Megalograptidae

Megalograptidae Temporal range: Ordovician PreЄ Є O S D C P T J K Pg N
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Merostomata
Order:	†Eurypterida
Suborder:	†Eurypterina
Superfamily:	†Megalograptoidea
Family:	†Megalograptidae Caster & Kjellesvig-Waering, 1955
Species
See text

Megalograptidae is an extinct family of eurypterids.

Description

Megalograptids are characterized by large exoskeletons with ovate to triangular scales. The prosoma (head) is subquadrate, with a tonguelike anterior process bearing marginal spines, and compound eyes on the top front of the head. The chelicerae (claws in front of the mouth) are small and short. The first and third pairs of walking legs are short, with diverging or closely spaced spines. The second pair of walking legs is enormously developed, with long paired spines. The fourth pair of walking legs are nearly spineless. The preabdomen, the front portion of the body, is narrow with axial furrows, while the postabdomen is moderately narrow with broad, flat and curved appendages on the last body segment. The telson is short and lanceolate.^[1]

Genera

• Class Merostomata Dana, 1852
• Order Eurypterida Burmeister, 1843
• Suborder Eurypterina Burmeister, 1845
• Superfamily Megalograptoidea Caster & Kjellesvig-Waering, 1955

  Family Megalograptidae Caster & Kjellesvig-Waering, 1955

  Genus Megalograptus Miller, 1874

  Megalograptus alveolatus (Shuler, 1915)

  Megalograptus ohioensis Caster & Kjellesvig-Waering, 1955

  Megalograptus shideleri Caster & Kjellesvig-Waering, 1964

  Megalograptus welchi Miller, 1874

  Megalograptus williamsae Caster & Kjellesvig-Waering, 1964

  Genus Echinognathus Walcott, 1882

  Echinognathus clevelandi Walcott, 1882

  Genus Pentecopterus Lamsdell, James C et al., 2015

  Pentecopterus decorahensis Lamsdell, James C et al., 2015

See also

• List of eurypterids

References

1. Størmer, L 1955. Merostomata. Treatise on Invertebrate Paleontology, Part P Arthropoda 2, Chelicerata, P36.