Scomberomorus undetermined

Scomberomorus sp. Fig. 25L–N Material examined UNITED STATES OF AMERICA – Mississippi • 175 isolated teeth; Catahoula Formation; SC 2013.28.565 to 28.571, SC 2013.28.572 (Fig. 25L–N), SC 2013.28.573 (2 teeth), SC 2013.28.574 (101 teeth), SC 2013.28.575 (50 teeth), SC 2013.28.576 (14 teeth). Description The teeth are broadly triangular, with larger specimens measuring 11 mm in apico-basal height and 7 mm in width (antero-posterior). The labial and lingual crown faces are convex, but the lingual face, particularly near the base, is more so. In anterior/posterior view, the crown is medially curved but may be straight (Fig. 25M). The anterior and posterior margins are formed into smooth, sharp, convex cutting edges, and in labial view these edges converge to a rounded apex. It appears that enameloid once covered the crown surface, but this is generally only preserved at the cutting edges of the teeth in our sample. In basal view, the tooth has a thin D-shaped outline, and the basal surface is flat to weakly concave (Fig. 25N). Remarks The teeth described above are similar to Sphyraena sp. non-laniary teeth (see above) but can be differentiated by their thicker crown that is asymmetrical in basal view (compare Fig. 25N to 25F). The lingual face of Scomberomorus sp. teeth is much more convex than the labial face, and the crown is more medially curved. In contrast, the Sphyraena sp. crown is thinner, straighter (in carinal view), and the labial and lingual crown faces are slightly but equally convex. The teeth of Scomberomorus sp. differ from those of? Acanthocybium sp. (see above) by their labio-lingually thinner crown (compare Fig. 25N to K) and primarily flat basal surface. Although two species of Scomberomorus have been identified from Eocene deposits in Alabama (see Ebersole et al. 2019), the teeth in our sample represent the first occurrence of this taxon within any Oligocene strata in the Gulf Coastal Plain of the USA.