Kokomopteroidea

Kokomopteroidea Temporal range: Early Silurian - Late Devonian, 442–358.9 Ma PreЄ Є O S D C P T J K Pg N
Reconstruction of Kokomopterus, a kokomopterid.
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Chelicerata
Class:	Merostomata
Order:	†Eurypterida
Suborder:	†Stylonurina
Superfamily:	†Kokomopteroidea Kjellesvig-Waering, 1966
Families
†Kokomopteridae †Hardieopteridae

Kokomopteroidea is an extinct superfamily of eurypterids, an extinct group of merostomatan arthropods commonly known as "sea scorpions". It is one of four superfamilies classified as part of the suborder Stylonurina. Kokomopteroids have been recovered from deposits of Early Silurian to Late Devonian age in the United States and the United Kingdom.

Kokomopteroids are stylonurines with a spiniferous appendage V and a posterior notch on the metastoma. The superfamily forms two distinct clades; the Kokomopteridae (including the genera Kokomopterus and Lamontopterus) and the Hardieopteridae (including the genera Hardieopterus, Tarsopterella and Hallipterus).

The Kokomopteroidea retains primitive Hughmilleria-type prosomal appendages for unsuitable raking through the bottom sediments of marine environments. As such, the members of the superfamily were likely scavengers. The Hardieopteridae display some sweep-feeding characteristics similarly to members of the superfamilies Hibbertopteroidea and Stylonuroidea, including a broadening of the metastoma and the spines of the anterior prosomal appendages. Hardieopterids may even have been benthic bottomdwellers partially living buried in the substrate.

The Kokomopteroids are eurypterids classified as part of the suborder Stylonurina. They are a sister group to the Hibbertopteroidea, united by a median ridge on the carapace between the lateral eyes and a distal thickening to the podomeres of the prosomal appendages. The primitive hibbertopteroid Drepanopterus is a sister taxon to all other hibbertopteroids and shares certain characteristics with the Kokomopteroidea (such as a clavate telson).