropod body, or an additional division that is not a true segment on accou ... spine. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jianfengia
''Jianfengia'' is an extinct genus of Middle Cambrian (Atdabanian) megacheiran arthropod found in the Maotianshan Shale Lagerstätte of China. It contains the single species ''Jianfengia multisegmentalis''.''Jianfengia'' in the The body is extremely elongated, though the animal itself was relatively small at less than in length. The head has a pair of stalked eyes, a / labrum< ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
