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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.
The stalk (or pedicle) is a long white extension of the body, that emerges at the apex from between the valves, and not, as in articulate brachiopods, from a special opening in the dorsal valve. At the rear end, that is deepest in the sea bed, the skin (or epithelium ) secretes a glue-like mucus that binds to the substrate's particles, thus ...
Linguliformea. Linguliformea is a subphylum of inarticulate brachiopods. [1] These were the earliest of brachiopods, ranging from the Cambrian into the Holocene. They rapidly diversified during the Cambrian into the Ordovician, but most families became extinct by the end of the Devonian. The articulation in these brachiopods is lacking.
Atrypa is a genus of brachiopod with round to short egg-shaped shells covered with many fine radial ridges (or costae). Growth lines form perpendicular to the costae and are spaced approximately 2 to 3 times further apart than the costae.. The pedunculate valve is slightly convex, but oftentimes levels out or becomes slightly concave toward the ...
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]
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.
Rhynchonelliformea. Rhynchonelliformea is a major subphylum and clade of brachiopods. It is roughly equivalent to the former class Articulata, which was used previously in brachiopod taxonomy up until the 1990s. These so-called articulated brachiopods have many anatomical differences relative to "inarticulate" brachiopods of the subphyla ...
Terebratalia is a genus of brachiopods belonging to the family Terebrataliidae. [1] Terebratalia** is a genus of brachiopods, marine animals with hard "shells" on their upper and lower surfaces, similar to bivalve mollusks. These organisms are part of the phylum Brachiopoda, which are often referred to as "lamp shells" due to their resemblance ...