Article: Statoliths of Cenozoic teuthoid cephalopods from North America
Malcolm R. Clarke and John E. Fitch
Statoliths of fossil teuthoids are described in detail for the first time. Several hundred statoliths collected at eleven North American sites including Eocene, Oligocene, Miocene, Pliocene, and Pleistocene deposits are from fourteen kinds of teuthoid. These include six species of the family Loliginidae. Five new species, Loligo applegatei n. sp., L. mississippiensis n. sp., L. barkeri n. sp., L. valeriae n. sp., and L. stillmani n. sp. are extinct; L. opalescens is still living off California. The new ommastrephid species Dosidicus lomita n. sp. and Symplectoteuthis pedroensis n. sp. and the new onychoteuthid species Moroteuthis addicotti n. sp. are extinct species of genera which include species now living off California. Fossils of Berryteuthis differ from B. magister but have not been given a specific name. Four other kinds of Loligo statoliths are described but are immature or damaged and are not named. The genus Loligo is found as early as the Eocene while squids of the genera Dosidicus, Symplectoteuthis, Berryteuthis, and Moroteuthis were living in the Pliocene. The evolution of Loligo and the ecology of the species are discussed.