The tabulate corals, forming the order Tabulata, are an extinct form of coral. Their distinguishing feature is their well-developed horizontal internal partitions (tabulae) but reduced or absent vertical internal partitions (septae). They are almost always colonial, forming colonies of hexagonal cells that similar to a honeycomb. Scientific classification or biological classification refers to how biologists group and categorize extinct and living species of organisms. ... In biology and ecology, extinction is the ceasing of existence of a species or group of species. ... Subclasses Alcyonaria Zoantharia See text for orders. ... Medieval illustration of Tabula players (13. ... For the abbreviation SEPTA, see SEPTA. A septum, in general, is a wall separating two cavities or two spaces containing a less dense material. ... In politics and in history, a colony is a territory under the immediate political control of a geographically-distant state. ... A regular hexagon In geometry, a hexagon is a polygon with six edges and six vertices. ... A cell is a single unit or compartment, enclosed by a border or wall. ... Honeycomb on a Langstroth frame A honeycomb is a mass of hexagonal wax cells built by honeybees in their nests to contain their larvae and stores of honey and pollen. ...

Their corallites are usually smaller than those of rugose corals. The skeletons of tabulate corals consist of calcite. Suborders Columnariina† Cystiphyllina† Streptelasmatina† The Rugosa, also called the Tetracoralla, are an extinct order of coral that were abundant in Middle Ordovician to Late Permian seas. ... Skeleton of a Blue Whale In biology, the skeleton or skeletal system is the biological system providing physical support in living organisms. ... SAM WAS HERE!!!!!!!!!! Doubly refracting Calcite from Iceberg claim, Dixon, New Mexico. ...

Like rugose corals, they lived entirely during the Paleozoic, and became extinct in the Permian-Triassic extinction event. The Paleozoic Era is a major division of the geologic timescale, one of four geologic eras. ... The Permian-Triassic extinction event, labeled End P here, is the most significant extinction event in this plot for marine fossiliferous genera. ...