Coupatezia, Cappetta, 1982

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 : 117-118

Coupatezia sp.

Fig. 42 A–L

Coupatezia woutersi Cappetta, 1982: 18 , pls 2–3.

Coupatezia woutersi – Clayton et al. 2013 : fig. 5a–b.

Coupatezia sp. – Cappetta & Case 2016: 65, pl. 13, figs 1–6.

Material examined

UNITED STATES OF AMERICA – Alabama • 18 isolated teeth; Claiborne Group ; MSC 35786, MSC 37309.1 – 3 , MSC 37339, MSC 37671, MSC 38480.1 – 3 , SC 2012.47.6, SC 2012.47.7 (6 specimens), WSU 22 , WSU CC 502.1 .

Description

All teeth in our sample low-crowned. Teeth with elliptical outline in oral view. Labial face deeply convex, framed by cingulum-like margin. Base of labial face bears transverse crest that may be simple or appear reticulated; does not reach the sides of the crown. Lingual face of crown convex or sinuous in profile, unornamented. Crown overhangs the root on all sides. Roots bilobate. In labial or lingual views, mesial and distal extent of roots extend slightly beyond the crown foot. In profile the root extends well beyond the lingual crown margin, but labially crown conspicuously overhangs root. Deep nutritive groove bisects the root equally, and basal face of lobes convex with triangular outline.

Remarks

Coupatezia appears to exhibit gynandric heterodonty, with male teeth having a more cuspidate, triangular crown ( Cappetta 1982; Noubhani & Cappetta 1997). Unfortunately, the 18 specimens available to us all exhibit the purported female morphology (described above). Clayton et al. (2013) assigned their sample of Coupatezia teeth from site ACov-11 to C. woutersi , a species described from the Lutetian of Belgium ( Cappetta 1982), but Cappetta & Case (2016) did not speciate the specimens in their sample from the same site. The latter authors cited morphological differences between the Alabama teeth and C. woutersi specimens from the type locality in Belgium, including a less ornamented labial face, more regular labial crown margin, and root lobes that extend further distally on C. woutersi . The Alabama specimens differ significantly from female teeth of Lutetian C. miretrainensis Adnet, 2006 in having a more rounded occlusal outline, more concave labial face, and nodular labial crown ornament. Female teeth of the Ypresian species C. boujoi Noubhani & Cappetta, 1997 appear to have a more concave labial crown margin, and the basiolabial transverse crest is less conspicuous, sometimes merging with the crown margin. With regard to the Alabama specimens, we found that the outline of the labial crown margin varies from concave, straight, to convex, and the crown margin itself can be sharp, nodular, or weakly developed. Also, the basiolabial transverse crest of the labial face may be simple or have a reticulated appearance, and the root lobes vary in distal length. This variation, coupled with the fact that we cannot compare a male tooth with any of the described Eocene species, makes it difficult to ascertain if the Alabama taxon is distinct or conspecific with any of them. Thus, we chose here to refrain from a specific identification.

Stratigraphic and geographic range in Alabama

The specimens in our sample were collected from the lower Tallahatta Formation at site ADl-1 and the basal Lisbon Formation at site ACov-11. Upper Ypresian to lower Lutetian, zones NP14 and NP15.

Figures

Fig. 42. Coupatezia sp. and Hypolophodon sylvestris (White, 1931), teeth. — A–L. Coupatezia sp. A–D. MSC 37339, basal Lisbon Formation. A. Basal view. B. Basiolabial view. C. Oral view. D. Profile view. E–H. MSC 35786.1, lower Tallahatta Formation. E. Basal view. F. Basiolabial view. G. Oral view. H. Profile view. I–L. MSC 38480.2, basal Lisbon Formation. I. Basal view. J. Basiolabial view. K. Oral view. L. Profile view. — M–X. Hypolophodon sylvestris. M–O. MSC 35788.1, lower Tallahatta Formation.M. Oralview.N. Basalview.O. Lingual view.P–R.MSC 35788.2, lowerTallahatta Formation. P. Oral view. Q. Basal view. R. Lingual view. S–U. MSC 35788.3, lower Tallahatta Formation. S. Oral view. T. Basal view. U. Profile view. V–X. MSC 35788.4, lower Tallahatta Formation. V. Oral view. W. Basal view. X. Lingual view. Scale bars: A–L= 1 mm; M–X= 2 mm.