Preophidion Frizzell & Dante, 1965

Lin, Chien-Hsiang & Nolf, Dirk, 2022, Middle and late Eocene fish otoliths from the eastern and southern USA, European Journal of Taxonomy 814, pp. 1-122 : 58

Genus Preophidion Frizzell & Dante, 1965

Remarks

Preophidion is an extinct genus with otoliths resembling those of the extant Sirembo . We here place P. elevatus ( Koken, 1888) , P. granus ( Müller, 1999) , and P. petropolis (Dante & Frizzell, 1965) in this genus. “ Neobythites ” meyeri and “ N.” stintoni were initially also assigned to Preophidion by Frizzell & Dante (1965), and this was followed as such in Ebersole et al. (2019), but here we reassign the former two species to the Symmetrosulcus (see above). The most significant distinctive feature between otoliths of Symmetrusulcus and Preophidion consists in the cleavage between the ostial and caudal collicula, which is vertical and short in otoliths of Symmetrosulcus , whereas it is more oblique and inclined in an anterodorsal-posteroventral direction in the more Sirembo -like otoliths of Preophidion . Additionally, Sirembo -like otoliths usually have a wider sulcus, a sharply restricted collum on the crista inferior, a more considerable thickness and a more convex inner face.