Sparus? cf. elegantulus ( Koken, 1888 ), 1758

Sparus? cf. elegantulus ( Koken, 1888) View in CoL

Fig. 29A–B View Fig

Otolithus (Pagelli) elegantulus Koken, 1888: 279 .

Material examined

UNITED STATES OF AMERICA – Mississippi • 1 sagitta; Catahoula Formation ; MMNS VP-12077 .

Description

The outline of MMNS VP-12077 is essentially a square. The margins are primarily irregular with varying indications of lobation, sinuosity, and smoothness. The height/length ratio is about 0.65. The inner face tends to be slightly and fairly evenly convex ( Fig. 29B View Fig ). A prominent heterosulcoid-type sulcus extends across approximately 85% of the inner face ( Fig. 29A View Fig ). The sulcus, which is located slightly dorsal, is essentially horizontal except for a very small, downwardly flexed posterior of the cauda. The ostium opens on the anterior margin. The dorsal and ventral margins of the ostium are approximately parallel. The posteroventral portion of the ostium does not extend underneath the cauda. The ostium is approximately 40% of the length of the cauda. The height of the cauda is approximately 50–60% of the height of the ostium. Approximately 80% of the cauda is horizontal with about 20% downturned. The downturned portion is approximately 45° from horizontal. There is an irregularly shaped, dorsal depression above the cauda and a faint ventral furrow located away from the ventral margin. The outer face is slightly concave and may be slightly irregular.

Remarks

The single specimen was tentatively assigned to Sparus elegantulus due to its preservation. The species was originally identified by Koken (1888) in the Gulf Coast Plain of the USA. Sparus? elegantulus is known from the Eocene of Alabama, Georgia, Louisiana, and Mississippi ( Nolf & Stringer 2003; Nolf 2013; Stringer et al. 2022a). Within Oligocene deposits, the species has previously been reported from the Rupelian Glendon Limestone (NP22/23) in Mississippi ( Stringer et al. 2020c) and from the Glendon Limestone Member of the Byram Formation (NP23) of Alabama by Ebersole et al. (2021). In the latter occurrence, the species was relatively abundant and represented 12.06% of the total otolith sample.