Eurypterus remipes

Eurypterus remipes

Period

Silurian

Location

North America (New York)

Length

13-23 cm (up to 60 cm)

Weight

0.5-2 kg

Diet

Carnivore

Category

Marine Creatures - Marine Arthropods

Family

Eurypteridae

About Eurypterus remipes

Eurypterus remipes

Overview

Eurypterus remipes is the most famous of the "sea scorpions" and the official state fossil of New York! This remarkable arthropod lived approximately 410 million years ago during the Silurian period, swimming through the shallow, brackish waters that once covered much of eastern North America.

Taxonomy & Classification

  • Phylum: Arthropoda
  • Order: Eurypterida
  • Family: Eurypteridae
  • Diet: Carnivorous
  • Locomotion: Swimming and walking

Despite being called "sea scorpions," eurypterids were only distantly related to modern scorpions. They're actually closer to horseshoe crabs and spiders!

Physical Characteristics

Size & Build

  • Length: Usually 13-23 cm (5-9 inches)
  • Largest specimens: Up to 60 cm (24 inches)
  • Body Type: Flattened, streamlined for swimming

Distinctive Features

  • Armored head (prosoma) similar to horseshoe crabs
  • Compound eyes positioned on top of the head
  • Four pairs of walking legs for crawling on the seafloor
  • One pair of swimming paddles (modified legs) for propulsion
  • Pointed tail spine (telson)—NOT a stinger!

Not Actually Venomous!

Common Misconception

Despite the scorpion-like appearance:

  • The tail was NOT used to deliver venom
  • Used for steering while swimming
  • May have helped with balance
  • The "scary" look was just for show!

Habitat & Lifestyle

Brackish Water Dweller

Eurypterus lived in:

  • Shallow lagoons and coastal waters
  • Brackish environments (mix of salt and fresh water)
  • Areas that are now New York and surrounding regions

Hunting Behavior

  • Likely hunted small fish and invertebrates
  • Used walking legs to stir up sediment
  • Grabbed prey with front appendages
  • Could both swim and walk on the seafloor

Discovery & Significance

A Scientific First

  • First fossils found in 1818 near Westmoreland, New York
  • Initially mistaken for a fossil catfish!
  • Correctly identified in 1825 by James Ellsworth De Kay
  • He named both the species AND created the genus Eurypterus

State Fossil of New York

  • Designated state fossil in 1984 by Governor Mario Cuomo
  • Abundant fossils found in the Bertie Formation
  • Fossils occur along the route of the New York Thruway
  • One of the most common eurypterid fossils found

The Eurypterid Family

Giants of the Group

While Eurypterus was relatively small, its relatives could be huge:

  • Pterygotus: Up to 2.3 meters (7.5 feet)
  • Jaekelopterus: Up to 2.5 meters (8.2 feet)—the largest arthropod EVER!

Eurypterus was like a "regular-sized cousin" in a family of giants.

Evolutionary Importance

Bridge to Land

Eurypterids are important because:

  • They show early arthropod diversity
  • Some may have ventured onto land occasionally
  • Related to the ancestors of arachnids (spiders, scorpions)
  • Help us understand the Silurian ecosystem

Cool Facts

  • Eurypterus is the state fossil of New York—chosen because so many fossils are found there!
  • The name means "broad wing" referring to its swimming paddles
  • First mistaken for a catfish when discovered in 1818
  • Despite looking scary, the tail was NOT venomous
  • More closely related to spiders than to modern scorpions
  • Fossils are so common in New York that you can find them yourself in some locations!
  • They breathed through gills on their legs
  • Some scientists think they could survive brief trips onto land

Eurypterus remipes represents one of nature's early experiments in arthropod design—a swimming predator that patrolled ancient seas long before fish ruled the oceans!