Fish otoliths from the Lutetian of the Aquitaine Basin (SW France), a breakthrough in the knowledge of the European Eocene ichthyofauna

摘要

The fossil otolith assemblages of the Aquitaine Basin (SW France) have been extensively studied for more than 30 years and are among the best documented worldwide. However, Lutetian otoliths are less well known than those from the lower and upper Eocene. A new collection of > 11,000 otoliths from the Lutetian Miretrain Marl Formation from five different localities in Peyrehorade and the Donzacq Marl Formation at Saint-Geours-d'Auribat is analysed here. The oldest site at Saint-Geours-d'Auribat is dated at 47.40 Ma, and the youngest at the 'la Teoulere' escarpment at 44.05 Ma. At least 89 otolith-based taxa are recorded, of which 69 are identified at species level. Twenty of these are introduced here by Lin, Nolf and Girone as new species: 'Elops' miiformis sp. nov., 'Ophichthus' mignolo sp. nov., Saurida trompensis sp. nov., 'Scopelarchus' gnocco sp. nov., 'Evermannella' razza sp. nov., Neoscopelus navicularis sp. nov., ' Trachyrincus' iocosus sp. nov., Nezumia teoulerensis sp. nov., 'Neobythites' auribatianus sp. nov., 'Neobythites' bozzolo sp. nov., 'Neobythites' leonardi sp. nov., Melamphaes acanthifer sp. nov., Zenion mattaccino sp. nov., Zenion vetustus sp. nov., 'Perca' lactarioides sp. nov., 'Perca' meiformis sp. nov., 'Liopropoma' sculpta sp. nov., 'Branchiostegus'' brevis sp. nov., 'Haemulon' strascinate sp. nov. and Cepola rostislavi sp. nov. The occurrence of N. teoulerensis sp. nov. is particularly important because it documents the earliest macrourid fossil record from the Northern Hemisphere. The assemblages all indicate a deep neritic environment, similar to that of several of the Ypresian and Priabonian deposits of the Aquitaine Basin. The difference in taxonomic composition between the Lutetian assemblages of Aquitaine and those of the neighbouring Anglo-Belgo-Parisian basin and Osteroden (Germany) is mainly environmentally based. The new material contains many nominal upper and/or lower Eocene species whose stratigraphical distribution is thus extended to the Lutetian, suggesting that the important faunal renewal in the Eocene of the Aquitaine Basin is more gradual than previously believed.