A single specimen of the axial skeleton of an elongate fossil stromateoid fish, collected from the Upper Miocene (Messinian) St. Eugčne locality of north-western Algeria, is identified as a new species Ariomma geslini sp. nov. of the family Ariommatidae. It is based on a unique combination of features, including morphology and arrangement of pleural ribs, structure and orientation of anterior portion of the anal fin, unique sequential arrangement of anal-fin pterygiophores in relation to the haemal spines, and presence of large cycloid scales and meristics. The morphology and orientation of the first anal-fin pterygiophore indicate that A. geslini sp. nov. is probably related to the amphi-Atlantic species A. bondi and A. melanum. The analysis of the fossil record of the Stromateoidei suggests that the ariommatids were already in existence at least as early as the Eocene.

Key words: Teleostei, Perciformes, Ariommatidae, Miocene, Messinian, Algeria.

Giorgio Carnevale carnevale@dst.unipi.it, CNR - Istituto di Geoscienze e Georisorse and Dipartimento di Scienze della Terra, via S. Maria, 53 I-56126 Pisa, Italia; Alexandre F. Bannikov aban@paleo.ru, Paleontological Institute, Russian Academy of Sciences, Profsoyuznaya 123, Moscow 117997, Russia