Bregmaceros troelli Dante & Frizzell, 1965

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 : 45-47

Bregmaceros troelli Dante & Frizzell, 1965

Fig. 15A–D

Bregmaceros troelli Dante & Frizzell in Frizzell & Dante, 1965: 699, pl. 87 figs 14–19.

Bregmaceros troelli – Nolf 1985: 59; 2013: 56, pl. 87.

Bregmaceros sp. – Nolf & Stringer 2003: 5, pl. 3 fig. 18.

Remarks

Bregmaceros otoliths are sometimes tricky to identify at the species level ( Přikryl et al. 2016) due to their often insufficient diagnostic features. Several features, including an enlarged part in the antero-ventral area that forms a conspicuous sharp postero-ventral angle and an evident concavity in the dorsal rim, are very consistent in the investigated specimens, and therefore we have assigned them to B. troelli (or a closely related species complex). The species can be very abundant in some of the levels, such as the Landrum Member. In the upper sample of the Yazoo Clay in Louisiana, nearly 92% of the total assemblage was comprised of this species ( Nolf & Stringer 2003).

Stratigraphic and geographic distribution

Lutetian: Weches Formation and “Stone City beds”, Texas; Cane River Formation, Louisiana. Bartonian: Cook Mountain Formation, Texas and Mississippi; “upper” Lisbon Formation, Alabama; Moodys Branch Formation, Louisiana, Mississippi and Alabama. Priabonian: Yazoo Clay, Louisiana and Mississippi.

Figures

Fig. 15. Fish otoliths from the US middle and upper Eocene. A–D. Bregmaceros troelli (Dante & Frizzell, 1965). A–B. “Stone City beds”, Alabama Ferry on Trinity River, North, Texas (IRSNB P 10033–10034). C–D. Landrum M., Pin Oak Creek, Texas (IRSNB P 10035–10036). E–H. “Diretmus” serratus (Müller, 1999). E. “Stone City beds”, Stone City Bluff, Brazos River, sample 2 from bed P, Texas (IRSNB P 10037). F. “Stone City beds”, Alabama Ferry, on Trinity River, North, Texas (IRSNB P 10038). G–H. Wheelock M., Little Brazos River, Stenzel loc., Texas (IRSNB P 10039–10040). I–K. “Myripristis” cajun (Frizzell & Lamber, 1961). I. Wheelock M., Little Brazos River, Stenzel loc., Texas (IRSNB P 10041). J–K. “Stone City beds”, Stone City Bluff, Brazos River, Texas (IRSNB P 10042–10043). L–M. Carapus smithvillensis (Dante & Frizzell, 1965), “Stone City beds”, Alabama Ferry, on Trinity River, North, Texas (IRSNB P 10044–10045). 1 = ventral view; 2 = inner view. Scale bars = 1 mm.