Brachiopod
Brachiopods (Brachiopoda) are one of the major animal phyla. They are sessile, two-shelled, marine animals that somewhat resemble pelecypod mollusks (i.e. "clams") externally but are quite different internally. Unlike bivalves, which have a left shell and a right shell, brachiopods are always bilaterally symmetric, although the top and bottom shells usually differ in shape. The shells may be either phosphatic or calcaerous. Some fossil forms had elaborate spines.Brachiopods come in two varieties. Inarticulate brachiopods are held together entirely by musculature whereas articulate brachiopods have hinges. Brachiopods are always marine and are found either attached to hard substrates by a structure called a pedicle or resting on muddy bottoms. Brachiopods are filter feeders with a distinctive feeding organ called a lophophore, found among the various different groups of lophophorates.
The earliest known brachiopods are found in the late Neoproterozoic. The first brachiopods were inarticulate, but articulate brachiopods appeared soon thereafter, in the Lower Cambrian. Brachiopods are extremely common fossils throughout the Paleozoic. They were largely replaced by mollusks in the Mesozoic. Brachiopods -- both articulate and inarticulate -- are still present in modern oceans.
The inarticulate brachiopod genus Lingula has the distinction of being the oldest more or less unchanged animal known. The oldest Lingula occur in the very early Cambrian and are roughly 550 million years old. The origin of brachiopods is unknown. A possible ancestor is a sort of ancient "armored slug" called a halkeriid[?] that has recently been found to have had small brachiopod-like shields on its head and tail.
fear, will be homeless in her old age. The mortgage shall be
Jan. His creditors, Jan--you have overlooked just one. I am/am.html">am sorry
you, my young friend. You will have to begin life over again.
word, your ship.html">ship is mine. I wish you joy of your bride, my young
price for her."
It was Nicholas Snyders' grin that maddened Jan. He sought for
it, and by chance his hand lighted on the pedlar's silver flask. In
grin had died away.
"Sit down," commanded Nicholas Snyders. "Let us talk further." And
obedience.
"You wonder, Jan, why I seek always anger and hatred. I wonder at
men! Listen, Jan; I am in a whimsical mood. Such things cannot be,
soul.html">soul.html">soul.html">soul, Jan, sell me your soul, that I, too, may taste this love and
little while, and I will give you all you desire."
The old man.html">man.html">man seized his pen and wrote.
"see.html">See, Jan, the ship is yours beyond mishap; the mill goes free; your
drink to me, willing the while that your soul may go from you and
for a little while."
With feverish hands the old man had drawn the stopper from the
inclination was to laugh, but the old man's eagerness was almost
paper he had signed.html">signed. A true man does not jest with his soul, but the
Jan, replacing his empty glass upon the table. And the two stood
though a breath had blown them, first one and then the other.
"I must be getting home," came the voice of Jan from the darkness.
not add that he had meant to ask that same question of Jan. He thrust
shadows crept back into their corners.
"You will not stop and see Christina?" asked Nicholas.
"Not to-night," answered Jan.
"The paper that I signed," Nicholas reminded him--"you have it?"
.
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