Myripristis, Cuvier, 1829

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 : 194

Myripristis sp.

Fig. 69 Q–R

Weileria cajun – Frizzell & Lamber 1961: 20 , figs 6, 18–19.

Myripristis creola – Stringer 1977: 88–91 , pl. 1, fig. 1; 1986: 215.

Myripristis sp. – Stringer & Breard 1997: 565. — Breard & Stringer 1999: 135.

“genus Myripristidarum ” cajun – Nolf & Stringer 2003: 4 , pl. 4, figs 1a–2b.

“ Myripristina ” cajun – Nolf 2013: 80 , pl. 172.

Material examined

UNITED STATES OF AMERICA – Alabama • 2 otoliths; GLS otolith comparative collection (1 specimen), MSC 39047 .

Description

Two ablated specimens indicate Myripristis . Sagittae distinct in having scutiform shape; greatest length across the dorsal margin. Height/length ratios around 70-75%. Some margins appear coarsely crenulated. Dorsal margin is almost straight; indications of dorsal and posterodorsal domes. Posteroventral margin slants inward, almost straight down to ventral margin. Ventral margin very short, broadly and evenly rounded. Anteroventral margin slants almost straight down from dorsal margin to ventral margin. Inner face slightly convex, marked by conspicuous dorsal sulcus. Sulcus located almost entirely on dorsal margin. Sulcus consists of ostium, anterior cauda, and posterior cauda. Sulcus unevenly excavated, filled with colliculum. Ostium about one-half length of cauda; ostium appears subelliptical in shape. Anterior and posterior cauda areas of approximately equal length. Prominent caudal keel. Anterior part of cauda is filled with colliculum; posterior part of cauda deeply excavated, little colliculum. Outer face irregularly convex, sculptured. Posterior of outer face of many specimens marked by linear pustules merging into incised radial lines.

Remarks

The sulcus of the otoliths, consisting of an ostium and anterior and posterior cauda, is a specialized myripristid feature ( Frizzell & Lamber 1961). The Myripristis sp. otoliths from the Lisbon Formation in Alabama are very similar to middle and late Eocene otoliths found in Louisiana, Mississippi, and Texas ( Stringer 1986, 2016; Breard & Stringer 1995, 1999; Stringer & Breard 1997; Nolf & Stringer 2003).

Stratigraphic and geographic range in Alabama

The two Myripristis sp. specimens were recovered from the “upper” Lisbon Formation at site ACh-7. Bartonian, zones NP16 and NP17.

Figures

Fig. 69. Claiborne Group, “upper” Lisbon Formation, otoliths. A–B. Albula sp., MSC 562. A. Inner face (right sagitta). B. Dorsal view. — C–D. Pythonicthys colei (Müller, 1999), WSU CC 474. C. Inner face (left sagitta). D. Dorsal view. — E–F. Muraenesocidae Kaup, 1859, indet., MSC 39064. E. Inner face (left sagitta). F. Dorsal view. — G–H. Ariosoma nonsector Nolf & Stringer, 2003, MSC 39069. G. Inner face (left sagitta). H. Dorsal view. — I–J. Paraconger sector (Koken, 1888), MSC 39052. I. Inner face (right sagitta, broken on anterodorsal angle). J. Dorsal view. — K–L. Pseudophichthys sp., MSC 37059.2. K. Inner face (right sagitta). L. Dorsal view. — M–N. Rhynchoconger sp., MSC 37059.6. M. Inner face (left sagitta). N. Dorsal view. — O–P. Gnathophis meridies (Frizzell & Lamber, 1962), MSC 37059.XX. O. Inner face (right sagitta). P. Dorsal view. — Q–R. Myripristis sp., MSC 39047. Q. Inner face (right sagitta). R. Dorsal view. Scale bars: A–B =5 mm; C–R =2 mm.