trans-Saharan seaway The marine seaway that, during two intervals in the Late Cretaceous, extended from Tethys in the north through what are now Libya, Chad, Niger, and Nigeria, to the newly developing S. Atlantic Ocean. On both occasions ammonite (Ammonoidea) and ostracod (Ostracoda) faunas are known to have migrated through this seaway. The first event was in the latest Cenomanian and earliest Turonian, and was re-established only in the Late Campanian to Early Maastrichtian interval. At the southern end (in present-day Nigeria) there was a structural control in the form of the Benue Trough, but the remainder of the seaway appears to have been controlled only by global sea level change.

trans-Saharan seaway The marine seaway that extended from Tethys in the north through what are now Libya, Chad, Niger, and Nigeria, to the newly developing South Atlantic Ocean during two intervals in the Late Cretaceous. On both occasions ammonite and ostracod faunas are known to have migrated through this seaway. At the southern end (in present-day Nigeria) there was a structural control in the form of the Benue Trough, but the remainder of the seaway appears to have been controlled only by global sea-level change.