Arambourg, 1935: 430
Leriche, 1936: 391
Dartevelle & Casier 1943: 154
Arambourg 1952: 123
Cappetta 1980a: 35
Cappetta & Case 2016: 56
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
Ebersole, Jun A.
Cicimurri, David J.
Stringer, Gary L.
European Journal of Taxonomy
2019
2019-12-06
585
1
274
(Arambourg, 1935)
Arambourg
1935
[566,1021,1899,1926]
Elasmobranchii
Carcharhinidae
Abdounia
GBIF
Animalia
Carcharhiniformes
81
82
Chordata
species
beaugei
Fig. 30
Eugaleus beaugei Arambourg, 1935: 430, pl. 14, figs 28–35. Galeus doncieuxi Leriche, 1936: 391, pl. 27, fig. 9. Galeorhinus beaugei– Dartevelle & Casier 1943: 154, pl. 12, figs 40–46. Scyliorhinus beaugei– Arambourg 1952: 123, pl. 23, figs 20–47. Abdounia beaugei– Cappetta 1980a: 35, fig. 4. Abdounia biauriculata– Cappetta & Case 2016: 56, pl. 7, fig. 5.
Material examined UNITED STATES OF AMERICA– Alabama• 50 isolated teeth; Claiborne Group; MSC35754.1– 13, MSC37133, MSC37318.2, MSC37318.4, MSC37570.3– 5, MSC37571.1– 21, MSC37572, MSC37695.2, SC2012.47.167, SC2012.47.177 ( 4 specimens), WSU CC 510( 2 specimens).
Description Anterior teeth with tall erect main cusp; cusp of lateral and lateroposterior teeth becoming shorter, more distally inclined. Anterior teeth with single pair of short, triangular cusplets; cusplets divergent and largely united to main cusp. Lateral teeth with two pairs of lateral cusplets; second pair smaller, vestigial on more distally located teeth. Lingual face of main cusp of anterior teeth strongly convex; less convex on lateral teeth. Labial cusp face flat; all enameloid smooth. Cutting edges of main cusp and lateral cusplets smooth, continuous. Root bilobate with short, diverging lobes. Lingual attachment surface flat; wide and deep nutritive groove.
Remarks Three species of Abdouniahave been identified within our sample of Claiborne Group teeth, including A. beaugei( Arambourg, 1935), A. enniskilleni( White, 1956), and A. minutissima(Winkler, 1874). Two additional species previously assigned to Abdouniaare placed within a new genus and are described in detail below. The A. beaugeianterior teeth in our sample have a single pair of lateral cusplets, easily separating them from the latter two species, which have three-to-eight pairs. Anterior teeth of A. minutissimahave taller triangular cusplets that are less united to the main cusp. Teeth of A. enniskilleniare much larger in overall size and generally have fine longitudinal ridges on the lingual cusp face. The lateral teeth of A. beaugeihave two pairs of lateral cusplets, whereas A. enniskilleniand A. minutissimahave a single pair. Fig. 30. Abdounia beaugei( Arambourg, 1935), teeth. A–C. MSC35754.1, anterolateral tooth, lower Tallahatta Formation. A. Labial view. B. Mesial view. C. Lingual view. D–F. MSC37571.1, lateral tooth, Gosport Sand. D. Labial view. E. Mesial view. F. Lingual view. G–I. MSC37571.2, anterior tooth, Gosport Sand. G. Labial view. H. Mesial view. I. Lingual view. J–L. MSC35754.9, lateral tooth, lower Tallahatta Formation. J. Labial view. K. Mesial view. L. Lingual view. Scale bars for A–L=2 mm. Cappetta & Case (2016)described and figured a single tooth from site ACov-11 that they assigned to Abdounia biauriculata( Casier, 1946). Teeth of to this species are very similar in size to those of A. beaugei, and anterior teeth of both species have a single pair of cusplets and the lateral teeth two pairs (see Arambourg 1935: text fig. 23, pl., 19, figs 28–35; Casier 1946: pl. 1, 6; Arambourg 1952: pl. 23, figs 20–47; Casier 1966: pl. 3, figs 23–25). Although Casier (1966: fig. 65) stated that the two taxa were “analogous”, he reported that his Ypresian A. biauriculatafrom Belgiumdiffered from Arambourg’s (1952) A. beaugeifrom the Ypresian London Clay and Thanetian to Ypresian strata of Moroccoin that the teeth have a less robust root, and the lateral cusplets that are taller, straighter, more pointed, and more separated from the main cusp. When compared to the teeth in our sample, the Abdounia biauriculataspecimen figured by Cappetta & Case (2016: pl. 7, fig. 5) appears anomalous as it has two pairs of tall, pointed cusplets that are separated from the main cusp. Although this single tooth could be identified as A. biauriculata, the absence of any other specimens in our sample leads us to believe that it may represent an aberrant A. minutissima.A few teeth from our sample of Gosport Sand Abdouniateeth have similar tall and pointed cusplets. However, in our opinion these teeth still fall within the morphological range of A. beaugei. Furthermore, as eluded to by Casier (1966: fig. 65), A. beaugeiand A. biauriculatamay be conspecific, with any observed differences being the product of heterodonty and/or intraspecific or geographic variation. Support for this stems from the difficulty, at times, in distinguishing these two morphologies, and the fact that the morphologies appear to be coeval within the same deposits in Belgium(see Noubhani & Cappetta 1997). Based on samples from both Alabama (see below) and Georgia(also Parmley & Cicimurri 2003), the variation we observed in A. enniskillenileads us to believe that Cappetta & Case’s (2016) A. biauriculatais synonymous with A. beaugei. Numerous teeth in our sample are assigned to Abdouniasp. (see Appendix 1) because of their incomplete preservation, making their specific assignments unclear. Stratigraphic and geographic range in Alabama Abdounia beaugeispecimens have been recovered from the lower Tallahatta Formation at site ADl-1, the contact of the Tallahatta and Lisbonformations and the “lower” LisbonFormation at site ACov- 11, the lower Gosport Sand at site ACl-4, and the Gosport Sand at ACl-15. Upper Ypresian to middle Bartonian, zones NP14 to NP17.
2564277929
MSC, SC, WSU
United States of America
Claiborne Group
82
83
MSC 35754.1, 13, MSC 37318.2, MSC 37318.4, MSC 37570.3, 5, MSC 37571.1, 21, MSC 37695.2, CC 510
6
Alabama