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Wednesday, July 29, 2009

Pennsylvania "Trilobite" ?

Pennsylvania actually should be added to the list of states - Kansas, New Jersey and Virginia - which have not designated an official State gem, rock, stone or mineral. However some charts show Trilobite and leave it at that. However, the fossil from the Phacops rana Trilobite was named by the State Legislature as the State Fossil in 1988.
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Phacops rana (Trilobite) is a fossil organism known as a Trilobite (pronounced “tri-lobe-ite”). Trilobites are an extinct category of jointed-legged animals related to crabs, lobsters, shrimp, spiders, insects, and so on. This group of creatures, called arthropods, are among the most complex of all the animals without backbones and trilobites are no exception. They had well-developed nervous systems and large antennae. Trilobites had many appendages for swimming, walking, or feeding. Although these appendages are relatively rare in most groups of trilobite fossils. Phacops is one of four genera for which they are fairly well known and studied. Trilobites also had a hard outer skeleton composed of chitin, a complex organic protein, and the mineral apatite.
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Trilobites are a common fossil in many of the early to middle Paleozoic rocks of central Pennsylvania, i.e., rocks that are between 570 and 365 million years old. Complete fossil specimens are rare because the animals were composed of rigid outer skeletal segments joined by flexible organic connections that decayed on the death of the animal. An interest in trilobites is not restricted to scientists and geological dilettantes. They are prized by lapidarist and jewelry and curio collectors. This interest is a long-standing one. Trilobites were found on necklaces belonging to the prehistoric inhabitants of 15,000 year old rock shelters of Europe. The Ute Indians of the western United States fashioned trilobites into amulets. The Ute name for these fossils was, “timpe khanitza pachavee” which means “little water but like stone house in.”
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The best place to hunt for Trilobite is at Swatara State Park. Fossil beds are exposed along the Old State Road and provides a variety of Devonian age (375 million years ago) marine fossils. Swatara State Park is in Lebanon and Schuylkill counties, 14 miles north of Lebanon and three miles west of Pine Grove. The park is easily reached from I-81.
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Picture of Pennsylvania Trilobite from fossilman
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