Claffification:
Phylum Arthropoda
Class: Trilobita
Order: Phacopida
Family: Phacopidae
Location: Morocco
SPECIAL PRICE $6.50 - each
|
|
|
F1180 - Silurian to Devonian periods..... 350
million to 435 million years old. The Phacops Trilobites are found
world-wide. These are complete specimens with little or no matrix and
most of the trilobites are curled into a ball-like position. You can
actually see the facets on the large eyes on most specimens.
"Over 17,000 species of trilobites have been found and identified to
date. And new species of trilobites are unearthed and described each
year. Trilobites are truly remarkable, hard-shelled, segmented
creatures that existed over 300 million years ago in the earth's
ancient seas. The earliest trilobite known from the fossil record
dates back some 543 million years and the last trilobites became
extinct about 251 million years ago. Specimens of trilobite have
been found as small as one-eighth of an inch long to over 28"
long. All 17,000 plus trilobites can be classed in nine orders, over
150 families, and about 5,000 genera.
The trilobites were among the earth's ARTHROPODS. Trilobites had an
outer segmented shell and were there exoskeleton, wearing their
skeleton on the outside it's body, like todays lobster.
All trilobite fossils have a similar body plan, being made up of
three main body parts: A cephalon, or head, a segmented thorax, or
main body section, and pygidium, or tail section. Therefore the
name, trilobite, meaning three-sectioned.
Trilobites hatched from eggs as tiny larva. As the trilobite grew it
shed its exoskeleton, or outer shell, in a process of molting. The
trilobite would have molted a number of times during it life
span. This accounts for the large number of trilobite fossils, as a
single trilobite would have left a number of shed exoskeletons
behind. This also explains why it is that many trilobite fossils
have what appears broken, or separated, skeleton segments.
Some species of trilobite lived in shallow seas and had large eyes
while other trilobite species were blind, probably living too deep in
the sea for light to reach them. The trilobite also had antennae
that perhaps were used for taste and smell.
According to some scientist, the closest extant relatives of the
trilobite may be the horseshoe crabs.
|
