Sea Scorpion

Eurypterus remipes is a eurypterid, an extinct group of arthropods related to modern horseshoe crabs and scorpions. Despite its common name, the sea scorpion was not a true scorpion and spent its life in water. It is probably the most abundantly preserved eurypterid in the fossil record, and New York's Silurian rock layers have produced more specimens than anywhere else on Earth.

The Bertie Formation of western New York, a sequence of thinly layered dolostone and shale deposited in a shallow, partially enclosed sea, is the classic source for these fossils. Eurypterus remipes specimens found there are often preserved in remarkable detail, with legs, paddles, and body segments still intact.

Eurypterus remipes was a flat-bodied, segmented arthropod with six pairs of appendages. The hindmost pair were broad, oar-shaped paddles used for swimming, which gives the genus its name: Eurypterus means 'broad wing.' The other appendages included walking legs and smaller claws near the mouth for handling food. Most specimens from New York are 5 to 8 inches long, though some reached 13 inches (33 cm).

The sea scorpion hunted small fish, trilobites, and other invertebrates in the shallow, briny waters of the Silurian sea. It could swim actively or walk along the seafloor. The Bertie Formation preserves large numbers of individuals together, which may record molting events rather than mass deaths: eurypterids shed their exoskeletons to grow, leaving behind intact shells that look like complete animals.

Eurypterus remipes was first described in 1825 from specimens found in New York. For most of the 19th and early 20th centuries, the western New York limestone quarries that exposed the Bertie Formation were the world's primary source of eurypterid fossils. The species became well known to paleontologists and collectors long before the state fossil designation.

New York designated Eurypterus remipes its official state fossil in 1984. By then the species had been studied from New York material for nearly 160 years, the Bertie Formation was already the world's reference collection for eurypterids, and no other state had a stronger claim.

The Bertie Formation outcrops in a band across western New York, running through Erie, Niagara, Orleans, and Monroe counties. The Williamsville area east of Buffalo has produced classic Eurypterus remipes specimens from limestone and dolostone layers exposed in former quarry cuts. The formation is also exposed along stream banks and road cuts across the same corridor.

The New York State Museum in Albany holds one of the finest eurypterid collections in the world, including exceptionally preserved Bertie Formation specimens. The Buffalo Museum of Science also has significant local Silurian material.