Unpolished L i tuites sp.
A nice fossil specimen of
unpolished L i tuites sp. (family Lituitidae, order Tarphycerida) -sea animal from China. It is
dated to middle Ordovician period(460 million years).
Specimen is from the mountainous area
of western Hunan province of China (central region).
It measures 4.2x1.4cm (1.65x0.55inch).
Matrix size is 4.2x1.4x1.3 cm.
Weight:
12.4 gram
Shipping cost:
Free shipping cost.
Goods will be sent by airmail from Hong
Kong and it may take 12 -18 working days to arrive.
***
L i tuites sp.
Phylum:
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Mollusca
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Class:
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Cephalopoda
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Subclass:
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Nautiloidea
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Order:
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Tarphycerida
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Family:
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Lituitidae
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Genus:
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Lituites
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Lituites , genus of extinct cephalopods (primitive animals
related to the modern pearly nautilus) found as fossils in marine rocks of the Ordovician Period
(the Ordovician Period lasted from about 488 million to 444 million years ago).
The distinctive shell of Lituites is composed of serially arranged
chambers. The shell begins with a tightly coiled portion that gradually
straightens out after a few whorls; the anterior portion of the shell, the
largest part, is straight in form and expands toward the front. The sutures
between the chambers appear as simple lines around the shell.
Fossils have been found
in USA ( New York ) , Argentina , Norway , Sweden , Estonia , and China
(Hunan) .
Lituites produced a shell with a planospirally coiled
juvenile portion at the apex, reflective of its tarphycerid ancestry, followed
by a long, moderately expanding, generally straight, orthoconic adult section
with a subdorsal siphuncle connecting the chambers. The adult body chamber may
equal or exceed the length of the chambered part of the orthoconic section. The
mature aperture has a pair of pronounced ventrolateral lappets and a similar
but shorter pair of dorsolateral lappets.
Lituites gives its name to the term
"lituiticone" which refers to a shell that is coiled in the early
growth stage and later becomes uncoiled.
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