Pterygotioidea (the name deriving from the type genus Pterygotus, meaning "winged one") is a superfamily of eurypterids, an extinct group of aquatic arthropods.

The group includes the basal and small hughmilleriids, the larger and specialized slimonids and the famous pterygotids which were equipped with robust and powerful cheliceral claws.

[3][4] Like all other chelicerates, and other arthropods in general, pterygotioid eurypterids possessed segmented bodies and jointed appendages (limbs) covered in a cuticle composed of proteins and chitin.

[6] In derived members of the group, Slimonidae and Pterygotidae, the telson (the posteriormost segment of the body) was expanded and flattened, often with a spike protruding from its end.

This function is retained in the more basal Hughmilleriidae and Slimonidae, but pterygotid chelicerae were large and long with strong and well developed teeth on specialized chelae (claws).

Its describer, the American geologist Clifton J. Sarle, considered the genus to represent an intermediate form between the more basal Eurypterus and the derived Pterygotus but did not assign Hughmilleria to any particular family.

[13] The family Pterygotidae was erected in 1912 by John Mason Clarke and Rudolf Ruedemann to constitute a group for the genera Pterygotus, Slimonia, Hastimima and Hughmilleria.

[11] American paleontologist Erik N. Kjellesvig-Waering emended the Pterygotidae in 1951, referring the genera Hastimima, Hughmilleria and Slimonia, and the newly named Grossopterus, to their own family within the Eurypteracea, Hughmilleriidae, leaving Pterygotus as the sole pterygotid genus.

[11] In 1955, Norwegian paleontologist and geologist Leif Størmer considered the pterygotid clade to represent a family within the eurypterid superfamily "Eurypteracea".

Pterygotioids appear to have been relatively abundant throughout the Silurian and Devonian world, with unusually (in terms of eurypterids, most groups being absent entirely) large numbers recovered from the ancient continent of Gondwana (composed of Africa, India, South America, Australia and Antarctica).

[18] The earliest known pterygotioids, belonging to the genus Hughmilleria, are from the Llandovery epoch of the Silurian and appear around the same time in Laurentia, Scotland and South China.

[18] It remains unclear whether pterygotioids were capable of crossing oceans on a regular basis or if species recovered outside of Laurentia, Baltica and Avalonia represent isolated occurrences.