Anoxypristis undetermined

Anoxypristis sp. Fig. 13S–X Material examined UNITED STATES OF AMERICA – Mississippi • 10 rostral spines; Catahoula Formation; MMNS VP-12071 (Fig. 13S–U), MMNS VP-12072 (7 specimens), MMNS VP-12072.1 (Fig. 13V–X), SC 2013.28.514. Description The spines are elongated, very thin dorso-ventrally (Fig. 13T, W), with a triangular dorsal outline. The anterior and posterior faces are thin and converge distally to form a medially located point (Fig. 13U, X). The basal surface may have an elliptical or teardrop-shaped (rounded anterior margin but tapering posteriorly) outline (Fig. 13S, V). Remarks These spines are comparable to those occurring on a rostrum of extant Anoxypristis sp. that we examined (SC 86.214.1). They differ from the spines of the Catahoula Formation Pristis sp. (see above) and those of extant Pristis (i.e., MSC 43849, MSC 43850, SC 90.80.1) by being much thinner dorso-ventrally (although Pristis spines are very thin at the pointed distal end), having rather thin anterior and posterior faces, and having an elliptical to teardrop-shaped basal outline. In contrast, the fossil Pristis sp. spines are comparably thicker, very elongated but narrow antero-posteriorly, the posterior surface is concave, and the basal outline is “D” shaped. Although Cicimurri & Knight (2009) observed an Anoxypristis sp. rostral spine from the Chandler Bridge Formation (Chattian, NP25) of South Carolina that was housed in a private collection, sawfish specimens have yet to be formally described from the South Carolina Oligocene. Anoxypristis spines of similar morphology to those from the Catahoula Formation have been confirmed from middle Eocene deposits in Alabama (Cappetta & Case 2016; Ebersole et al. 2019), but we cannot determine whether they are conspecific.