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Lomankus
''Lomankus'' is an extinct genus of megacheiran (great appendage) arthropod known from the upper Ordovician aged Beecher's Trilobite Bed, within the larger Frankfort shale in the state of New York (state), New York. A single species is known, ''Lomankus edgecombei'', which was described by Parry ''et al''., 2024. It is currently placed within the family Megacheira, Leanchoiliidae, within the larger Leanchoilida order, and represents the youngest known member of the group. Members of this family are characterized by the presence of long flagelliform structures on their frontal appendages, which were most likely used for both sensory and raptorial purposes. ''Lomankus'' is significant, as it represents the youngest known definitive megacheiran in the fossil record, as well as the only definitive member of the order from post-Cambrian strata. Although several other genera of post-Cambrian arthropods, including members of the family Enaliktidae, have been proposed as members of megach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megacheira
Megacheira ("great hands", also historically great appendage arthropods) is an extinct class of predatory arthropods defined by their possession of spined "great appendages". Their taxonomic position is controversial, with studies either considering them stem-group euarthropods, or stem-group chelicerates. The homology of the great appendages to the cephalic appendages of other arthropods is also controversial. Uncontested members of the group were present in marine environments worldwide from the lower Cambrian to the upper Ordovician. Morphology Megacheirans are defined by their possession of uniramous "great appendages", which are their first pair of head appendages. The first one or two proximalmost segments/ podomeres are spineless (it has been argued that the supposed first of the two proximal podomeres is actually an arthrodial membrane), while the remaining 3–4 more distal podomeres each typically bear a single upward pointing spine attached towards the distal en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
