Alaskoceras

Systematic Paleontology

Order: Tarphycerida

Family: Estonioceratidae

Genus: Alaskoceras

Alaskoceras is an estonioceratid genus from the lower Ordovician of the state of Alaska, moderately expanded, ribbed, with a divergant mature body chamber. The whorl section is slightly compressed, broadly rouded ventrally, more narrowly rounded dorsally. The siphuncle becomes marginal at maturity, connecting rings are thick-walled and layered.