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Trilobites are a type of extinct marine arthropod probably most closely related to modern Horseshoe crabs. They first appeared in the fossil record in the Early Cambrian some 521 million years ago and went extinct some 252 or more million years ago during the Permian period. Various species of trilobites developed complex eyes, retractable antennae, and even protective spines. Trilobites range in size from a fraction of an inch to over two feet in length. Their exoskeletons were composed of extremely hard calcite and calcium phosphate minerals to protect the soft internal organs, and as a result they are quite well represented in the fossil record and are used as an index fossil. We offer a nice selection of authentic trilobite fossils for sale. Individual shapes and fossils vary but your item will resemble the pictured examples.

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Item # Item Description Price
Diacalymene ouzregui sp. Trilobite - Reddish-brown Trilobite from Morocco - approximately 3" in length. They are actually the molds of the shells of Diacalymene trilobites. Their reddish-brown color is from limonite in the deposit where they are found. The Diacalymene belongs to the same family of trilobites as the Calymene and the Flexicalymene.

Elrathia kingii Trilobite: Trilobites were one of the most abundant forms of life during the Cambrian period. These Middle Cambrian period trilobites from Utah are good examples and show a lot of detail including the characteristic head shield. The large specimens are approximately 1" in length.

Elrathia kingii Trilobite: Medium sized specimens are approximately 3/4" in length. The Elrathia kingii is one of the most common trilobite fossils in the United States.
$ 9.00

Elrathia kingii Trilobite: Small specimens are approximately 1/2" in length. Trilobites lived in marine waters and were some of the first organisms to develop multiple appendages for moving around.
$ 6.00

Elrathia kingii Trilobite: These are the smallest example we offer. They are between - 1/4" and 1/2" in length. NOTE: As trilobites grew, they shed their hard, protective, outer shell or exoskeleton. This process is referred to as molting. Most fossil trilobites are actually fossil trilobite molts. Pictured here is a small Elrathia kingi after it has shed it cheeks.
$ 4.00

Agnostid Trilobite - Agnostid trilobites of the species Peronopsis interstrictus were a small blind trilobite generally only a few mm long. The head (cephalon) and the rear (pygidium) are very near to each other in size and are of similar appearance. This specimen on a piece of Wheeler Shale was collected in Utah. Agnostids thrived during the Middle Cambrian period making them some 505 million years old. $ 8.00


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