GBIF Taxonomic Backbone & Wikipedia Registry Profile
Remarks The A. minutissima anterior teeth in our sample have a single pair of lateral cusplets in all tooth positions, whereas two species formerly placed within Abdounia (see below), A. claibornensis and A. recticona, have three-to-eight pairs. The anterior teeth of A. minutissima were distinguished from those of A. beaugei by having lateral cusplets that are taller, more slender, and more conspicuously differentiated from the main cusp. The teeth of A. minutissima differ from those of A. enniskilleni by their smaller size and more gracile appearance, by having a smooth lingual crown face, and by having narrower lateral cusplets. Cappetta & Case (2016) referred 120 teeth from the contact of the Tallahatta and Lisbon Formation at site ACov- 11 to Abdounia sp. and questioned the assignment of teeth to A. minutissima by Clayton et al. (2013). Cappetta & Case (2016) stated that the 120 teeth were similar to those of A. minutissima, but noted that they lack short folds at the base of the labial crown face and have a thicker root. However, the type specimens of A. minutissima originally illustrated by Winkler (1874 a) lack any labial folds, and the presence of such ornamentation was not mentioned by either Winkler (1874 a) or later by Daimeries (1891). The presence of faint labial ornamentation on the teeth of A. minutissima was first reported by Leriche (1905), but he noted that these vertical striations are extremely faint, almost invisible to the naked eye, and were extremely susceptible to abrasion. This lack of ornamentation on certain teeth is substantiated by its absence on several figured A. minutissima specimens by other authors, at least one of which was derived from the type locality in Belgium (see Van den Eeckhaut & De Schutter 2009: pl. 20, fig. 6). Furthermore, an examination of the A. minutissima teeth in our sample suggests that the thickness of the root is variable and can be attributed to heterodonty. Additionally, the presence or absence of labial ornamentation, as well as root thickness and cusplet morphology, is variable in large samples of A. enniskilleni teeth from both Alabama and South Carolina that we examined. The taxonomic utility of crown ornamentation may not be significant (Purdy et al. 2001), as it is also variable within the various species of Premontreia that have been identified (Cappetta 1992; Noubhani & Cappetta 1997). Stratigraphic and geographic range in Alabama The specimens in our sample were collected from the lower Tallahatta Formation at site ADl- 1, the Tallahatta Formation at AMo- 8, the contact of the Tallahatta and Lisbon formations and the basal Lisbon Formation at site ACov- 11, the contact of the Lisbon Formation and Gosport Sand at site AMo- 4, the basal Gosport Sand at site ACl- 4, and the Gosport Sand at site ACl- 15. Upper Ypresian to middle Bartonian, zones NP 14 to NP 17.
