Eurypterid arthropod — Eurypterus remipes

Geologic period: Silurian

Age: More than 415 million years old.

Feeding: Predatory or scavenging behavior is inferred from anatomy and eurypterid biology.

Locomotion: Aquatic movement using limbs adapted for crawling and swimming.

Body plan: Segmented body with a broad front region, paired appendages and a tapering abdomen.

Evidence: Exoskeleton and appendage anatomy are fossil evidence; behavior is reconstructed.

Why it matters: Eurypterids were among the prominent arthropods of Paleozoic waters and were relatives of the chelicerate lineage.

Plain Language Identity: An aquatic eurypterid, commonly called a sea scorpion.

What You Are Looking At: The fossilized external skeleton of an aquatic chelicerate arthropod.

Ecosystem: Silurian shallow-water environment.

Preservation: Mineralized or compressed arthropod exoskeleton.

Find Location: Smithsonian highlights material from New York State.

Open Questions: The nickname 'sea scorpion' describes resemblance and relationship; it was not a true modern scorpion.

Source Urls: https://naturalhistory.si.edu/visit/virtual-tour/current-exhibits/deep-time-virtual-tour-fossil-list; https://nysm.nysed.gov/exhibitions/windows/eurypterid

Enrichment Method: SAGE curated research pass; title and scientific name matched; evidence separated from inference

Scientific name: Eurypterus remipes

Evidence / representation: Representative evidence-type visual; not the exact specimen.

Representative evidence-type visual; not the exact specimen.

Oceans Before Dinosaurs: The Rise of Complex Animal Life.