fossil

Fossilized Echinoid Fragment (Calycinal/Boss Fossil)

Echinodermata fossil fragment

Hardness varies around 3 on the Mohs scale for calcitic remains, color ranges from off-white to beige or tan, dull or earthy luster, microcrystalline calcium carbonate (calcite) structure, no distinct cleavage.

Identified August 3, 2026More fossil →

Explore Fossilized Echinoid Fragment (Calycinal/Boss Fossil) in the encyclopedia →

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Physical properties

Formation & geological history

Formed in ancient shallow marine environments during the Paleozoic, Mesozoic, or Cenozoic eras, where calcareous remains of sea urchins or related echinoderms accumulated in sediment and underwent fossilization via mineral replacement.

Uses & applications

Valued primarily as a collectible fossil curiosity, for educational purposes, and by amateur paleontologists.

Geological facts

Sea urchins and their relatives (echinoids) often leave behind distinct button-like plates, tubercles, or internal molds (steinkerns) that weather out of limestone or chalk formations differently than the surrounding rock, making them appear raised or distinct.

Field identification & locations

Found weathering out of sedimentary limestone, chalk, or shale formations, often near ancient seabed exposures; easily identified by its symmetrical, often rounded protruding nodule attached to a flatter matrix.

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Crinoid Stem Fossil in Matrix

Phylum Echinodermata, Class Crinoidea

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Sedimentary Outcrop (Sandstone/Shale)

Sedimentary bedrock formation (variable composition)

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Chert with Fossil Brachiopod

Microcrystalline Quartz (SiO2) with Calcitic Brachiopod inclusion

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Fossilized Crinoid Stem in Limestone

Crinoidea (Class) in Calcium Carbonate (CaCO3) matrix

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Fossiliferous Limestone

Limestone with embedded fossil cross-section

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Fossiliferous Limestone with Crinoid stems

Limestone (CaCO3) containing Crinoidea fossils

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