''Ctenopterus'' is a genus of prehistoric

eurypterid Eurypterids, often informally called sea scorpions, are a group of extinct marine arthropods that form the Order (biology), order Eurypterida. The earliest known eurypterids date to the Darriwilian stage of the Ordovician period, 467.3 Myr, mil ...

of the family Stylonuridae. It contains only one

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

, ''Ctenopterus cestrotus'' from the Early Silurian of

Otisville, New York Otisville is a village in Orange County, New York, United States. The population was 969 at the 2020 United States census, 2020 census. It is part of the Kiryas Joel, New York, Kiryas Joel–Poughkeepsie, New York, Poughkeepsie–Newburgh ...

, United States.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

Stylonurids, which lived from the

Ordovician The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era, and the second of twelve periods of the Phanerozoic Eon (geology), Eon. The Ordovician spans 41.6 million years f ...

to Lower

Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the s ...

periods, were small to very large forms with scales developing into tubercules and knobs. The prosoma (head) exhibited variable shape, with arcuate compound eyes located subcentrally, or anteriorly. Their abdomens were slender. Their walking legs were long and powerful, sometimes characterized by spines. Most genera did not have swimming legs. 1955. Merostomata. ''

Treatise on Invertebrate Paleontology The ''Treatise on Invertebrate Paleontology,'' published from 1953–2007 by the Geological Society of America and the University of Kansas, then 2009–present by the University of Kansas Paleontological Institute, is a definitive multi-authore ...

, Part P Arthropoda 2, Chelicerata'', P36. ''Ctenopterus'' is distinguished by its prosoma (head), which narrows towards the front. All of its legs are walking legs; the second and third pairs are strongly developed, with a double row of numerous flat spines; the last pair is long, without spines. ''Ctenopterus'' dates from the Silurian period. 1955. Merostomata. ''Treatise on Invertebrate Paleontology, Part P Arthropoda 2, Chelicerata'', P38.

References

Stylonuroidea Silurian eurypterids Fossils of the United States Eurypterids of North America Fossil taxa described in 1912 {{eurypterid-stub

Description

See also

References