Fisherichthys, Weems, 1999

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 : 178-180

Fisherichthys aff. F. folmeri Weems, 1999

Fig. 66 A–L

Fisherichthys folmeri Weems, 1999: 63 , pls 4.7d, 4.8a–b.

Albula eppsi – Case 1994b: 142 , pl. 1, figs 372–375.

cf. Fisherichthys sp. – Clayton et al. 2013: fig. 6k–l.

Material examined

UNITED STATES OF AMERICA – Alabama • 6 isolated teeth; Claiborne Group ; MSC 38501, SC 2012.47.125 (2 specimens), SC 2012.47.237, SC 2012.47.238, SC 2012.47.239 .

Description

Small teeth measuring up to 1.5 mm diameter, 1.0 mm crown height. Tooth crown conical in profile, with flat apex. Crown covered by smooth enameloid; apical surface with shallow depression surrounded by small tubercles. Occlusal surface of worn teeth composed of dentine, with a thin outer enameloid layer. Crown base thick, with basal cingulum. Circular basal pulp cavity centrally located.

Remarks

Six specimens in our sample are tentatively assigned to Fisherichthys folmeri because they exhibit the features of the type and only known species. The conical profile, apical tubercles, and basal cingulum serve to distinguish teeth of Fisherichthys in our sample from the somewhat similar teeth of Albula , Paralbula , Pycnodus , and Egertonia .

The occurrence of Fisherichthys in Claiborne Group strata, particularly in the Gosport Sand, represents the stratigraphically youngest records for the genus, which was previously not known to occur beyond Zone NP11 of the Ypresian Stage ( Case 1994b; Weems 1999; Cicimurri & Knight 2009). Our tentative species identification is due to our small sample size and much younger stratigraphic occurrence.

Stratigraphic and geographic range in Alabama

The specimens in our sample were collected from the basal Lisbon Formation at site ACov-11 and the basal Gosport Sand at site ACl-4. Lower Lutetian to middle Bartonian, zones NP15 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.