A synopsis of the Family Pterygotidae Clarke and Ruedemann 1912 (Eurypterida)

A review of the genera, species and subspecies of the family Pterygotidae. The Pterygotidae comprise two genera, Pterygotus Agassiz 1844 and Erettopterus Salter 1859, each of which is composed of two subgenera, Pterygotus (Pterygotus) Agassiz 1844, Pterygotus (Acutiramus) Ruedemann 1935, Erettopterus (Erettopterus) Salter 1859 and Erettopterus (Truncatiramus) Kjellesvig-Waering, 1961. Thirty-seven possible species and subspecies are recognized for P. (Pterygotus), seven for P. (Acutiramus), 17 for E. (Erettopterus) and six for E. (Truncatiramus). The stratigraphic range is from Middle Ordovician to Middle Devonian, while the geographical distribution is world wide, being known from all continents. The morphology of the chelicera of the pterygotids is reviewed, showing that this structure is composed of four joints, rather than three as commonly thought. Descriptions of undescribed specimens from Saaremaa (Oesel), Scotland, Libya, Bolivia, Northwest Territories (Canada), Pennsylvania and Maryland are given. Five new species are named and new morphological details given on other pterygotids. A complete checklist of the species as well as a catalog of the synonymy is included. The bibliography of the family is also included.