Coupatezia cristata, Adnet & Marivaux & Cappetta & Charruault & Essid & Jiquel & Ammar & Marandat & Marzougui & Merzeraud & Temani & Vianey-Liaud & Tabuce, 2020

Adnet, Sylvain, Marivaux, Laurent, Cappetta, Henri, Charruault, Anne-Lise, Essid, El Mabrouk, Jiquel, Suzanne, Ammar, Hayet Khayati, Marandat, Bernard, Marzougui, Wissem, Merzeraud, Gilles, Temani, Rim, Vianey-Liaud, Monique & Tabuce, Rodolphe, 2020, Diversity and renewal of tropical elasmobranchs around the Middle Eocene Climatic Optimum (MECO) in North Africa: New data from the lagoonal deposits of Djebel el Kébar, Central Tunisia, Palaeontologia Electronica (a 38) 23 (2), pp. 1-62 : 38-40

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/3BC6CE15-E4B3-412D-BFDC-5C64F6198255

taxon LSID

lsid:zoobank.org:act:3BC6CE15-E4B3-412D-BFDC-5C64F6198255

treatment provided by

Felipe

scientific name

Coupatezia cristata
status

sp. nov.

Coupatezia cristata nov. sp.

Figure 13 View FIGURE 13 A-E zoobank.org/ 3BC6CE15-E4B3-412D-BFDC-5C64F6198255

2007 Coupatezia sp. ; Strougo et al., p. 88-94, pl. 3,

figs. 3-4.

2016 Coupatezia sp ; Merzeraud et al., p. 14-15, tab.

1.

Etymology. Cristata , considering the peculiar labial extremity of crown that bear many enameloid crests.

Type locality and Stratum. KEB 1-205 ( Figure 13A View FIGURE 13 ) from the KEB-1 locality, Souar-Fortuna formations in Djebel el Kébar, Tunisia .

Other material. Additional material, including figured KEB 1-206 to 1-209 ( Figure 13 View FIGURE 13 B-E), principally consists of about 200 teeth from the KEB- 1 locality, Souar-Fortuna formations, Djebel el Kébar, Tunisia.

Diagnosis. Species of Coupatezia characterized by large teeth (up to 5 mm mesiodistally wide) and only known by “female” tooth morphology, suggesting the lack of any gynandric heterodonty in this species. This species is also characterized by a combinations of many characters separately observed in “female” teeth of other species, as: teeth always broader than long (e.g., like C. bojoi , C. larivei , C. reniformis , C. wouterzi ), crown having a deeply concave occlusal part of the labial face (e.g., like C. fallax , C. ambroggii ), and sometimes of the lingual face; both surfaces of crown are finely ornamented with alveolar web of enameloid (e.g., like C. larivei ); a labial visor strongly irregular in occlusal or labial view (e.g., like C. fallax ).

Description

Almost all species of Coupatezia exhibit usually gynandric heterodonty, with male teeth (at least during the breeding period) having a cuspidate, triangular crown and with female teeth with uncuspidate, elliptic crown, as reported here. However, and as also observed in the Danian species C. melitiana Noubhani and Cappetta, 1997 , there is no evidence of sexual dimorphism in the material of C. cristata nov. sp. from KEB which consists of 200 teeth, nor in the other contemporenous sample from Egypt where the new species occurs abundantly (EG). The crown seems never really cuspidate, assuming that some males were present in all or a part of all theses samples/localities. Of course, we cannot unambiguously exclude that lack of cuspidate teeth was due to male departure outside the lagoon during the breeding period. The teeth have a crown broader than long in occlusal view, and as broader as the root breadth. The outline of the crown is elliptical ( Figure 13C View FIGURE 13 1, D1 View FIGURE 1 ) or kidney-shaped ( Figure 13A View FIGURE 13 1, E1 View FIGURE 1 ), with a labial concavity, more or less developed according to the file considered. The labial face of the crown is deeply concave, highlighted by a strong concavity in profile, as observable in the holotype ( Figure 13A View FIGURE 13 2 View FIGURE 2 ). Lingually, this concavity is limited by a rather transverse keel, which reaches labially the irregular crests ( Figure 13A View FIGURE 13 1, E1 View FIGURE 1 ). In the front of these labial crests, there is a narrow area all along the limit of the labial visor. The surface of this narrow area is strongly rugose with numerous transversal and vertical ridges that mark the upper part of the labial visor ( Figure 13A View FIGURE 13 1 View FIGURE 1 , C 3 View FIGURE 3 ). The surface of the labial face is covered by a fine but well-marked alveolar ornamentation of enameloid ( Figure 13C View FIGURE 13 2, D2 View FIGURE 2 ); its lingual border, near the transverse keel, is sometimes highlighted by a series of regular short wrinkles ( Figure 13A View FIGURE 13 1 View FIGURE 1 ). The lingual face is slightly concave and the enameloid is quite smooth ( Figure 13E View FIGURE 13 2 View FIGURE 2 ) to well-ornamented ( Figure 13A View FIGURE 13 1 View FIGURE 1 ). In lingual view, the margin of the crown is straight. The chopped labial visor clearly overhangs the root. The root is as high as the crown ( Figure 13A View FIGURE 13 2 View FIGURE 2 ). Its labial profile is vertical when its lingual profile is oblique and slightly concave. The basal face is flat and the lobes are separated by a wide and deep furrow where foramina irregularly distributed open ( Figure 13B View FIGURE 13 2 View FIGURE 2 ). The most lateral teeth are transversely elongated. The magnitude of enameloid ornamentation seems scalable on the material, particularly on the lingual face of the crown, which is smooth ( Figure 13E View FIGURE 13 2 View FIGURE 2 ) to widely ornamented ( Figure 13A View FIGURE 13 1 View FIGURE 1 ). Although it is unverified, this variability seems uncorrelated with tooth position or size, and thus, it could be related to a sexual heterodonty.

Remarks

Contrary to the Maastrichtian-Ypresian time window during which more than a dozen of species of Coupatezia occurred (e.g., Cappetta, 1983; Noubhani and Cappetta, 1997; Case and Cappetta, 1997), all of the Middle-Late Eocene reports of the genus have been attributed to the Belgian type species Coupatezia woutersi Cappetta, 1982 , to the deepsea Coupatezia miretrainensis Adnet, 2006 , or more frequently to unnamed species. Cappetta and Case (2016) recently suggested that most of those attributed to C. woutersi and recovered in coastal deposits of Tropical realm during the Middle-Late Eocene (see Cappetta, 2012) document probably to other species. For instance, Case et al. (1996) have reported the occurrence of C. woutersi in the Middle Eocene of Uzbekistan. The figured teeth seem closer to the Lutetian Coupatezia sp. from Lisbon Fm., Alabama, USA (Cappetta and Case, 2016, Ebersole et al., 2019), or those from the Lutetian of Aznag, Morocco (Tabuce et al., 2005) than to typical C. woutersi , mainly because the occlusal ornamentation of the crown is weak. Compared to typical teeth of C. woutersi from the Lutetian of Belgium (see Cappetta, 1982) and all the pre-Lutetian species, the teeth of the new species show clear differences as: an irregular and chopped labial visor coupled with a finer ornamented enameloid of the labial and lingual faces of the crown, and possibly a peculiar absence of sexual heterodonty (unverified). This new species is also distinct from C. miretrainensis Adnet, 2006 , recovered in deep sea deposits of the Middle Eocene (Adnet, 2006, 2008a; Carslen and Cuny, 2014) in having no granular enameloid ornamentation.

Murray et al. (2010) also reported the occurrence of C. woutersi in the Priabonian freshwater deposits of the Fayum, Egypt (BQ-2). These authors, however, remarked that the seven specimens from BQ-2 do not present sexual heterodonty, and would then be identified as lateral positioned teeth of female Coupatezia . Considering the peculiar irregular labial visor (Murray et al., 2010, figure 2B), the material from BQ-2 is quite similar to those of C. cristata nov. sp. However, the labial face of BQ- 2 specimens (as those from KM in Adnet et al., 2011, and from QS in Underwood et al., 2011, figure 7D-E) is without any ornamentation. It makes sense to remain prudent about the attribution of the Priabonian specimens from Egypt to Coupatezia cristata nov. sp., even if we can nevertheless support affinities with the Bartonian KEB- 1 species. In addition, the Middle Eocene material attributed to Coupatezia sp. from EG (Strougo et al., 2007, plate 3, figures 3-4) could be now attributed to C. cristata nov. sp. without any doubt (pers. observ. SA, HC).

Specimens repositories. Holotype and Paratypes are deposited in the paleontological collections of the museum of the “ Office National des Mines ” of Tunis , 24 rue 8601, 2035 La Charguia, 1080 Tunis, Tunisia

Temporal range. Uppermost Lutetian-lowermost Bartonian ( Egypt) to Middle Bartonian ( Tunisia).

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