Tippaha mythica, Schwarzhans and Stringer, 2020

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 : 16-18

TIPPAHA MYTHICA SCHWARZHANS AND STRINGER, 2020a

FIG. 8C

Material— eight specimens including three complete well-preserved specimens, specimen figured, DMNH 2021-09- 25 .

Description and Remarks—Tippaha mythica is certainly the most unique and impressive otolith in the Arkadelphia Formation assemblage based on its distinctive morphological characteristics. The basic outline is somewhat oblong to elliptic (sensu Smale et al. 1995), but there are numerous features that modify the shape. The convex inner face has a distinct and characteristic pseudobiostial sulcus that is primarily shallow except for a slightly deeper posterior portion of the cauda. An exceptional feature of the anterior portion of the cauda is the fading of its dorsal margin toward the moderately deep, well-marked, oval dorsal depression. There is no ventral furrow, but a long, obvious ventral depression is present under the sulcus. The most prominent feature is a long, fairly narrow predorsal projection that typically leans anteriorly at about 65– 750. The length of this conspicuous protuberance is often 25–30% of the length of the otolith. The outer face is usually irregular and nearly flat except for the massive predorsal protuberance.

Stringer et al. (2020) noted that T. mythica is probably the most distinct and remarkable otolith morphology presently known from the Cretaceous. In addition to the eight specimens from the Arkadelphia Formation, T. mythica is known from the Ripley Formation and the Owl Creek Formation, both Upper Cretaceous sites in northeastern Mississippi (Stringer et al. 2020) and the Providence Sand in Alabama, according to J. Ebersole, Director of Collections at McWane Science Center, Birmingham, Alabama (personal communication, 2020).

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.