''Strobilopterus'' is a genus of prehistoric eurypterid of the family

Strobilopteridae Strobilopteridae is an extinct family of eurypterids that lived in the Silurian and Devonian periods. The family is one of three families contained in the superfamily Eurypteroidea (along with Dolichopteridae and Eurypteridae), which in turn is ...

. The genus contains four species, two from the

Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, whe ...

Wyoming Wyoming () is a U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the south ...

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

(''S. princetonii'' and ''S. proteus''), one from the Devonian of

Ohio Ohio () is a state in the Midwestern region of the United States. Of the fifty U.S. states, it is the 34th-largest by area, and with a population of nearly 11.8 million, is the seventh-most populous and tenth-most densely populated. The sta ...

, United States (''S. richardsoni'') and one from the

Silurian The Silurian ( ) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the shortest period of the Paleozo ...

Estonia Estonia, formally the Republic of Estonia, is a country by the Baltic Sea in Northern Europe. It is bordered to the north by the Gulf of Finland across from Finland, to the west by the sea across from Sweden, to the south by Latvia, a ...

(''S. laticeps'').Dunlop, J. A., Penney, D. & Jekel, D. 2015. A summary list of fossil spiders and their relatives. In World Spider Catalog. Natural History Museum Bern, online at http://wsc.nmbe.ch, version 16.0 http://www.wsc.nmbe.ch/resources/fossils/Fossils16.0.pdf (PDF).

Description

Strobilopterus proteus subadult and adult

''Strobilopterus'' was a large strobilopterid eurypterid, with adults of the species ''S. proteus'' measuring approximately 15 to 20 centimetres in length. The

carapace A carapace is a Dorsum (biology), dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tor ...

of ''Strobilopterus'' was wide and semicircular in shape, with the lateral eyes lunate to crescentic with the palpebral lobe between the central and centrimesial sectors. The first pair of appendages were small, lacking denticles, and the subsequent four pairs of appendages were likewise also small, but with fixed spines and serrated distal

podomere The arthropod leg is a form of jointed appendage of arthropods, usually used for walking. Many of the terms used for arthropod leg segments (called podomeres) are of Latin origin, and may be confused with terms for bones: ''coxa'' (meaning hip, pl ...

margins. The sixth and last pair of appendages were short but were powerfully serrated on the anterior margins of the podomeres. The type A genital appendage was long and undivided, the type B appendage was more oval in shape.

References

Eurypteroidea Devonian eurypterids Fossils of the United States Eurypterids of North America Silurian eurypterids Eurypterids of Europe {{Eurypterid-stub