Definition of orthoceratite in English:

orthoceratite

Pronunciation /ˌɔːθə(ʊ)ˈsɛrətʌɪt/

noun

(also orthoceratites)
  • A fossil shell of a nautiloid cephalod mollusc of the Palaeozoic or early Mesozoic eras, having a long, straight (or nearly straight) chambered shell; specifically a member of the former genus Orthoceratites or family Orthoceratidae; compare orthoceras . Also in Latin form Orthoceratites (in later use only as the name of a genus).

Origin

Mid 18th century; earliest use found in Philosophical Transactions of the Royal Society of London. From post-classical Latin Orthoceratites from ancient Greek ὀρθο- + κερατ-, κέρας horn + -ίτης.