Parastylonurus Temporal range: Silurian PreꞒ Ꞓ O S D C P T J K Pg N
Life restoration of P. ornatus.
Restoration of the sixth limb of P. ornatus.
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Chelicerata
Order:	† Eurypterida
Superfamily:	† Stylonuroidea
Family:	† Parastylonuridae Waterston, 1979
Genus:	† Parastylonurus Kjellesvig-Waering, 1966
Species
†P. hendersoniWaterston, 1979 †P. ornatusLaurie, 1892 (type species)

Parastylonurus is a genus of prehistoric eurypterid. It is the only genus classified in the family Parastylonuridae ^[1] and contains two species, P. hendersoni and P. ornatus from the Silurian of Scotland. ^[1]

Contents

• Description
• Classification
• Species
• See also
• References

Description

Parastylonurus was a stylonuroid of small to medium size with a rounded prosoma wider than it was long. The eyes were located on the anterior half of the carapace and the metasoma was very long. The first three walking legs were very short with single opposable spines on every joint. The last two walking legs were very long, reaching to the last tergite. The opisthosoma was narrow and undifferentiated and the telson was spike-like. ^[2]

Classification

Parastylonurus can be differentiated from the closely related Stylonurus in that it lacks the distinct trilobation present in Stylonurus and by the position of the eyes. ^[2]

Species

Parastylonurus contains two valid species, ^[1] with other named species now seen as invalid or as part of other genera.

• Parastylonurus hendersoniWaterston, 1979 - Pentland Hills, Scotland (Silurian)
• Parastylonurus ornatusLaurie, 1892 - Scotland (Silurian)

Invalid or reassigned species are listed below:

• "Parastylonurus" beecheri ^[2] Hall, 1884 - Pennsylvania, USA (Devonian), reclassified as a species of Stylonurella, ^[3] then designated as a nomen dubium . ^[1]
• "Parastylonurus" macrophthalmus ^[2] Laurie, 1892 - Pentland Hills, Scotland (Silurian), reclassified as a species of Hardieopterus . ^[3]
• "Parastylonurus" megalops ^[2] Salter, 1859 - Herefordshire, England (Silurian), reclassified as a species of Hardieopterus . ^[3]
• "Parastylonurus" myops ^[2] Clarke, 1907 - Eastern USA (Silurian), reclassified as a species of Hardieopterus . ^[3]
• "Parastylonurus" rusti ^[4] Ruedemann, 1926 - New York, USA (Ordovician), a pseudofossil. ^[3]
• "Parastylonurus" sigmoidalisKjellesvig-Waering, 1971 - Shropshire, England (Silurian), reclassified as a species of Athenepterus . ^[1]

See also

• List of eurypterids

References