Leptolepis macrocephalus ( Schroeder , 1956)

Schwarzhans, Werner & Keupp, Helmut, 2022, Early teleost otolith morphogenesis observed in the Jurassic of Franconia, Bavaria, southern Germany, Zitteliana 96, pp. 51-67 : 51

Leptolepis macrocephalus ( Schroeder, 1956)

Plate 3, figs 12-13

Otolithus macrocephali 1956 Otolithus macrocephali - Schröder: pl. 7, fig. 40.

Otolithus guttaeformis 1956 Otolithus guttaeformis - Schröder: pl. 6, figs 15-16.

Material.

3 specimens from Schröder’s collection from the early Callovian of Pünzendorf: holotype of Ot. macrocephalus (emended spelling, SNSB-BSPG 2022 III 1, Plate 3 , fig. 13), holotype of Ot. guttaeformis (SNSB-BSPG 2022 III 6, Plate 3 , fig. 12) and 1 paratype (SNSB-BSPG 2022 III 7).

Differential diagnosis.

Leptolepis macrocephalus differs from the coeval L. inaequalis in its more compressed shape, which is exhibited by a deeper ventral rim and a more expanded postdorsal rim and is expressed in the OL:OH ratio of 1.35-1.4 (vs. 1.5). It shares with L. inaequalis completely flat inner and outer faces, features that distinguish both species from all other known Leptolepis otoliths.

Discussion.

Leptolepis macrocephalus and L. inaequalis form a small group of otoliths with a special trait of having flat inner and outer faces. They occur during the Callovian and possibly the early Oxfordian. Their attribution to the genus is therefore less certain than that of Leptolepis otoliths from the Early Jurassic (see above).

Figures

Plate 3. Otoliths of Leptolepis kremmeldorfensis, L. inaequalis, L. macrocephalus, and Leptoelops rhenanus. figs 1 - 6: Leptolepis kremmeldorfensis (Schroeder, 1956); 1: holotype of Ot. kremmeldorfensis Schroeder, 1956 from Kremmeldorf (SNSB-BSPG 2022 III 35); 2: paratype of Ot. kremmeldorfensis Schroeder, 1956 from Kremmeldorf (SNSB-BSPG 2022 III 36); 3: holotype of Ot. amygdalinus Schroeder, 1956 from Kremmeldorf (SNSB-BSPG 2022 III 14); 4: paratype of Ot. bambergensis Schroeder, 1956 from Freiahorn (SNSB-BSPG 2022 III 10); 5: holotype of Ot. franconicus Schroeder, 1956 from Kremmeldorf (SNSB-BSPG 2022 III 24); 6: paratype of Ot. franconicus Schroeder, 1956 from Kremmeldorf (SNSB-BSPG 2022 III 27). figs 7, 8: Leptolepis cf. kremmeldorfensis (Schroeder, 1956), from the late Pliensbachian of Buttenheim, SNSB-BSPG 2022 IV 15. figs 9 - 11: Leptolepis inaequalis (Weiler, 1954); 9: holotype of Ot. puenzendorfensis Schroeder, 1956 from Puenzendorf (SNSB-BSPG 2022 III 39); 10: holotype of Ot. calloviensis Schroeder, 1956 from Puenzendorf (SNSB-BSPG 2022 III 8); 11: holotype of Ot. inaequalis Weiler, 1954 from the Callovian to Oxfordian of Kandern, Baden-Wuertemberg (SMF P. 3067). figs 12 - 13: Leptolepis macrocephalus (Schroeder, 1956); 12: holotype of Ot. guttaeformis Schroeder, 1956 from Puenzendorf (SNSB-BSPG 2022 III 6); 13: holotype of Ot. macrocephalus Schroeder, 1956 from Puenzendorf (SNSB-BSPG 2022 III 1). figs 14 - 16: Leptoelops rhenanus (Weiler, 1954); 14: holotype of Ot. rhenanus Weiler, 1954 from the Callovian of well Bruchsal D 205 (core from 482 to 487 m) near Weingarten, Baden-Wuerttemberg (SMF P. 2953); 15: holotype of Ot. rectisulcatus Schroeder, 1956 from Puenzendorf (SNSB-BSPG 2022 III 37); 16: holotype of Ot. scissus Schroeder, 1956 from Puenzendorf (SNSB-BSPG 2022 III 40).