Gen. et sp, Rafinesque, 1810

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 : 180

Gen. et sp . indet.

Fig. 66 M–U

Ostracion sp. – White 1956: 146.

Ostracion meretrix – Case 1981: 2 , fig. 22.

Ostracion sp. – Thurmond & Jones 1981: 108.

Material examined

UNITED STATES OF AMERICA – Alabama • 12 isolated teeth; Claiborne Group; MMNS VP-8194, MSC 2401, MSC 35771.1–3, MSC 37121, MSC 37136, MSC 37418, NJSM 24046, NJSM 24327, WSU 28, WSU 5005.

Description

Dermal plates generally polygonal, thickest at center but laterally tapered. Outer surface convex, ornamented with concentric pattern of isolated enameloid-covered tubercles surrounding central node. Internal surface smooth, concave.

Remarks

In North America, fossil dermal plates like those described above have been assigned to Ostracion Rafinesque, 1815 (see Leriche 1942; White 1956; Stringer 2001). However, as discussed by Winterbottom & Tyler (1983), Tyler & Gregorova (1991), and Weems (1998, 1999), there is a tremendous amount of inter- and intraspecific variation within the dermal armor of ostraciid fish, and even on the body of a single individual. Weems (1998) explained that specimens like those described herein can be assigned to the Ostraciidae because those of Aracanidae , the only other family of boxfishes, are ornamented with a central spine from which radiating lines of tubercles emanate.

Stratigraphic and geographic range in Alabama

The specimens in our sample were collected from the lower Tallahatta Formation at site ADl-1, the contact of the Tallahatta and Lisbon formations at sites ACh-14 and ACov-11, the basal Lisbon Formation at site ACov-11, the basal Gosport Sand at site ACl-4, and the Gosport Sand at site ACh-21. Upper Ypresian to middle Bartonian, zones NP14 to NP17.

Figures

Fig. 66. Fisherichthys aff. F. folmeri Weems, 1999 and Ostraciidae Rafinesque, 1810, elements. A–L. Fisherichthys aff. F. folmeri. A–C. Tooth, SC2012.43.125.1, basal Lisbon Formation. A. Profile view. B. Oral view. C. Aboral view. D–F. Tooth, SC2012.43.125.2, basal Lisbon Formation. D. Profile view. E. Oral view. F. Aboral view. G–I. Tooth, SC2012.43.125.3, basal Lisbon Formation. G. Profile view. H. Oral view. I. Aboral view. J–L. Tooth, MSC 38501, Gosport Sand. J. Profile view. K. Oral view. L. Aboral view. — M–U. Ostraciidae. M–O. Dermal plate, MSC 35771.1, lower Tallahatta Formation. M. External view. N. Internal view. O. Profile view. P–R. Dermal plate, MSC 37121, Tallahatta/Lisbon formation contact zone, courtesy of Bruce Relihan. P. External view. Q. Internal view. R. Profile view. S–U. Dermal plate, MSC 37418, basal Gosport Sand. S. External view. T. Internal view. U. Profile view. Scale bars: A–L=1 mm; M–R =5 mm; S–U= 2 mm.