Lactarius amplus ( Pomerol, 1973 ) Stinton 1978

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 : 78

Lactarius amplus ( Pomerol, 1973) Stinton 1978

Fig. 28A–E

Lactarius amplus Pomerol, 1973: 122 , fig. 8 (figure without description).

Lactarius amplus – Stinton 1978: 181, pl. 12 figs 11–15. — Nolf 1985: 84. — Müller 1999: 152, fig. 32/6–11, pl. 16 fig. 17.— Ebersole et al. 2019: 207, fig. 71c–d. — Nolf 2013: 98, pl. 238.

Remarks

Lactarius was one of the most abundant otoliths in the collection. Two species were recognized, L. amplus and L. kokeni (see below), the latter one being more abundant. Both species can be easily separated by the shape of their otoliths: L. amplus has a horizontally more compressed outline (OL/OH = 1.15–1.33), whereas, in L. kokeni (OL/OH = 1.35–1.57), the posterior part of the otolith is markedly extended backwards.

Stratigraphic and geographic distribution

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

Figures

Fig. 28. Fish otoliths from the US middle and upper Eocene. A–E. Lactarius amplus Stinton, 1978, “Stone City beds”, Stone City Bluff, Brazos River, sample 2 from bed P, Texas (IRSNB P 10171– 10175). F–J. Lactarius kokeni (Dante & Frizzell, 1965), “Stone City beds”, Stone City Bluff, Brazos River, sample 2 from bed P, Texas (IRSNB P 10176–10180). 1 = ventral view; 2 = inner view. Scale bars = 1 mm.