Definitions
from The Century Dictionary.
- A class of mollusk-like animals distinguished by the development of two labial (generally called
brachial ) appendages, diverging from either side of the mouth. - In recent years extensive studies of the Brachiopoda have been made: by Joubin on the anatomy of recent species, by Hall and Clarke on the anatomy and taxonomy of fossil forms, and by Beecher on ontogeny and phylogeny. It is now generally conceded that a classification based on the absence or presence of hinge-teeth, which is the foundation of that introduced by Deshayes, Owen, Bronn, and Huxley, or on the perforation or closing of the anus, as in King's scheme, has a value restricted to fully accomplished phylogenetic phases or ontogenetic conditions. In Beecher's classification, variation in the nature of the pedicle-opening is assumed as the basis of ordinal divisions, and the stages of shell-growth and its accessory developments of those of minor value.
- This classification establishes the following orders: Alremata, in which the valves are unhinged and the pedicle emerges freely between them. These are subcircular or elongate shells in which growth takes place freely in all directions except posteriorly. Obolus and Lingula are typical genera.
- Neotremata, in which the valves are also hingeless, cone-shaped, with the pedicle restricted to the ventral valve and the pedicle-aperture modified by a deltidium or listrium. These are circular, often largely calcareous shells (Acrotreta, Orbiculoidea, Discina). Crania and its allies have lost the pedicle by atrophy and are either attached by cementation of their valves or are wholly free.
- Protremata, in which an articulate hinge is developed in progressed forms, the pedicle is restricted to the ventral valve, the deltidium originates on the dorsal side of the larval body but becomes ankylosed to the ventral shell and modifies the pedicle-passage, and the brachia are unsupported by calcareous processes. (Strophomena, Thecidium, Productus, Orthis, Pentamerus.)
- Telotremata, in which the pedicle-passage is shared by both valves in early growth, but is confined to the ventral valve at maturity and modified by deltidial plates which are morphologically distinct from the deltidium and have a later origin in ontogeny. The valves are hinged, the brachia supported by calcareous crura, loops, and spirals. (Rhynchonella, Terebratula, Spirifer, Atrypa.) With the increased knowledge of the structure, distribution, and vertical range of the extinct brachiopods, the number of genera has been augmented to about 400, living and extinct, represented by some thousands of species, 2000 species being recognized in the Paleozoic rocks of North America alone, while about 150 species are now living.
from the GNU version of the Collaborative International Dictionary of English.
- noun (Zoöl.) A class of Molluscoidea having a symmetrical bivalve shell, often attached by a fleshy peduncle.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- proper noun A taxonomic
phylum within thesuperphylum Protostomia — thebrachiopods .
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- noun marine invertebrates that resemble mollusks
Etymologies
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Examples
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Polycoa; those creatures which fabricate the lamp-shells, and are called Brachiopoda; the pearly Nautilus, and all animals allied to it; and all the forms of sea-urchins and star-fishes.
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Emig, ‘Proof that Lingula (Brachiopoda) is not a living-fossil, and emended diagnoses of the Family Lingulidae’, Carnets de Géologie, letter 2003/01 (2003).
THE GREATEST SHOW ON EARTH RICHARD DAWKINS 2009
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Emig, ‘Proof that Lingula (Brachiopoda) is not a living-fossil, and emended diagnoses of the Family Lingulidae’, Carnets de Géologie, letter 2003/01 (2003).
THE GREATEST SHOW ON EARTH RICHARD DAWKINS 2009
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Of the phyla you haven't seen alive, I have seen: Chaetognatha, Nematomorpha, Nemertea, Sipuncula, Echiura which is really a subgroup of Annelida, Phoronida and Brachiopoda.
So many phyla so little time AYDIN 2008
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{7 Brachiopoda {15-20 Brachiopoda} Crustacea} 2 Clay Slate System \ 1st month, typically,
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Kowalevsky, in 1871, showed that the body-cavity of Sagitta was formed by a division of the archenteron into three parallel cavities, and in 1874 demonstrated the same fact for the Brachiopoda.
Form and Function A Contribution to the History of Animal Morphology
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Finding that I wished to devote myself to geology, he set me to work on the Brachiopoda as the best group of fossils to serve as data in determining the Palaeozoic horizons.
Louis Agassiz as a Teacher; illustrative extracts on his method of instruction Lane Cooper
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Finding that I wished to devote myself to geology, he set me to work on the Brachiopoda as the best group of fossils to serve as data in determining the Palaeozoic horizons.
Louis Agassiz as a Teacher Cooper, Lane, 1875-1959 1917
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Such are the corals; those corallines which are called Polycoa; those creatures which fabricate the lamp-shells, and are called Brachiopoda; the pearly Nautilus, and all animals allied to it; and all the forms of sea-urchins and star-fishes.
Autobiography and Selected Essays Huxley, Thomas Henry, 1825-1895 1909
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"Contributions to the Anatomy of the Brachiopoda" "Proceedings of the Royal Society" 7 (1854-55) 106-117; 241, 242.
The Life and Letters of Thomas Henry Huxley Huxley, Leonard 1900
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