Ekokenia eporrecta ( Koken, 1888 )

Lin, Chien-Hsiang & Nolf, Dirk, 2022, Middle and late Eocene fish otoliths from the eastern and southern USA, European Journal of Taxonomy 814, pp. 1-122 : 86-88

Ekokenia eporrecta ( Koken, 1888)

Fig. 32A–G

Otolithus (Sciaenidarum) eporrectus Koken, 1888: 282 , pl. 18 figs 16–17.

Ekokenia eporrecta – Frizzell & Dante 1965: 704, pl. 87 figs 11–12, 16, pl. 88 figs 5, 11.

“genus Sciaenidarum ” eporrectus – Nolf 1985: 88; 2003: 9, pl. 3 figs 6–9. — Müller 1999: 160, fig. 33/10–15.

Eokokenia eporrecta – Schwarzhans 1993: 27, fig. 11.

“ Sciaenida ” eporrecta — Nolf 2013: 107, pl. 281.

Ekokenia eporrecta – Ebersole et al. 2019: 217 , fig. 72e–f.

Remarks

The sulcus type of E. eporrecta might imply a close relationship with the family Haemulidae ; however, by having exclusive sciaenid features such as a strong postero-dorsal angle and constriction of the ostial cristae (particularly the ostial crista inferior), E. eporrecta can be confidently included in the Sciaenidae . The otoliths of E. eporrecta are the most abundant sciaenid species in the collection, and with the clear growth series of the species, it can easily be separated from those of other sciaenids by its short cauda and relatively flat inner face. A single, exceptionally large specimen ( Fig. 32A ) reveals a strong ontogenetic shift towards a much deeper ventral area and strongly convex inner face.

Stratigraphic and geographic distribution

Lutetian: Weches Formation and “Stone City beds”, Texas; Dobys Bluff Tongue of Kosciusko Formation, Mississippi; “lower” Lisbon Formation, Alabama; Piney Point Formation, Virginia. Bartonian: Cook Mountain Formation, Texas and Mississippi; “upper” Lisbon Formation, Alabama.

Figures

Fig. 32. Fish otoliths from the US middle and upper Eocene. A–G. Ekokenia eporrecta (Koken, 1888). A–B. Wheelock M., Little Brazos River, confluence with Brazos River, Texas (IRSNB P 10204–10205). C–G. “Stone City beds”, Stone City Bluff, Brazos River, sample 2, bed P, Texas (IRSNB P 10206– 10210). H–M. “Sciaena” claybornensis (Koken, 1888). H–K. Yazoo Clay, Copenhagen, Louisiana (IRSNB P 10211–10214). L–M. Moodys Branch F., Midway, Techeva Creek, Mississippi (IRSNB P 10215–10216). 1 = ventral view; 2 = inner view. Scale bars = 1 mm.