Bregmaceros, Thompson, 1840

Lin, Chien-Hsiang, Brzobohatý, Rostislav, Nolf, Dirk & Girone, Angela, 2017, Tortonian teleost otoliths from northern Italy: taxonomic synthesis and stratigraphic significance, European Journal of Taxonomy 322, pp. 1-44 : 21

Bregmaceros sp.

Bregmaceros Thompson, 1840 has small and thin otoliths which are easily recognised, but their identification at species level is problematic, because specific features mainly concern the overall shape of the outline and the protruding denticles, which are often not well-preserved in the fossil material. Therefore, the identification of fossil specimens in this group is delicate and requires sufficient specimens ( Přikryl et al. 2016). Our Bregmaceros otoliths ( Fig. 7 M–O) are characterised by a very large, wide and triangular antero-ventral lobe, and this key feature is different from that of Bregmaceros albyi (Sauvage, 1880) , a more common species reported from the Tortonian of northern Italy (e.g., Anfossi & Mosna 1969a, as Bregmaceros catulus ). The shape of our Bregmaceros otoliths is actually more similar to that of Bregmaceros deklaszi Schwarzhans, 2013 (and Bregmaceros hybridus Schwarzhans, 2013 , which may just reflect aspects of the variability of B. deklaszi , based on the iconographies) (see Schwarzhans 2013b: pl. 5, figs 19–26, 11–18, respectively), reported from the middle–late Miocene boundary of West Africa. But, again, the characteristic antero-ventral lobe of our specimens is still markedly larger than that of the West African species. In fact, these Tortonian otoliths do not match any of the currently known fossil species from the Mediterranean or Central Paratethys ( Nolf 2013: pls 86–87; Přikryl et al. 2016), but, lacking sufficient material, we prefer to keep these specimens in open nomenclature.

Figures

Fig. 7. Tortonian fish otoliths from northern Italy. A. Scopelopsis pliocenicus (Anfossi & Mosna, 1976), Sant’Agata Fossili (IRSNB P 9754). B–C. Myctophum coppa Girone, Nolf & Cavallo, 2010, Sant’Agata Fossili (IRSNB P 9755–P 9756). D. Myctophum fitchi (Schwarzhans, 1979), Torrente Stirone (IRSNB P 9757). E–F. Notoscopelus bolini Nafpaktitis, 1975, Torrente Stirone (IRSNB P 9760– P 9761). G–H. Myctophum punctatum Rafinesque,1810, Sant’Agata Fossili (IRSNB P 9758–P 9759). I. Notoscopelus aff. caudispinosus (Johnson, 1863), Mondovi, Madonna della Neve (IRSNB P 9764). J–K. Notoscopelus elongatus (Costa, 1844), Costa Vescovato (IRSNB P 9762–P 9763). L. Notoscopelus resplendens (Richardson, 1845), Gallo D’Alba (IRSNB P 9765). M–O. Bregmaceros sp., Sant’Agata Fossili (IRSNB P 9766–P 9768). P. Bathygadus novus (Bassoli, 1906), Sant’Agata Fossili (IRSNB P 9769). Q. Coelorinchus arthaberi (Schubert, 1905), Montegibbio (IRSNB P 9770). R. Trachyrincus scabrus (Rafinesque, 1810), Montegibbio (IRSNB P 9771). 1 = ventral view; 2 = inner view. Scale bars = 1 mm.