Brachiopoda Sentence Examples
They exist in the Brachiopoda (which are probably not unrelated to the Chaetopoda), but otherwise are absolutely distinctive of the Chaetopods.
In a later scheme based on our increased knowledge of fossil forms, the Brachiopoda are divided into four primary groups (orders).
The number and position of the muscles differ materially in the two great divisions into which the Brachiopoda have been grouped, and to some extent also in the different genera of which each division is composed.
Unfortunately almost every anatomist who has written on the muscles of the Brachiopoda has proposed different names for each muscle, and the confusion thence arising is much to be regretted.
Such is the general arrangement of the shell muscles in the division composing the articulated Brachiopoda, making allowance for certain unimportant modifications observable in the animals composing the different families and genera thereof.Advertisement
Beecher's division of the Brachiopoda into four orders is based largely on the character of the aperture through which the stalk or pedicle leaves the shell.
Little light has been thrown on the affinities of the Brachiopoda by recent research, though speculation has not been wanting.
A full bibliography of Brachiopoda (recent and fossil) is to be found in Davidson's Monograph of British Fossil Brachiopods, Pal.
Hatschek (1888) treated the Entoprocta as a division of his group Scolecida, characterized by the possession of a primary body-cavity and of protonephridia; while he placed the Ectoprocta, with the Phoronida and Brachiopoda, in a distinct group, the Tentaculata.
In the animal kingdom it occurs as both calcite and aragonite in the tests of the foraminifera, echinoderms, brachiopoda, and mollusca; also in the skeletons of sponges and corals.Advertisement
From a study of remains of the mollusca, brachiopoda and other marine organisms they will determine the shallow water (littoral) and deep water (abyssal) regions of the surrounding oceans, and the clear or muddy, salt, brackish or fresh character of its inland and marginal seas; and even the physical conditions of the open sea at the time will be ascertained.
The last class which has been removed from the Cuvierian Mollusca is that of the Lamp-shells or Brachiopoda.
Henri Milne-Edwards in 1844 demonstrated the affinities of the Polyzoa with the Molluscan class Brachiopoda, and proposed to associate the three classes Brachiopoda, Polyzoa and Tunicata in a large group " Molluscoidea," co-ordinate with the remaining classes of Cuvier's Mollusca, which formed a group retaining the name Mollusca.
By subsequent writers the Polyzoa have in some cases been kept apart from the Mollusca and classed with the " Vermes "; whilst by others they have, together with the Brachiopoda, been regarded.as true Mollusca.
Increase of knowledge has now, however, established the conclusion that the agreement of structure supposed to obtain between Polyzoa and true Mollusca is delusive; and accordingly they, together with the Brachiopoda, were removed from the Molluscan phylum by Lankester in his article in the 9th edition of this work (on the which present article is based).Advertisement
The most that can be said is that the Chaetognaths begin life with three segments, a feature they share with such widelydiffering groups as the Brachiopoda, the Echinoderma and the Enteropneusta, and probably Vertebrata generally.
The conception of the Dipleurula derives its chief weight from the fact that it is comparable to the early larval forms of other primitive coelomate animals, such as Balanoglossus, Phoronis, Chaetognatha, Brachiopoda and Bryozoa.
The development of Phoronis was supposed by Caldwell (2) to furnish the explanation of the relations of the surfaces in Brachiopoda, Polyzoa and perhaps the Sipunculoid Gephyrea, in which the ontogenetic evidence is less clear.