Rock Identifier
Trilobite Fossil (Phylum Arthropoda, Subphylum Trilobita) — fossil
fossil

Trilobite Fossil

Phylum Arthropoda, Subphylum Trilobita

AI-generated identification · may be incorrect

Hardness varies depending on mineral replacement, typically calcite (Mohs 3); color ranges from grey to brown; dull to earthy luster; distinct three-lobed, segmented exoskeleton structure.

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Physical properties

Hardness varies depending on mineral replacement, typically calcite (Mohs 3); color ranges from grey to brown; dull to earthy luster; distinct three-lobed, segmented exoskeleton structure.

Formation & geological history

Formed through the fossilization of marine arthropods that lived in ancient Paleozoic seas, approximately 250 to 521 million years ago.

Uses & applications

Valued primarily as a scientific specimen, educational tool, and popular collectible for fossil enthusiasts.

Geological facts

Trilobites are one of the earliest well-known groups of arthropods and serve as excellent index fossils for dating Paleozoic rocks.

Field identification & locations

Found worldwide in sedimentary marine shales and limestones; identified by their characteristic three-lobed body shape.

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Bioclastic limestone, composed chiefly of calcite (CaCO₃)

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