Protobythites brzobohatyi, SCHWARZHANS, 2010

Stringer, Gary L. & Sloan, James Carson, 2023, First Cretaceous teleostean otolith assemblage (Arkadelphia Formation, upper Maastrichtian) from Arkansas, USA, early Gadiformes, and the Western Interior Seaway, PaleoBios 40 (1994), pp. 1-39 : 19

PROTOBYTHITES BRZOBOHATYI SCHWARZHANS, 2010

FIG. 8H

Material— four specimens, specimen figured, DMNH 2021-09- 30 .

Description and Remarks— The four Arkadelphia Formation otoliths assigned to Protobythites brzobohatyi are similar to Ampheristus , but they are distinguished from Ampheristus in the inner face being distinctly convex in both the horizontal and vertical directions. Protobythites brzobohatyi also has a relatively smooth inner face except for the slightly deepened sulcus (especially the cauda). The sulcus has a wide, long ostium and a short, flexed, narrow cauda. There is a very shallow dorsal depression present and a faint ventral furrow on the inner face. The margins are sharp. Protobythites brzobohatyi has a thin appearance with a nearly flat outer face. The species was based on a single well-preserved otolith from the Maastrichtian of Bavaria ( Schwarzhans 2010). It is also known from the Maastrichtian Kemp Clay of Texas ( Schwarzhans and Stringer 2020a). Its occurrence is now extended to the Maastrichtian Arkadelphia Formation of Arkansas.

Figures

Figure 8. Otoliths from the Cretaceous Arkadelphia Formation. All specimens unless otherwise noted are inner views of right sagittae. Lapilli are macular views. Length in mm. A. Palaeogadus cf. P. weltoni Schwarzhans and Stringer (2020a), DMNH 2021-09- 23, 1.46 mm. B. Gadiformes indeterminate, DMNH 2021-09-24, 1.56 mm. C. Tippaha mythica Schwarzhans and Stringer (2020a), DMNH 2021-09-25, 3.85 mm. D. Eutawichthys maastrichtiensis Nolf and Stringer (1996), DMNH 2021-09-26, 3.93 mm. E. Eutawichthys zideki Nolf and Stringer (1996), DMNH 2021-09-27, 1.42 mm. F.Eutawichthys cf. E. stringeri Schwarzhans, Huddleston, and Takeuchi (2018b), DMNH 2021-09-28, 1.85 mm. G. Ampheristus cf. A. americanus Schwarzhans and Stringer (2020a), DMNH 2021-09-29, 1.58 mm. H. Protobythities brzobohatyi Schwarzhans (2010), DMNH 2021-09-30, 1.68 mm. I. Lapillus type 1, DMNH 2021-09-31, 2.98 mm.