Eurypterid
A precursor to the earliest fishes and members of eurypterida, an extinct order, the eurypterids were the largest arthropods that ever lived. Eurypterids were the most fearsome swimming predators of the Palaeozoic. They ranged in length from six inches to six feet. While the earliest eurypterids may have lived in the sea, it is thought that most swam in small pools of fresh water. The move from the sea to fresh water probaby ocurred by the Pennsylvanian period.
Body Structure
Under the head of the eurypterids were twelve body segments known as tergites. The tail, which is spiked and may have been poisonous, is known as the telson. Some eurypterids have paddles, which were used to propel themselves through water. Some argue that the paddles were also used for digging.
Eurypterid Fossils
Eurypterid fossils have been found on nearly every continent. Locations currently producing excellent fossils include western New York State and southern Ontario, Canada in Silurian rock. Although relatively rare, the fossils are famous for excellent preservation. People seeking eurypterid fossils commonly search at Ridgemount Quarry, in Fort Erie, Ontario Canada. In 1984, eurypterus remipes was named the State Fossil of New York.
References
- Ciurca, Samuel J. (1998). The Silurian Eurypterid Fauna (http://www.eurypterid.net/). Retrieved July 25, 2004.