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Euproops
''Euproops'' is an extinct genus of xiphosuran, related to the modern horseshoe crab. It lived during the Carboniferous Period. The ''Treatise on Invertebrate Paleontology'' describes ''Euproopidae'' as "small forms with wedge-shaped cardiac lobe bordered by distinct axial furrows, abdominal shield with annulated axis bearing a high boss on last segment." The same source describes ''Euproops'' as follows. "Prosoma with flat genal spines and carinate opthamalic spines; cardiopthamalic region with or without intercardiopthamalic area; abdomen with raised pleural ridges that cross flattened rim and are prolonged as marginal spines; annulated axis with knob on 1st and 3rd segments and elevated boss or short spine on hindmost segment; telson long." Unusually, ''Euproops'' may have been semiaquatic, due to being found in terrestrial substrates more often than aquatic ones, as well as the genal and ophthalmic spines of ''E. danae'' closely resembling lycopod twigs, alongside ''E. rotund ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xiphosura
Xiphosura (; , in reference to its sword-like telson) is an order of arthropods related to arachnids. They are more commonly known as horseshoe crabs (a name applied more specifically to the only extant family, Horseshoe crab, Limulidae). They first appeared in the Hirnantian (Late Ordovician). Currently, there are only four living species. Xiphosura contains one suborder, Xiphosurida, and several stem-genera. The group has hardly changed in appearance in hundreds of millions of years; the modern horseshoe crabs look almost identical to prehistoric genera and are considered to be living fossils. The most notable difference between ancient and modern forms is that the abdominal segments in present species are fused into a single unit in adults. Xiphosura were historically placed in the class Merostomata, although this term was intended to encompass also the Eurypterida, eurypterids, whence it denoted what is now thought to be an unnatural (paraphyletic) group (although this is a gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
