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This would also render Porifera (the sponge phylum) paraphyletic. Borchiellini et al. (2001) argued that calcareans were more closely related to Eumetazoa (non-sponge animals) than to other sponges. [9] A few studies have also supported a sister group relationship between calcareans and Ctenophora (comb jellies). Many authors have strongly ...
Archaeocyatha (/ ˈ ɑːr k i oʊ s aɪ ə θ ə /, 'ancient cups') is a taxon of extinct, sessile, reef-building [2] marine sponges that lived in warm tropical and subtropical waters during the Cambrian Period.
Stream 2 was composed of black lava, and entered the other side of the Steam Distribution Corridor. Stream 3, also composed of black lavas, flowed to other areas under the reactor. The well-known "Elephant's Foot" structure is composed of two metric tons of black lava, [18] forming a multilayered structure similar to tree bark. It is said to be ...
Scoria differs from pumice, another vesicular volcanic rock, in having larger vesicles and thicker vesicle walls, and hence is denser.The difference is probably the result of lower magma viscosity, allowing rapid volatile diffusion, bubble growth, coalescence, and bursting.
The term sponge derives from the Ancient Greek word σπόγγος spóngos. [9] The scientific name Porifera is a neuter plural of the Modern Latin term porifer, which comes from the roots porus meaning "pore, opening", and -fer meaning "bearing or carrying".
The word lava comes from Italian and is probably derived from the Latin word labes, which means a fall or slide. [2] [3] An early use of the word in connection with extrusion of magma from below the surface is found in a short account of the 1737 eruption of Vesuvius, written by Francesco Serao, who described "a flow of fiery lava" as an analogy to the flow of water and mud down the flanks of ...
The meshing of many spicules serves as the sponge's skeleton and thus it provides structural support and potentially defense against predators. [1] Sponge spicules are made of calcium carbonate or silica. Large spicules visible to the naked eye are referred to as megascleres or macroscleres, while smaller, microscopic ones are termed microscleres.
The Mare Tranquillitatis pit has been associated with a lava tube. Lunar lava tubes are lava tubes on the Moon formed during the eruption of basaltic lava flows. When the surface of a lava flow cools, it hardens and the lava can channel beneath the surface in a tube-shaped passage. Once the flow of lava diminishes, the tube may drain, forming a ...