Eurypterid (Sea Scorpion) Fossil
Eurypterus cf. remipes • Body fossil and carbonaceous impression of an invertebrate
Geological Period
Silurian to Devonian
Estimated Age
419 to 443 million years old
Preservation Type
Carbonization and flattened impression in sedimentary rock, preserving the organic exoskeleton remnants as a dark carbonaceous film.
Condition Assessment
Fair to Good. The specimen is partially articulated with clear segment outlines, though missing appendages and showing some matrix fracturing and repair along the central axis.
Taxonomic Classification
Phylum Arthropoda, Subphylum Chelicerata, Order Eurypterida
Morphological Description
Elongated, segmented body plan showing overlapping tergites with curved pleural margins and a distinct central axis. The specimen displays preserved cuticular remnants forming a dark carbonized film outlining the body segments, revealing the anatomical layout of the dorsal or ventral plate arrangement.
Rock Matrix
Fine-grained argillaceous siltstone or dolomitic shale with brownish-grey weathering and minor iron-oxide staining.
Formation & Location
Bertie Formation, New York, USA, or similar Silurian-Devonian eurypterid-bearing Lagerstätten globally.
Size & Dimensions
Approximately 15 cm in length and 4 cm in maximum width, consistent with medium-sized adult specimens of the taxon.
Value & Rarity
Estimated Market Value
$150 - $400
Auction Estimate
$200 - $500
Rarity Assessment
Uncommon, though classic localities yield localized concentrations of eurypterid material.
Scientific Significance
Provides valuable insight into early Paleozoic aquatic apex predators, shallow marine to brackish ecosystems, and the soft-tissue or cuticular preservation of arthropod exoskeletons.
Preparation Recommendations
Mechanical preparation using fine pneumatic air scribes under magnification to expose hidden margins, followed by stabilization with a dilute, reversible acrylic consolidant if needed.
Notable Features
Clear preservation of metameric segmentation lines and the central axis, presenting a distinct silhouette of the arthropod body against the contrasting matrix.