A few scant brachiopod remains are known from the late Proterozoic, but throughout known geologic time they reached their greatest development in the Paleozoic era, more especially in the Devonian period.
During the Mesozoic era they greatly out-numbered the brachiopod bivalves and took on a more distinctly modern aspect, when the oyster tribe and closely related types were prominently developed.
While on this subject, it may be useful to the student to know that a Brachiopod differs from ordinary bivalves, mussels, cockles, etc.
The triangular space under the beak of many brachiopod shells.
A name formerly given to certain Silurian brachiopod shells of the genus Spirifer.
The body of the Brachiopod usually occupies about the posterior half of the space within the shell.
The soft body of the Brachiopod is in all cases protected by a shell composed of two distinct valves; these valves are always, except in cases of malformation, equal-sided, but not equivalved.
The young Brachiopod in all its species is protected by an embryonic shell called the "protegulum," which sometimes persists in the umbones of the adult shells but is more usually worn off.
The water which bears the oxygen for respiration and the minute organisms upon which the Brachiopod feeds is swept into the mantle cavity by the action of the cilia which cover the arms, and the eggs and excreta pass out into the same cavity.
Defn: A brachiopod shell of the genus Orthis, and allied genera, of the family Orthidæ.
The purpose may have been merely to paralyze the brachiopod or pelecypod which was incautious enough to open its shell in proximity to the asaphid.
The latter species appears first in the Staurocephalus beds which underlie the Brachiopod shales, so that in its first appearance it is somewhat the older.
Dalmanites eucentrus, a species found in the Brachiopod shales (Upper Ordovician) of southern Sweden.
Genera which are polymorphic in one country seem to be, with some few exceptions, polymorphic in other countries, and likewise, judging from Brachiopod shells, at former periods of time.
We may instance Rubus, Rosa, and Hieracium amongst plants, several genera of insects, and several genera of Brachiopod shells.
A name formerly given to certain Silurian brachiopod shells of the genus Spirifer.
Although there is no doubt a striking resemblance between the tentacular disc of a larval Brachiopod and the lophophore of a Polyzoon, which has been pointed out by Lankester, Morse, Brooks, etc.
Reddish limestone, with broken fragments of shells, of the same description of brachiopod as the last.
This interesting brachiopod was found in the limestone by Captain M'Clure, at the Princess Royal Islands, in the Prince of Wales' Strait, between Baring Island and Prince Albert Land.
We may instance Rubus, Rosa, and Hieracium among plants, several genera of insects, and of Brachiopod shells.
Genera which are polymorphic in one country seem to be, with a few exceptions, polymorphic in other countries, and likewise, judging from Brachiopod shells, at former periods of time.
Certain beds of this age have received the name of Lingula Flags, owing this prevalence in them of the curious Brachiopod Lingula so like the species now living in some of the warm seas of the tropics.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "brachiopod" in a variety of sentences. We hope that you will now be able to make sentences using this word.
