Gobiidae, Cuvier, 1816

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 : 204

Gobiidae indet.

Fig. 70 O–P

Material examined

UNITED STATES OF AMERICA – Alabama • 1 otolith; MSC 39045 .

Description

Small otolith measuring 2.1 mm in length, roughly trapezoidal in shape. Inner face primarily smooth (except for depression at dorsal area), convex. Margins smooth, sharp in transversal view. Anterior margin ranging from almost straight to slightly incurved.Anterodorsal unevenly rounded. Dorsal margin only slightly rounded, subparallel with ventral margin. Posterodorsal is characterized by small rounded projection. Posterior incurved. Ventral margin almost straight, horizontal. Well-defined, divided sulcus slants slightly from posterodorsal to anteroventral. Ostium about twice as long and twice as wide as cauda. The ostium oval in shape, much more excavated than cauda. Ostium almost touches anterior margin. Posterior of cauda rounded. Ridge-like crista superior located above sulcus. Prominent, deeply depressed area in dorsal area touches crista superior. Crista inferior is small, ridge-like structure beneath cauda and posterior of ostium. Outer face smooth, convex, thickest at approximately center but thinning towards margins.

Remarks

The oldest known possible gobiid otolith occurred in middle Ypresian strata of India ( Nolf et al. 2006). Gobiid otoliths are quite rare in all known assemblages until the late Eocene. Nolf & Stringer (2003) noted 57 specimens of gobiids (“genus Gobiidarum ” vetustus) from the upper Eocene Yazoo Clay of Louisiana. We believe that the Lisbon Formation gobiid represents a different species from the Yazoo Clay taxon because of the significant differences between the shape of the otolith sulci, but a larger Lisbon sample is needed to corroborate our observation.

Stratigraphic and geographic range in Alabama

The single gobiid specimen was recovered from the “upper” Lisbon Formation at site ACh-7. Bartonian, zones NP16 and 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.