rings. 9–10 deep and wide pleural furrows have flat or only slightly concave bottoms. The furrows within each pleural rib (or interpleural furrows) are very narrow. The frontal band of each pleural rib is more vaulted and broader than the rear band. The pleural furrows almost reach the margin. The pygidial termination (or mucro) is vaulted and more or less pointed into a spine, which may differ between species. The entire exoskeleton is covered in fine and coarse granules. A specimen of an indeterminate species with preserved soft tissue is known from the Silurian aged Coalbrookdale Formation of England. The antennae are not preserved, though biramous limb pairs are preserved, three are present on the cephalon, 11 on the thorax and at least 3 on the pygidium. The thoracic pairs become smaller posteriorly. The exopods of the limbs bear filamentous structures, which appear to be joined with each other by a membrane. References Dalmanitidae Ordovician trilobites Silurian trilobites Devonian trilobites Trilobites of North America Devonian trilobites of South America Devonian Colombia Fossils of Colombia Late Ordovician first appearances Middle Devonian genus extinctions Fossil taxa described in 1852 Jeffersonville Limestone Paleozoic life of Ontario Floresta Formation Paleozoic life of New Brunswick Paleozoic life of Nova Scotia Paleozoic life of Quebec Taxa named by Joachim Barrande