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The Rock Professor has provided you with a mineral
information card. Print on stock paper, and cut out to
enhance your rock and mineral products.
To print: with your cursor, highlight the entire card below,
right click and select print, then click on "selection"
and print.
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THE ROCK PROFESSOR
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AMMONITES
AMMONITE–AN EXTINCT SUBCLASS OF THE CEPHALOPOD CLASS OF THE PHYLUM MOLLUSCA (Mollusks). Present-day cephalopods include the octopus, squid and nautilus, which is the closest in appearance to the ammonite. Ammonites ranged in time from approximately 400 million years(Devonian) until about 65 million years.(late Cretaceous). Their chambered shells are found today, while their soft bodies, which occupied the largest and outermost chambers, are gone. The septa, plates which divide the chambers, are highly visible in cut fossilized ammonite specimens.
Ammonites had a tube called a siphuncle, which carried water from outside the shell to the chambers, and was used to propel the ammonite as well as to change its depth in the water. Cephalopods, such as the ammonite, were swimming mollusks, rather than attached (pelecypods) or bottoms dwelling(gastropods) mollusks.
The ammonites showed an increasingly complex pattern of sutures on their shells as time went by. Sutures are the intersections of the septa and the outer shells.
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Ammonite shells: originally composed of aragonite; after fossilization, the shell becomes calcite.
Ammolite: some of the original shells retained their mother of pearl nacre over the centuries, which during fossilization, was chemically transformed into an iridescent material called ammolite (aragonite with varying mineral impurities).
Localities: include Russia, England, Morocco, U.S., Madagascar.
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Drawing of an
ancient living
ammonite
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Sculptured Ammonite on Fossil Matrix Base,
$96.00
FSL 235
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Ammonite, cut and polished halves,
$72.00
FSL 236
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Ammonite Pair
$62.00
FSL 248
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Ammonite Pair,
$70.00
FSL 249 |
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Ammonite,
$225.00
FSL 161
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Ammonite Gonaitite,
$145.00
FSL 361
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Ammonite Orthoceras Sculpture,
$40.00
FSL 566
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Ammonite Orthoceras Sculpture,
$36.00
FSL 565
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Ammonite Orthoceras Sculpture,
$38.00
FSL 567
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Ammonite Fossil,
FSL 729
$40.00 |
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Ammonite Fossil,
FSL 730
$19.55 |
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Ammonite Pair
in Bamboo Box
FSL 859
$9.95
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Ammonite Pairs
Package of 5
FSL 956
$20.00
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