Eutawichthys

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 : 18

EUTAWICHTHYS SCHWARZHANS, HUDDLESTON, AND TAKEU-

CHI, 2018b

EUTAWICHTHYS MAASTRICHTIENSIS ( NOLF AND STRINGER, 1996)

FIG. 8D

Material— 21 specimens, specimen figured, DMNH 2021-09- 26 .

Description and Remarks— Eutawichthys maastrichtiensis has a nearly circular to slightly oval outline (sensu Smale et al. 1995). The dorsal margin is irregular, while the ventral margin can have crenulations that are often obliterated by erosion. The thin sagitta is only slightly convex with a distinctive, long sulcus (heterosulcoid type) that is wide and continuously curved. The cauda curves diagnostically dorsally in its posterior section. There is a depressed area that is fairly distinct above the center of the sulcus.

Eutawichthys maastrichtiensis was designated as an apogonid for many years, and there are certainly resemblances to the apogonids. Its designation as a berycid is discussed at length in Stringer et al. (2016) and is more congruent with molecular studies such as Betancur-R. et al. (2013) that indicate a much later divergence for the apogonids (around 45 Ma). The fossil-based genus Eutawichthys was erected by Schwarzhans et al. (2018b). Eutawichthys maastrichtiensis is known from several Cretaceous formations including the Severn Formation of Maryland ( Huddleston and Savoie 1983), the Woodbury Formation of New Jersey ( Stringer et al. 2016), the Eutaw Formation of Alabama ( Schwarzhans et al. 2018a), the Tar Heel Formation of North Carolina (Stringer et al. 2018), the Coon Creek Formation of Tennessee ( Stringer 2016b), the Ripley Formation of Mississippi (Stringer et al. 2020), and the Kemp Clay of Texas ( Schwarzhans and Stringer 2020a).

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.