Pterygotus

Pterygotus Temporal range: Llan. W L P Early Dev. Mid. Late Dev.
Fossils of P. anglicus
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Chelicerata
Order:	†Eurypterida
Superfamily:	†Pterygotioidea
Family:	†Pterygotidae
Genus:	†Pterygotus Agassiz, 1839
Type species
†Pterygotus anglicus Agassiz, 1849
Species
13 valid species †P. anglicus Agassiz, 1849 †P. arcuatus Salter, 1859 †P. barrandei Semper, 1898 †P. carmani Kjellesvig-Waering, 1961 †P. cobbi Hall, 1859 †P. denticulatus Kjellesvig-Waering, 1961 †P. floridanus Kjellesvig-Waering, 1950 †P. gaspesiensis Russell, 1953 †?P. grandidentatus Kjellesvig-Waering, 1961 †P. kopaninensis Barrande, 1872 †P. ludensis Salter, 1859 †P. wanggaii Ma et al., 2023. 6 dubious species †?P. australis McCoy, 1899 †?P. formosus (Dawson, 1861) †P. nobilis Barrande, 1872 †P. siemiradzkii Strand, 1926 †P. taurinus Salter, 1868 †?P. vernonensis Ruedemann, 1921
Synonyms
Genus synonymy Curviramus Ruedemann, 1935 Synonyms of P. anglicus P. atlanticus Clarke & Ruedemann, 1912 P. minor Woodward, 1864 Synonyms of P. barrandei P. beraunensis Semper, 1898 Synonyms of P. carmani Erettopterus serratus Kjellesvig-Waering, 1961

Pterygotus is an extinct genus of giant predatory eurypterid, a group of extinct aquatic arthropods. Fossils of Pterygotus have been discovered in deposits ranging in age from Middle Silurian to Late Devonian, and have been referred to several different species. Fossils have been recovered from five continents; Australia, Asia, Europe, North America and South America, which indicates that Pterygotus might have had a nearly cosmopolitan (worldwide) distribution. The type species, P. anglicus, was described by Swiss naturalist Louis Agassiz in 1839, who gave it the name Pterygotus, meaning "winged one". Agassiz mistakenly believed the remains were of a giant fish; he would only realize the mistake five years later in 1844.

Pterygotus was among the largest eurypterids. Isolated fossil remains of a large chelicera (frontal appendage) suggests that the largest known species, P. grandidentatus, reached a body length of 1.75 metres (5.7 ft). Several other species, notably P. anglicus at 1.6 metres (5.2 ft) was similarly gigantic. Pterygotus was surpassed in size by other giant eurypterids. Acutiramus was able to surpass 2 metres (6.6 ft), and Jaekelopterus could reach 2.6 metres (8.5 ft). Many species were considerably smaller than the largest species, such as P. kopaninensis at 50 centimetres (20 in). Pterygotus may have weighed around 30 kilogramms.

Like its close relative Jaekelopterus, Pterygotus was a large and active predator noted for its robust and enlarged cheliceral claws that would have allowed it to puncture and grasp prey and a visual acuity (clarity of vision) comparable to that of modern predatory arthropods.