Hallipterus

Hallipterus is a genus of prehistoric eurypterid classified as part of the family Hardieopteridae.^[1]

Hallipterus Temporal range: Devonian, 383.7–376.1 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Carapace of H. excelsior
Reconstruction after Tetlie (2008)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Chelicerata
Order:	†Eurypterida
Superfamily:	†Kokomopteroidea
Family:	†Hardieopteridae
Genus:	†Hallipterus Kjellesvig-Waering, 1963
Type species
†Hallipterus excelsior Hall, 1884
Synonyms
Dolichocephala Claypole, 1883

Description

Life restoration, 2nd and 3rd pairs of legs are speculative

Hallipterus was a gigantic Hardieopterid eurypterid. Though some previous estimates have placed its size at over 1.5 meters in length, these were likely excessive.^[1] Still, assigned specimens suggest a size of over 1 meter long.^[1]

The carapace was subelliptical, greater in length than in width, with a prominent and unornamented marginal rim. The eyes were very small, close to each other and separated by a prominent median ridge with large ocelli at the posterior extremity.^[2]

The chelicerae were simple and elongated. The first walking legs possessed flat and movable spines. The rest of the legs and the opisthosoma remain unknown.^[2]

Species

Hallipterus contains one valid species, H. excelsior, from the Devonian of New York.^[3] Another species was once recognized from similarly aged deposits in Pennsylvania, "H. lacoanus",^[2] but it is today seen as synonymous with H. excelsior.^[1]

See also

• List of eurypterids