Acutiramus

Acutiramus
Temporal range: Late Silurian–Early Devonian
Illustration of Acutiramus cummingsi
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Merostomata
Order: †Eurypterida
Superfamily: †Pterygotioidea
Family: †Pterygotidae
Genus: †Acutiramus
Ruedemann, 1935
Species

See text

Acutiramus is an extinct genus[1] of eurypterid which lived in the Late Silurian (Ludlow) to Early Devonian.

Acutiramus is one of the largest eurypterids with pincers 5 cm and length about 2 m. It is related to another large eurypterid, Pterygotus.

Description

Restoration of A. cummingsi

Pterygotidae, which lived from the Ordovician to Devonian periods, were characterized by small to large exoskeletons with semilunar scales. The telson, (tail) was expanded, or flatter than it was tall. Pterygotidae also had chelicerae (claws in front of the mouth) that were large and long, with strong, well developed teeth on the claws. Their walking legs were small and slender, without spines.[2]

Acutiramus is distinguishable from other Pterygotidae by the distal margin of the chelae, where the final tooth is at an acute angle to the rest of the claw (hence the name Acutiramus, or “acute arm”). The large tooth in the center of the claw is distally inclined, which is to say it points forwards. The prosoma (head) is subquadrate, with compound eyes located at the edge of the front corners. The telson has a low row of knobs running down its center.[2]

Species

Gallery

See also

References

  1. ↑ Tollerton, V. P. Jr 1997 "The Type Species of the Eurypterid Genus Acutiramus Ruedemann, 1935" Journal of Paleontology 71(5):950-951
  2. ↑ 2.0 2.1 Størmer, L. 1955. Merostomata. Treatise on Invertebrate Paleontology, Part P Arthropoda 2, Chelicerata, P: 30–31.

External links