Preophidion meyeri ( Koken, 1888 )

Ebersole, Jun A., Cicimurri, David J. & Stringer, Gary L., 2019, Taxonomy and biostratigraphy of the elasmobranchs and bony fishes (Chondrichthyes and Osteichthyes) of the lower-to-middle Eocene (Ypresian to Bartonian) Claiborne Group in Alabama, USA, including an analysis of otoliths, European Journal of Taxonomy 585, pp. 1-274 : 197-198

Preophidion meyeri ( Koken, 1888)

Fig. 70 C–D

Otolithus (Gadidarum) meyeri Koken, 1888: 289–290 , pl. 18, figs 8–9.

Otolithus (Gadidarum) meyeri – Campbell 1929a: 272–273 , pl. 29, figs 8–9.

Preophidion meyeri – Frizzell & Dante 1965: 713 , 715.

“genus Lepophidiinorum ” meyeri – Nolf 1980: 111 , pl. 18, fig. 16; 1985: 66, fig. 51o.

Symmetrosulcus meyeri – Schwarzhans 1981: 75 , 78, pl. 20.

“genus Neobythitinarum ” meyeri – Breard & Stringer 1995: 80 . — Müller 1999: 126. — Nolf 2003: 5, pl. 1, fig. 9. — Nolf & Stringer 2003: 4–5, pl. 3, figs 3–10.

“ Neobythitina ” meyeri – Nolf 2013: 68 , pl. 125.

Material examined

UNITED STATES OF AMERICA – Alabama • 131 otoliths; MSC 7303.1 , MSC 7303.2 , MSC 7303.4 , MSC 7303.5 , MSC 35076.2 , MSC 37236.1 , MSC 37236, MSC 39055, GLS otolith comparative collection (104 specimens), WSU CC 466.1 , WSU CC 466.2 , WSU CC 466.3 , WSU CC 466.4 , WSU CC 467.1 , WSU CC 467.2 , WSU CC 467.3 , WSU CC 467.4 , WSU CC 468.1 , WSU CC 468.2 , WSU CC 468.3 , WSU CC 468.4 , WSU CC 469.1 , WSU CC 469.2 , WSU CC 469.3 , WSU CC 476.1 , WSU CC 476.2 , WSU CC 476.3 , WSU CC 476.4 .

Description

Sagittae biconvex, with oblong to elliptic shape (sensu Smale et al. 1995); height/length ratio from approximately 44–53%. Inner face smooth, convex. Adult specimens of small to medium size (rarely exceeding 6 mm). Margins of adult and juvenile specimens smooth. Anterior margin bluntly pointed, anterodorsal margin long, slightly arched. Dorsal margin short, almost horizontal. Posterodorsal margin very slightly arched, longer than anterodorsal margin. Posterior margin thinly pointed. Ventral margin evenly and broadly rounded. Lightly impressed, distinct sulcus located on inner face. Sulcus divided, completely enclosed, marked by incised lines. Ostium is about equal in length to cauda. Sides of ostium nearly parallel. Anterior end of ostium sharply pointed, almost touches anterodorsal margin. Ostium filled with colliculum, not excavated. Slight ventral constriction of ostium near junction (incised line) with cauda. Cauda is approximately same width as ostium. Sides of cauda nearly parallel but for slight ventral constriction near intersection with the ostium. Cauda/ostium intersection marked by thin, slightly inclined, incised line. The cauda filled with colliculum, not excavated. Posterior end of cauda bluntly rounded, separated from posterior margin by distinct, narrow border. Shallow, elongated, irregular depressed area centered above sulcus. Crista superior weakly developed; crista inferior lacking or very weakly developed. Ventral furrow usually absent. Outer face convex, dorsal portion more strongly convex. Outer face strongly sculptured to undulating. Rounded anterodorsal dome visible.

Remarks

This extinct species of cusk-eel was widely distributed and quite abundant within the US Gulf Coast during the Eocene. It has been reported from Alabama, Georgia, Louisiana, Mississippi, and Texas ( Frizzell & Dante 1965; Breard & Stringer 1995; Stringer & Miller 2001; Green & Stringer 2002; Nolf & Stringer 2003; Stringer et al. 2013). In Alabama, P. meyeri is the only species known from all three of the Claiborne Group formations, and it is the most abundant species we encountered. At one Lisbon Formation site, the species represents almost 50% of the total otolith specimens in the sample.

Stratigraphic and geographic range in Alabama

Specimens were recovered from the lower Tallahatta Formation at site ADl-1, the “upper” Lisbon Formation at site ACh-8, and the Gosport Sand at site ACl-4. Upper Ypresian to middle Bartonian, zones NP14 to NP17.

Figures

Fig. 70. Claiborne Group, “upper” Lisbon Formation, otoliths. A–B. Diretmus? cf. D. serratus (Müller, 1999), MSC 42212. A. Inner face (left sagitta). B. Anterior view. — C–D. Preophidion meyeri (Koken, 1888), MSC 39055. C. Inner face (right sagitta). D. Dorsal view. — E–F. Preophidion cf. P. petropolis Frizzell & Dante, 1965, MSC 42193. E. Inner face (right sagitta). F. Dorsal view. — G–H. Signata stenzeli Frizzell & Dante, 1965, MSC 39051. G. Inner face (left sagitta). H. Dorsal view. — I–J. Signata nicoli Frizzell & Dante, 1965, MSC 39046. I. Inner face (left sagitta). J. Dorsal view. — K–L. Hoplobrotula melrosensis (Frizzell & Dante, 1965), MSC 37059.3. K. Inner face (right sagitta). L. Dorsal view. — M–N. Lepophidium? mucronata (Koken, 1888), MSC 39054. M. Inner face (left sagitta). N. Dorsal view. — O–P. Gobiidae Cuvier, 1816, indet. MSC 39045. O. Inner face (left sagitta). P. Dorsal view. — Q–R. Bothidae Smitt, 1892, indet. MSC 42235. Q. Inner face (right sagitta). R. Dorsal view. Scale bars: A–P= 2 mm; Q–R =1 mm.