ALBULIDAE INDETERMINATE

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 : 6

ALBULIDAE INDETERMINATE

FIG. 5B

Material— four small, eroded specimens, specimen figured, DMNH 2021-09-02 ( Fig. 5B ) .

Description and Remarks— These specimens were assigned to Albulidae indeterminate . They are believed to be closely related to the genus Albula , but this determination cannot be made with the existing specimens. The Arkadelphia Formation Albulidae indeterminate are very similar to the Albulidae indeterminate illustrated in Stringer et al. (2020, fig. 4I–J) from the Ripley Formation in northeastern Mississippi. The otoliths are oval in shape (sensu Smale et al. 1995) and somewhat elongate (H/L ratios of around 50%). The margins are mainly smooth. The strongly convex inner face has a sulcus that is located primarily supramedially and opens onto the anterodorsal margin. It is difficult to discern the ostium and cauda juncture, but the cauda bends ventrally near its posterior. There is a wide, smooth ventral area with no ventral furrow. The outer face is essentially flat to slightly concave. The Arkadelphia Formation specimens appear to be different from Albula cf. A. bashiana ( Frizzell, 1965a) reported from the Kemp Clay of Texas by Schwarzhans and Stringer (2020a) in respect to the outline, depth of the cauda, and the down-turned portion of the cauda. The exact taxonomic position and relationship of this albulid is not known presently.

Figures

Figure 5. Otoliths from the Cretaceous Arkadelphia Formation. All specimens unless otherwise noted are inner views of right sagittae. Length in mm. A. Elops sp., DMNH 2021-09-01, 1.89 mm. B. Albuliformes indeterminate, DMNH 2021-09-02, 1.42 mm. C. Elopothrissus sp. DMNH 2021-09-03, 1.83 mm. D. Genartina sp. DMNH 2021-09-04, 0.85 mm. E. Osmeroides sp. DMNH 2021-09-05, 3.85 mm. F. Anguilla? chickasawae Schwarzhans and Stringer (2020b), DMNH 2021-09-6, 1.90 mm. G. Echiophis aff. E. semisphaeroides Schwarzhans (2003), DMNH 2021-09-07, 3.25 mm. H. Muraenanguilla? sp. DMNH 2021-09-08, 2.18 mm.