Pachygymnura attiai, Adnet & Marivaux & Cappetta & Charruault & Essid & Jiquel & Ammar & Marandat & Marzougui & Merzeraud & Temani & Vianey-Liaud & Tabuce, 2020
|
publication ID |
https://doi.org/ 10.26879/1085 |
|
publication LSID |
lsid:zoobank.org:pub:B6B8E985-F1CF-4C10-BB00-602E5BF36C1C |
|
persistent identifier |
https://treatment.plazi.org/id/03BA87C1-FFD3-FFC4-C1E1-E05DC867B759 |
|
treatment provided by |
Felipe |
|
scientific name |
Pachygymnura attiai |
| status |
|
Pachygymnura attiai (Cook in Murray et al., 2010) nov. comb.
Figure 11 View FIGURE 11 D-H
zoobank.org/ 9E15A4B6-1623-4CD3-83A6-5BCBF7A3ED96
2010 Coupatezia attiai Cook in Murray et al.; Murray et al, p. 669, figs. 1G, 2A.
2011? Jacqhermania attiai (Cook in Murray et al.); Underwood et al., p. 53-62, fig. 7 F-G.
2011? Jacqhermania attiai (Cook in Murray et al.); Adnet et al., p. 35-36, fig. 4O.
2016 “ Jacqhermania” attiai (Cook in Murray et al.); Merzeraud et al., p. 14-15, tab. 1.
Material. One hundred teeth from the KEB- 1 locality, Souar-Fortuna formations, Djebel el Kébar,
Tunisia, including those figured KEB 1-183 to 1-
187 ( Figure 11 View FIGURE 11 D-H).
Description
Cook in Murray et al. (2010) proposed the first description of Coupatezia attiai , the type species of the new monotypic genus. Compared to their scarce material, the KEB-1 material counts several hundreds of teeth. However, the morphologies of teeth are quite similar, thereby testifying the very faint heterodonty in this taxon. No sexual nor dignathic heterodonty is clearly identified in this large KEB-1 sample. Some teeth ( Figure 11 View FIGURE 11 D-F) are more laterally positioned based on the slight increase in mesiodistal width. Conversely, the most anterior teeth (e.g., Figure 11 View FIGURE 11 G-H) are slightly longer than wide, forming sometimes some asymmetrical folds on the labial face (e.g., Figure 11G View FIGURE 11 ). As observed by Murray et al. (2010), the nutritive groove also contains multiple smaller foramina rather than a single large foramen in some teeth .
Remarks
Formerly recognized as Coupatezia attiai Cook in Murray et al., 2010, this new taxon can be differentiated from Coupatezia inasmuch as it possesses a smooth and flat occlusal crown surface, without any ornamentation nor transversal labial crests, a lack of individualised cusp, and two rounded root lobes that are asymmetrical and labially extended. Nevertheless, as previously remarked by Murray et al. (2010), this morphology is quite comparable to that of Coupatezia laevis Noubhani and Cappetta, 1993 , from the Danian of Imin Tanout, Morroco. Differing from C. laevis in possessing a labial face that is completely flat, a lingual face that approaches the length of the labial face in profile view, and in a root more massive with root lobes more convex, Murray et al. (2010) already suggested that Pachygymnura attiai (formally C. attiai ) and C. laevis should be removed from the genus Coupatezia . Underwood et al. (2011) and Adnet et al. (2011) later reported similar teeth in the Middle-Late Eocene of Egypt that were considered to have more affinities to the fossil gymnurid Jacquhermania Cappetta, 1982 . Affinities to gymnurids are supported by: a root morphology that is extended mesiodistally in both fossil (e.g., Ouledia , Jacquhermania ) and living gymnurids (see also Herman et al., 1998; Guinot et al., 2018), the crown faces with smooth enameloid only separated by a long cutting transverse crest, and the concave labial visor, which is particularly rounded in profile. However, the type species Jacquhermania duponti (Winkler 1874) recovered from the Early-Middle Eocene of the North Atlantic (Kent, 1999; Cappetta and Case, 2016) has larger teeth with more mesiodistally enlarged roots, and a strongly cuspidate crown, thereby justifying the description of a new genus. The systematic affinity of Pachygymnura nov. gen. remains unclear, and as such it is provisionally placed in Gymnuridae . Abundant in Djebel el Kébar, this species was also recovered from Priabonian deposits of Egypt (BQ, QS, KM), including coastal deposits with fresh water influence in BQ2 (Murray et al., 2010). This genus is likely to be known since the Middle Eocene of West Africa (Sambou et al., 2020) and Pachygymnura attiai nov. gen. was also observed in material from EG (pers. observ. SA, HC).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.