Gnathophis meridies ( Frizzell & Lamber, 1962 )

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 : 192-193

Gnathophis meridies ( Frizzell & Lamber, 1962)

Fig. 69 O–P

“ Conger ” meridies Frizzell & Lamber, 1962 : figs 2a–b, 11a–d.

Paraconger meridies – Nolf 1985: 43 .

Gnathophis meridies – Nolf 2013 : pl. 22.

Material examined

UNITED STATES OF AMERICA – Alabama • 4 otoliths; GLS otolith comparative collection (3 specimens), MSC 37059 .

Description

Outline primarily oval with noticeable angularity. Length of sagitta is greater than height; height/ length ratios from approximately 60–72%. Margins smooth except for few small lobes on posterodorsal and posteroventral. Anterodorsal margin nearly straight; remaining dorsal and posterodorsal margins rounded.Anteroventral margin only slightly rounded; middle portion of ventral margin almost horizontal. Posteroventral margin rounded. Anterior more tapered than posterior. Prominent sulcus on inner face slants at approximately 45-degrees. Sulcus extends across approximately 75% of inner face. Dorsal and ventral margins of sulcus essentially parallel. Sulcus undivided, no defined ostium and cauda. Ostium does not quite reach anterior margin. Short, fairly wide ostial channel opens onto anterodorsal margin. Posterior of sulcus rounded. No depressed area above sulcus. Crista superior more pronounced than crista inferior. No ventral furrow. Outer face usually convex, thickest at center.

Remarks

Gnathophis meridies is an uncommon component at its type stratum and locality, the lower Eocene Bashi Formation (Wilcox Group) in Meridian, Mississippi. This taxon is also uncommon in the Claiborne Group in Alabama. Species of Gnathophis lack a depressed area above the sulcus, a feature that occurs on most congrid otoliths. Although one of the specimens we examined is a juvenile and two specimens are fairly worn, they possess the salient characteristics indicative of Gnathophis meridies .

Stratigraphic and geographic range in Alabama

Gnathophis meridies is known only from the “upper” Lisbon Formation at site ACh-7. Bartonian, zones NP16 and NP17.

Figures

Fig. 69. Claiborne Group, “upper” Lisbon Formation, otoliths. A–B. Albula sp., MSC 562. A. Inner face (right sagitta). B. Dorsal view. — C–D. Pythonicthys colei (Müller, 1999), WSU CC 474. C. Inner face (left sagitta). D. Dorsal view. — E–F. Muraenesocidae Kaup, 1859, indet., MSC 39064. E. Inner face (left sagitta). F. Dorsal view. — G–H. Ariosoma nonsector Nolf & Stringer, 2003, MSC 39069. G. Inner face (left sagitta). H. Dorsal view. — I–J. Paraconger sector (Koken, 1888), MSC 39052. I. Inner face (right sagitta, broken on anterodorsal angle). J. Dorsal view. — K–L. Pseudophichthys sp., MSC 37059.2. K. Inner face (right sagitta). L. Dorsal view. — M–N. Rhynchoconger sp., MSC 37059.6. M. Inner face (left sagitta). N. Dorsal view. — O–P. Gnathophis meridies (Frizzell & Lamber, 1962), MSC 37059.XX. O. Inner face (right sagitta). P. Dorsal view. — Q–R. Myripristis sp., MSC 39047. Q. Inner face (right sagitta). R. Dorsal view. Scale bars: A–B =5 mm; C–R =2 mm.