Erettopterus

Erettopterus
Temporal range: RhuddanianLochkovian 443.7–412.3 Ma
Fossil of E. bilobus at the Natural History Museum, Vienna.
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Chelicerata
Order: Eurypterida
Superfamily: Pterygotioidea
Family: Pterygotidae
Genus: Erettopterus
Salter in Huxley & Salter, 1859
Type species
Erettopterus bilobus
Salter, 1856
Species
19 species
  • E. bilobus
    Salter, 1856
  • E. brodiei
    Kjellesvig-Waering, 1961
  • E. canadensis
    Dawson, 1879
  • E. carinatus
    Kjellesvig-Waering, 1979
  • E. exophthalmus
    Kjellesvig-Waering & Leutze, 1966
  • E. gigas
    Salter in Huxley & Salter, 1859
  • E. globiceps
    Clarke & Ruedemann, 1912
  • E. grandis
    Pohlman, 1881
  • E. holmi
    Størmer, 1934
  • E. laticauda
    Schmidt, 1883
  • E. marstoni
    Kjellesvig-Waering, 1961
  • E. megalodon
    Kjellesvig-Waering, 1961
  • E. osiliensis
    Schmidt, 1883
  • E. saetiger
    Kjellesvig-Waering, 1964
  • E. serratus
    Kjellesvig-Waering, 1961
  • E. serricaudatus
    Kjellesvig-Waering, 1979
  • E. spatulatus
    Kjellesvig-Waering, 1961
  • †?E. vogti
    Størmer, 1934
  • E. waylandsmithi
    Kjellesvig-Waering & Caster, 1955
Synonyms
  • Himantopterus Salter, 1856, preoccupied
  • Truncatiramus Kjellesvig-Waering, 1961

Erettopterus is a genus of large predatory eurypterid, an extinct group of aquatic arthropods. Fossils of Erettopterus have been discovered in deposits ranging from Early Silurian (the Rhuddanian age) to the Early Devonian (the Lochkovian age), and have been referred to several different species. Fossils have been recovered from two continents; Europe and North America. The genus name is composed by the Ancient Greek words ἐρέττω (eréttō), which means "rower", and πτερόν (pterón), which means "wing", and therefore, "rower wing".

Erettopterus is classified as part of the eurypterid family Pterygotidae, a family differentiated from other eurypterids by their flattened telsons (the most posterior segment of the body) and their modified chelicerae (frontal appendages), ending in well-developed chelae (claws). Although some pterygotid eurypterids, such as Jaekelopterus or Acutiramus grew to gigantic proportions, it is estimated that the largest species of Erettopterus, E. osiliensis, reached 90 cm (35 in). Erettopterus had a bilobed (divided into two lobes) telson, which is its main characteristic. The forms of chelicerae are very diverse between species, but they are generally very long with small curved teeth without serrations.

Studies on the chelicerae and compound eyes of Erettopterus have revealed that it was a predator with high visual acuity, but it was not as highly specialized or active as Jaekelopterus and Pterygotus, it was more like Slimonia acuminata, and probably used its enlarged chelicerae for grasping rather than a more specialized feeding.