Elops undetermined

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

ELOPS SP.

FIG. 5A

Material— one small, broken specimen, DMNH 2021- 09-01.

Description and Remarks— Although the single, small specimen (2.5 mm) attributed to Elops from the Arkadelphia Formation is broken (the anterior portion is missing), there are enough characteristics to assign it to this genus. The overall shape is oval (sensu Smale et al. 1995). The dorsal margin is somewhat rounded, while the ventral margin is more broadly and evenly rounded. The inner face is convex. Only a very small portion of the ostium is present, while the cauda is complete. The cauda is fairly wide and has an arching of its dorsal margin near the center. However, the posterior portion of the cauda is slightly downturned. The terminal portion of the cauda is rounded. There is no dorsal depression. The ventral furrow is faint and close to the ventral margin. The outer face is almost flat.

The Arkadelphia Formation specimen shows characteristics comparable to Elops eutawanus Schwarzhans, Huddleston, and Takeuki (2018b) from the Cretaceous (Santonian) of Alabama. Like the Arkadelphia Formation specimen attributed to Elops , the specimen of Elops eutawanus is broken anteriorly ( Schwarzhans et al. 2018b, figs. 2D–G). The Arkadelphia Formation Elops otolith, especially the cauda and features of the inner face, is similar to the extant Elops from the eastern Atlantic off the coast of central Africa ( Nolf 2013, Froese and Pauly 2019).

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.