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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.
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.
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 ...
Lingulata shells are composed of a combination of calcium phosphate, protein and chitin. This is unlike most other shelled marine animals, whose shells are made of calcium carbonate. The Lingulata are inarticulate brachiopods, so named for the simplicity of their hinge mechanism. This mechanism lacks teeth and is held together only by a complex ...
The region around what is today Oslo was a hotbed of atrypide rediversification. [30] Brachiopod recovery consisted mainly of the reestablishment of cosmopolitan brachiopod taxa from the Late Ordovician. [31] Progenitor taxa that arose following the mass extinction displayed numerous novel adaptations for resisting environmental stresses. [32]
Mucrospirifer is a genus of extinct brachiopods in the class Rhynchonellata (Articulata) and the order Spiriferida. They are sometimes known as "butterfly shells". [2] Like other brachiopods, they were filter feeders. These fossils occur mainly in Middle Devonian strata [2] and appear to occur around the world, except in Australia and ...
Category. : Brachiopods. Wikimedia Commons has media related to Brachiopoda. Paleontology portal. Brachiopods — a type of shelled invertebrate marine animals group of the Protostome. It first appeared in the Paleozoic Era.
In 2003 Cohen, Holmer and Luter supported the halkieriid-brachiopod relationship, suggesting that brachiopods may have arisen from a halkieriid lineage that developed a shorter body and larger shells, and then folded itself and finally grew a stalk out of what used to be the back. [35]