EURYPTERID (SEA SCORPION) FOSSILS FOR SALE
What Is A Eurypterid?
Eurypterids are an extinct order of arthropods, commonly called Sea Scorpions. The order is known by 250 species including the largest known arthropod. Eurypterids are related to modern arthropods like spiders, scorpions, and horseshoe crabs.
When Did Eurypterids Appear In The Fossil Record?
Eurypterids first appear in the Darriwilian stage of the Ordivician about 467.3 million years ago. Their diversity expanded greatly during the Silurian Period.
When Did Eurypterids Go Extinct?
Eurypterids went through several stages of declining diversity before their ultimate extinction. The Late Devonian Extinction caused all but four families of Eurypterid disappear from the fossil record. The last remaining members of the order Eurypterida disappeared during or shortly after the Permian-Triassic extinction about 252 million years ago.
What Did Eurypterids Look Like?
Eurypterid bodies consisted of a horseshoe crab like shell head, segmented body and a tail-like appendage called a telson. They had six pairs of appendages under the shell of the head and eyes above. The first set of appendages were modified into pincers for getting food to the mouth. The remaining sets were used for locomotion. The last set of appendages were either wide and flat like paddles for swimming or long and thin like legs for walking.
How Big Were Eurypterids?
Most Eurypterids were smaller than about 8 inches (20cm) with the smallest being 1.2 inches (3 cm). One species, Jaekelopterus rhenaniae was the largest arthropod known at, 8.2 feet (2.5 meters). There were other large species ranging between 20 inches (50 cm) and 6 feet (180 cm).
How Did Eurypterids Move?
Eurypterids had two basic forms of locomotion, swimmers and walkers. There were two subfamilies that were differentiated by the way they move. Eurypterina had its last set of appendages modified into a set of blade shaped paddles for swimming. Stylonurina had this same pair of appendages modified into a strong, thin set of legs for walking. It is likely that both subfamilies swam and walked or crawled. It is also likely that Stylonurina could leave the water at least for a short time as it had legs, while Eurypterina would have been confined to the water.
What Did Eurypterids Eat?
Eurypterids were carnivores. It is likely they ate whatever they could safely subdue, fish, invertebrates, etc. Fossilized Eurypterid coprolites (feces) have been found and contained Trilobite and Eurypterid shells, indicating that they were also cannibalistic. Given their diversity and morphology it is likely that Sea Scorpions were among the apex predators of the environments they inhabited.
Where Did Eurypterids Live?
Despite often called Sea Scorpions, most Eurypterids lived in brackish or freshwater. Only the early species that lived in the Ordovician Period lived in marine environments. Most were probably living in brackish water where fresh and saltwater mixed. The last living Eurypterids were freshwater dwellers.
How Did Eurypterids Breath On Land?
It is not known if they actually could breath on land or if they could simply survive out of the water for a few hours. No fossilized breathing apparatus has been found. If they were breathing out of the water it is likely a modification of their vascular system that would allow for oxygen exchange.
What Is The Difference Between Sea Scorpions And Modern Scorpions?
Sea Scorpion is the common name for members of the arthropod order, Euryptida. Scorpions are members of the order Scorpiones, class Arachnida. They are taxonomically only distantly related. Sea Scorpions were aquatic while scorpions are terrestrial. Perhaps the biggest differences are in the tail and pincers. The tail of the Sea Scorpion resembles the stinger of a scorpion but was not used to deliver venom. The pincers of the Sea Scorpion are the first set of appendages under the shell while a scorpion’s pincers are the second set of appendages. Relationship between Eurypterid and the first terrestrial arachnids is not well understood.
What Is The Closest Living Relative Of Eurypterids?
The four living species of Horseshoe Crab are the closest living relatives of the Eurypterids.
Did You Know?
A Eurypterid, Eurypterus remipes was designated as the state fossil of New York.