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Labechiida
Labechiida is an extinct Order (biology), order of Stromatoporoidea, stromatoporoid sponges. They lived from the Early Ordovician (Tremadocian stage) to the Late Devonian (Famennian stage),'''' though a few putative fossils have been reported from younger sediments. Labechiids were the first order of stromatoporoids to appear and were probably ancestral to all other orders in the main Paleozoic radiation (Stromatoporoidea ''sensu stricto).'' They were most diverse and abundant during the Middle-Late Ordovician and the Famennian, when they were a major group of reef-building sponges. However, they were relatively uncommon through most of the Silurian and Devonian, in contrast to other stromatoporoids. Labechiids can be differentiated from other stromatoporoids by having an internal structure emphasizing cysts (pockets roofed by flat or convex cyst plates) and pillars (solid rods perpendicular to the surface).'''' The pillars may extend all the way to the surface and project out a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stromatoporoidea
Stromatoporoidea is an extinct clade of sea sponges common in the fossil record from the Middle Ordovician to the Late Devonian.Stock, C.W. 2001, Stromatoporoidea, 1926–2000: ''Journal of Paleontology'', v. 75, p. 1079–1089. They can be characterized by their densely layered calcite skeletons lacking Sponge spicule, spicules. Stromatoporoids were among the most abundant and important reef-builders of their time, living close together in flat biostromes or elevated bioherms on soft tropical carbonate platforms. Externally, some species have raised bumps (mamelons) and star-shaped crevices (astrorhizae), which together help vent exhalant water away from the living surface. Internally, stromatoporoids have a mesh-like skeletal system combining extensive horizontal layers (laminae), vertical rods (pillars), and boxy spaces (galleries), along with other features. The most common growth forms range from laminar (flattened) to domical (dome-shaped). Spheroidal, finger-like, or tree-l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
