Articulata

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Articulata has three meanings in zoology:

• One of two main divisions of the brachiopods having two valves with an articulating hinge (as opposed to the Inarticulata, which have no hinge). It is now thought that articulating hinges developed independently in several lineages of brachiopoda, hence this character is not a good choice for defining groups. See also Treatise on Invertebrate Paleontology which mentions the new classifications.
• A higher taxon of animals with segmented bodies, consisting of Annelida and Panarthropoda under the hypothesis that these groups are descended from a common segmented ancestor. This hypothesis is not well supported by molecular data, which suggests that segmentation evolved independently in the two groups. An alternative, and better supported, hypothesis is that ecdysis (the shedding of outer cuticle) is a primitive character; this places Panarthropoda in the group Ecdysozoa.
• A subclass of crinoids, the only such to survive past the Paleozoic era.