Sciaena? pseudoradians (Dante & Frizzell in Frizzell & Dante, 1965 )

Cicimurri, David J., Ebersole, Jun A., Stringer, Gary L., Starnes, James E. & Phillips, George E., 2025, Late Oligocene fishes (Chondrichthyes and Osteichthyes) from the Catahoula Formation in Wayne County, Mississippi, USA, European Journal of Taxonomy 984 (1), pp. 1-131 : 92-93

Sciaena? pseudoradians (Dante & Frizzell in Frizzell & Dante, 1965)

Fig. 26X –AA

Corvina pseudoradians Dante & Frizzel in Frizzell & Dante, 1965: 707–708.

Material examined

UNITED STATES OF AMERICA – Mississippi • 134 sagittae; Catahoula Formation ; MMNS VP-7445 ( Fig. 26X–Y ), MMNS VP-7446 (3 specimens), MMNS VP-7448 (3 specimens), MMNS VP-7451 , MMNS VP-7453 (4 specimens), MMNS VP-7459.2 , MMNS VP-7460.1 , MMNS VP-8200.1 (9 specimens), MMNS VP-8711 (4 specimens), MMNS VP-8711.1 ( Fig. 26Z –AA), MMNS VP-8935 , SC 2013.28.757 , SC 2013.28.758 , SC 2013.28.762 , SC 2013.28.764 to 28.770 , SC 2013.28.772 , SC 2013.28.774 to 28.776 , SC 2013.28.778 , SC 2013.28.781 to 28.783 , SC 2013.28.786 , SC 2013.28.794 , SC 2013.28.801 , GLS otolith comparative collection (84 specimens) .

Description

The outline of Sciaena? pseudoradians is primarily rectangular (sensu Smale et al. 1995), but the anterior and ventral margins are somewhat convex and rounded. The margins are typically smooth, and the inner face is moderately convex. The inner face is characterized by a very large, prominent heterosulcoid-type sulcus. The ostium is exceptionally large in length and height, especially compared to the cauda. The ostium extends from near the anterodorsal margin well down into the ventral field and is largest at the posterior portion. The posteroventral portion of the ostium extends noticeably underneath the cauda in larger specimens. The height of the cauda is only about 25% of the height of the ostium (i.e., much narrower in comparison). The cauda has a distinctive horizontal and downturned component. The horizontal portion appears to shorten in length compared to the downturned portion during ontogenetic development ( Nolf 2003: pl. 2 figs 3–6). The outer face increases in irregularity with growth and is convex, but not as much as the inner face.

Remarks

Dante & Frizzell in Frizzell & Dante (1965) first named Sciaena? pseudoradians as Corvina pseudoradians based on specimens from the Byram Formation (Oligocene, Rupelian) in Mississippi, USA, and the holotype (USNM 23368) was illustrated by Nolf (2003: fig. 6). Sciaena? pseudoradians is known from numerous Oligocene formations in Mississippi, Louisiana, and Alabama ( Nolf 2003; Stringer & Worley 2003; Worley 2004; Stringer et al. 2020c; Ebersole et al. 2021), and its presence is therefore not unexpected in the Catahoula Formation. Sciaena? pseudoradians is the most abundant otolith-based species in our Catahoula Formation sample (n = 134), including seven additional specimens tentatively assigned to the species. Nolf & Stringer (2003) identified Sciaena ? aff. pseudoradians from the upper Eocene (primarily Priabonian) Yazoo Clay based on 78 specimens of the 5293 otoliths they examined (1.47% of the sample). Sciaena aff. pseudoradians was reported from the Eocene Clinchfield Formation in Georgia, where it represented 8% of the total number of specimens in the bulk sample. Lin & Nolf (2022) noted that S.? pseudoradians is known primarily from the lower Oligocene of the Gulf Coastal Plain, but they also noted that “imperfectly preserved” otoliths are known from the Eocene of Texas and Louisiana (Bartonian and Priabonian).

Figures

Fig. 26 (page 88). Allomorone sp. (A–B), Lutjanidae gen. et sp. indet. (C–I), Aplodinotus distortus Nolf, 2003 (J–M), A. gemma (Koken, 1888) (N–S), Sciaenidae gen. et sp. indet. (T–W), Sciaena? pseudoradians (Dante & Frizzell in Frizzell & Dante, 1965) (X–AA), and Sciaena? radians (Koken, 1888) (BB–CC), remains. A–B. MMNS VP-12160, Allomorone sp., left otolith (reversed). A. Inner view. B. Dorsal view. C–D. MMNS VP-7685.1, Lutjanidae gen. et sp. indet., tooth. C. Profile view. D. Basal view. E–F. MMNS VP-7685.2, Lutjanidae gen. et sp. indet., tooth. E. Profile view. F. Basal view. G–I. MMNS VP-8341, Lutjanidae gen. et sp. indet., left dentary. G. Labial view. H. Oral view. I. Lingual. J–K. MMNS VP-7458.1, Aplodinotus distortus, left otolith (reversed). J. Dorsal view. K. Inner view. L–M. MMNS VP-7456.1, A. distortus, left otolith (reversed). L. Inner view. M. Dorsal view. N–O. MMNS VP-8712.2, A. gemma, right otolith. N. Inner view. O. Dorsal view. P–Q. MMNS VP-8430.1, A. gemma, right otolith. P. Inner view. Q. Dorsal view. R–S. MMNS VP-8430.2, A. gemma, left otolith (reversed). R. Inner view. S. Dorsal view. T–U. MMNS VP-8712.3, Sciaenidae gen. et sp. indet., left otolith (reversed).T. Inner view.U. Dorsal view.V–W. MMNS VP-8712.4, Sciaenidae gen. et sp. indet., right otolith. V. Inner view. W. Dorsal view. X–Y. MMNS VP-7445, Sciaena? pseudoradians, left otolith (reversed). X. Inner view. Y. Dorsal view. Z–AA. MMNS VP-8711.1, S.? pseudoradians, left otolith (reversed). Z. Inner view. AA. Dorsal view. BB–CC. MMNS VP-12076, Sciaena? radians, left otolith (reversed). BB. Inner view. CC. Dorsal view. Scale bars: A–B, N–O, T–U, BB–CC = 1 mm; C–D, P–Q, X–Y = 5 mm; E–F, R–S = 4 mm; G–I = 2 cm; J–M, V–W = 3 mm; Z–AA = 2 mm.