Hoplostethus Cuvier, 1829

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 : 26

Genus Hoplostethus Cuvier, 1829

Description

A large, adult otolith ( Fig. 10F ) of Hoplostethus lawleyi Koken, 1891 is easily distinguished from the Miocene Hoplostethus praemediterraneus Schubert, 1905 ( Fig. 10 A–E) by its very depressed anterodorsal area. This feature also characterises large-sized otoliths of the extant Hoplostethus mediterraneus Cuvier, 1829 , but otoliths of H. lawleyi are different from those of H. mediterraneus in having a wider sulcus, a strongly developed ostial colliculum and a narrower ventral area. The distinction between H. mediterraneus and H. praemediterraneus can be made with the help of the growth series of H. praemediterraneus from the Badenian of the Carpathian Foredeep (Brzobohatý 1978: pl. 1, figs 1–16, as Hoplostethus levis biexcissus and H. l. levis ) and of our material ( Fig. 10 A–E), which clearly demonstrate that the otoliths of H. praemediterraneus are, at each stage, higher and more compact in shape than those of H. mediterraneus (see Nolf 2013: pl. 165).

Figures

Fig. 10. Tortonian fish otoliths from northern Italy. A–E. Hoplostethus praemediterraneus Schubert, 1905; A–B. Montegibbio, C–E. Sant’Agata Fossili (IRSNB P 9804–P 9808). F. Hoplostethus lawleyi Koken, 1891, Sant’Agata Fossili (IRSNB P 9809). G. Parascombrops mutinensis (Bassoli, 1906), Torrente Stirone (IRSNB P 9810). H. “Haemulon” lucidum (Bassoli, 1906), Montegibbio (IRSNB P 9811). I. Pomadasys cf. incisus (Bowdich, 1825), Sant’Agata Fossili (IRSNB P 9812). J. Epigonus constanciae (Giglioli, 1880),Torrente Stirone(IRSNB P 9813). K. Gerreidaeindet., Montegibbio(IRSNB P 9814). L. Cepola macrophthalma (Linnaeus, 1758), Torrente Stirone (IRSNB P 9815). M. Epigonus italicus (Bassoli, 1906), Montegibbio (IRSNB P 9816). N. Dentex aff. maroccanus Valenciennes, 1830, Sant’Agata Fossili (IRSNB P 9817). O–Q. Owstonia neogenica (Nolf & Cappetta, 1989), Torrente Stirone (IRSNB P 9818–P 9820). 1 = ventral view; 2 = inner view; 3 = anterior view. Scale bars = 1 mm.