Eurypterids Conservation status: Fossil
Scientific classification
Kingdom: Animalia Phylum: Arthropoda Class: Eurypterida Genus: Eurypterus
Orders
many, all extinct The conservation status of a species is an indicator of the likelihood of that species continuing to survive. ... File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Scientific classification or biological classification is how biologists group and categorize extinct and living species of organisms. ... Phyla Porifera (sponges) Ctenophora (comb jellies) Cnidaria Placozoa Bilateria Acoelomorpha Orthonectida Rhombozoa Myxozoa Superphylum Deuterostomia    Chordata (vertebrates, etc. ... Subphyla and Classes Subphylum Trilobitomorpha Trilobita - Trilobites (extinct) Subphylum Chelicerata Arachnida - Spiders, Scorpions, etc. ... Orders many, all extinct The eurypterids were the largest known arthropods that ever lived. ... Scientific classification or biological classification refers to how biologists group and categorize extinct and living species of organisms. ...

The eurypterids were the largest known arthropods that ever lived. They are members of the extinct class Eurypterida and predate the earliest fishes. The largest, such as Pterygotus, reached 2 meters or more in length, but most species were less than 20 cm. They were formidable predators among the coral reefs that thrived in the warm, shallow seas of the Silurian period, around 410 million years ago. Eurypterids were the most fearsome swimming predators of the Palaeozoic. Although called "sea scorpions", only the earliest ones were marine. 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 probably occurred by the Pennsylvanian period. Subphyla and Classes Subphylum Trilobitomorpha Trilobita - Trilobites (extinct) Subphylum Chelicerata Arachnida - Spiders, Scorpions, etc. ... Atlantic herring, Clupea harengus, the most abundant fish species in the world. ... This snapping turtle is trying to make a meal of a Canada goose, but the goose is too wary. ... Some of the biodiversity of a coral reef. ... Alternate use: The Silurians, a reptilian race from the science fiction series Doctor Who. The Silurian is a major division of the geologic timescale that extends from the end of the Ordovician period, about 439 million years before the present (BP), to the beginning of the Devonian period, about 408. ... This snapping turtle is trying to make a meal of a Canada goose, but the goose is too wary. ... The Palaeozoic is a major division of the geologic timescale, one of four geologic eras. ... The Pennsylvanian was also an Amtrak line until November 1, 2004. ...

Eurypterus is perhaps the most well-known genus of eurypterid, of which 200 fossil species are known. The genus Eurypterus was created in 1825 by James E. DeKay, a zoologist. He recognized the arthropod nature of the first ever described eurypterid specimen found by Dr. S. L. Mitchell. In 1984, Eurypterus remipes was named the State Fossil of New York. See genus (mathematics) for the use of the term in mathematics. ... FOSSIL is a standard for allowing serial communication for telecommunications programs under DOS. FOSSIL stands for Fido Opus Seadog Standard Interface Layer and was made by a group of Fidonet sysops to make their software work on different machines. ... 1984 is a leap year starting on Sunday of the Gregorian calendar. ... Though every state in the United States has a State Bird and a State Flower, not every state in the United States has a State Fossil. ... State nickname: Empire State Other U.S. States Capital Albany Largest city New York Governor George Pataki Official languages None Area 141,205 km² (27th)  - Land 122,409 km²  - Water 18,795 km² (13. ...

Body Structure

Though fossils are a bit unclear, the typical eurypterid had a large, flat, semicircular carapace, followed by a jointed section, and finally a tapering, flexible tail, with a long spine at the end. 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. Underneath, the creature had 8 pairs of jointed legs for walking, two small scorpion-like claws at the front (pedipalps). Other features, common to ancient and modern arthropods of this type, include ocelli, compound eyes, and chelicerae FOSSIL is a standard for allowing serial communication for telecommunications programs under DOS. FOSSIL stands for Fido Opus Seadog Standard Interface Layer and was made by a group of Fidonet sysops to make their software work on different machines. ... Ocelli is one of the types of photoreceptor organs in animals. ... Compound eye of a dragonfly A compound eye is a visual organ found in certain arthropods (some insects and crustaceans). ... The chelicerae of spiders are the mouth parts from which the fangs extend. ...

Although many eurypterids had legs too tiny to do more than allow them to crawl over the sea bottom, a number of forms had large stout legs, and were clearly capable of terrestrial locomotion (like land crabs today). While functional studies suggest that eurypterids used out-of-phase walking techniques, their trackways indicate that they used in-phase, hexapodous (six-legged) and octopodous (eight-legged) gaits. Some species may have been amphibious, emerging onto land for at least part of their life cycle. They may have been capable of breathing both in water and in air. For other uses, see Amphibian (disambiguation). ...

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. State nickname: Empire State Other U.S. States Capital Albany Largest city New York Governor George Pataki Official languages None Area 141,205 km² (27th)  - Land 122,409 km²  - Water 18,795 km² (13. ... Motto: Ut Incepit Fidelis Sic Permanet (Loyal she began, loyal she remains) Other Canadian provinces and territories Capital Toronto Largest city Toronto Lieutenant Governor James K. Bartleman Premier Dalton McGuinty (Liberal) Area 1,076,395 km² (4th)  - Land 917,741 km²  - Water 158,654 km² (14. ...

Eurypterids are related to the modern horseshoe crab and sea scorpion. About two dozen families of eurypterids are known. They went extinct in the Permian-Triassic extinction event. Binomial name Limulus polyphemus Linnaeus, 1758 The horseshoe crab (Limulus polyphemus), also known as king crab, is an arthropod that is more closely related to spiders than crabs. ... The Permian-Triassic extinction event, sometimes informally called the Great Dying, was an extinction event that occurred approximately 252 million years ago (mya), forming the boundary of the Permian and Triassic geologic periods. ...

References

• Ciurca, Samuel J. (1998). The Silurian Eurypterid Fauna (http://www.eurypterid.net/ ). Retrieved July 25, 2004.
• Clarke, John M. & Rudolf R. The Eurypterida of New York. Albany: New York State Education Department, 1912.