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Brachiopod. Brachiopods (/ ˈbrækioʊˌpɒd /), phylum Brachiopoda, are a phylum of trochozoan animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, while the front can be opened for feeding or closed for protection.
Evolution of brachiopods. The origin of the brachiopods is uncertain; they either arose from reduction of a multi-plated tubular organism, or from the folding of a slug-like organism with a protective shell on either end. Since their Cambrian origin, the phylum rose to a Palaeozoic dominance, but dwindled during the Mesozoic.
The evolution of fish began about 530 million years ago during the Cambrian explosion. It was during this time that the early chordates developed the skull and the vertebral column, leading to the first craniates and vertebrates. The first fish lineages belong to the Agnatha, or jawless fish. Early examples include Haikouichthys.
See text. Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) [6] are a phylum of simple, aquatic invertebrate animals, nearly all living in sedentary colonies. Typically about 0.5 millimetres (⁄64 in) long, they have a special feeding structure called a lophophore, a "crown" of tentacles used for filter feeding.
L. waikatoensis Pen, 1930. Synonyms. Ligula, Ligularius, Lingularius, Pharetra. Lingula is a genus of brachiopods within the class Lingulata. Lingula or forms very close in appearance have existed possibly since the Cambrian. Like its relatives, it has two unadorned organo-phosphatic valves and a long fleshy stalk.
A Devonian spiriferid brachiopod from Ohio which served as a host substrate for a colony of hederellids. Spiriferida is an order of extinct articulate brachiopod fossils which are known for their long hinge-line, which is often the widest part of the shell. In some genera (e.g. Mucrospirifer) it is greatly elongated, giving them a wing-like ...
List of living brachiopod species. The following is a taxonomy of extant (living) Brachiopoda by Emig, Bitner & Álvarez (2019). There are over 400 living species and over 120 living genera of brachiopods classified within 3 classes and 5 orders, listed below. Extinct groups are not listed. [1]
An Ordovician strophomenid with encrusting inarticulate brachiopods (the craniid Philhedra) and a bryozoan. Strophomenida is an extinct order of articulate brachiopods which lived from the lower Ordovician period to the mid Carboniferous period. [2] Strophomenida is part of the extinct class Strophomenata, and was the largest known order of ...