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Kingdom Animalia. By: Ernesto Marin & Axel Miranda. Porifera. Porifera is a phylum of aquatic invertebrate animals that comprises the sponges Sponges are animals of the phylum Porifera (Pore bearer). Their bodies consist of jelly-like mesohyl sandwiched between two thin layers of cells
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Kingdom Animalia By: Ernesto Marin & Axel Miranda
Porifera • Porifera is a phylum of aquatic invertebrate animals that comprises the sponges • Sponges are animals of the phylum Porifera (Pore bearer). Their bodies consist of jelly-like mesohyl sandwiched between two thin layers of cells • Has no tissues, no symmetry, no body cavity, no circulatory system, no nervous system; Aquatic filter feeders, and specialized cell types
Stromatoporoida • Stromatoporoids are an extinct, sessile, coral-like marine organism of uncertain relationship that built up calcareous masses composed of laminae and pillars, occurring from the Cambrian to the Cretaceous • Stromatoporoids are an order of colonial aquatic invertebrates • These invertebrates were important reef-formers throughout the Paleozoic and the Late Mesozoic • The group was previously thought to be related to the corals and placed in the Phylum Cnidaria • Stromatoporoids are useful markers whose form and occurrence can diagnose the depositional environment of sedimentary strata
Calcarea • Members of the group Calcarea, are the only sponges that posses spicules composed of calcium carbonate • The spicules do not have hollow axial canals • The Calcarea first appears at the base of the Lower Cambrian and has persisted until the present • Greater than 100 fossil genera are known • The calcarean sponges were at their most diverse during the Cretaceous • Now a days, their diversity is greater in the tropics, as is the case with most marine groups • They are found in shallow waters, though at least one species is known from a depth of 4,000 meters
Hexactinellida • The Hexactinellids, or glass sponges, are characterized by siliceous spicules consisting of six rays intersecting at right angles • Hexactinellids are widely viewed as an early branch within the Porifera because there are major differences between extant hexactinellids and other sponges • Much of their tissues are syncitia, extensive regions of multinucleate cytoplasm • Some discrete cell types do exist, including archaeocytes • Hexactinellids do not posses the ability to contract; whereas, other sponges do • They posses a unique system for rapidly conducting electrical impulses across their bodies, thus allowing them to react quickly to external stimuli
Demospongea • Demospongea are by far the most diverse sponge group • Greater than 90% of the 5,000 known living sponge species are demosponges • The vast majority of living demosponges do not posses skeletons that would easily fossilize, thus their fossil diversity, which peaks in the Cretaceous
References • http://www.google.com/#hl=en&safe=off&q=Porifera&tbs=dfn:1&tbo=u&sa=X&ei=2mrOT_KLJoGi2gXB68TVDA&sqi=2&ved=0CGAQkQ4&bav=on.2,or.r_gc.r_pw.r_qf.,cf.osb&fp=7ffac515254ada2f&biw=1920&bih=979 • http://www.google.com/#hl=en&safe=off&sa=X&q=stromatoporoids&tbs=dfn:1&tbo=u&ei=Wm3OT5XjMMGC2AXwg5HcDA&ved=0CEwQkQ4&bav=on.2,or.r_gc.r_pw.r_qf.,cf.osb&fp=7ffac515254ada2f&biw=902&http://www.google.com/#hl=en&safe=off&sa=X&q=stromatoporoids&tbs=dfn:1&tbo=u&ei=Wm3OT5XjMMGC2AXwg5HcDA&ved=0CEwQkQ4&bav=on.2,or.r_gc.r_pw.r_qf.,cf.osb&fp=7ffac515254ada2f&biw=902&bih=951bih=951 • http://www.ucmp.berkeley.edu/porifera/calcarea.html • http://www.ucmp.berkeley.edu/porifera/hexactinellida.html • http://www.ucmp.berkeley.edu/porifera/demospongia.html