fossil

Fossil trilobite

Trilobita (likely a spiny or enrolled trilobite; exact genus unclear)

AI-generated identification · may be incorrect

A three-lobed, segmented exoskeleton preserved in tan-brown sedimentary rock; original trilobite calcite/chitinous shell is commonly replaced or coated by iron oxides. Matrix hardness is typically about 3–5 Mohs, with earthy to dull luster and no visible crystal cleavage.

Identified September 13, 2026More fossil →

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Physical properties

Formation & geological history

Trilobites were extinct marine arthropods that lived from the Early Cambrian to the end-Permian, about 521–252 million years ago. This specimen likely represents burial and mineral replacement in shale or limestone, followed by weathering and preparation.

Uses & applications

Primarily a teaching, display, and collecting specimen; scientifically important for biostratigraphy and interpreting ancient marine environments.

Geological facts

Trilobites molt their exoskeletons, so many fossils are shed shells rather than carcasses. The distinctive axial lobe and repeated thoracic segments are characteristic.

Field identification & locations

Identify by the segmented body, central axial lobe, and paired lateral lobes; common sources include Morocco, China, the United States, and Russia. Professional preparation and locality data strongly affect authenticity and value.