Garabatis sp.

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 : 41

Garabatis sp.

Figure 13 L-M

2016 Garabatis sp ; Merzeraud et al., p. 14-15, tab. 1. Material. Five small median teeth, partially abraded, from the KEB-1 locality, Souar-Fortuna sormations, Djebel el Kébar, Tunisia, including the two figured specimens KEB 1-216, -217 ( Figure 13 L-M)

Description

The small median teeth (no more than 5 mm long) show a myliobatid design with elongated crown of peculiar sigmoid outline in occlusal view, higher than the root of variable thickness in lingual view. The occlusal face of crown is slightly convex labiolingually. When not or slighty abraded by functional wear, the crown is entirely covered by a pitted enameloid, with depressions of circular or elliptic outline small but deep, especially on the margins of the crown ( Figure 13L 3 ). Contrary to what Hovestadt and Hovestadt-Euler (2013) advocated, pitted enameloid in Garabatis is not caused by marine organisms before or post depositional diagenesis. Comparatively to the unique species Garabatis atlasi Cappetta, 1993 , the occlusal face of crowns seems more convex with sometimes the presence of a median crest abraded by functional wear, as observable in such crushing teeth ( Figure 13L ).

Remarks

Contrary to the large contemporenaous myliobatid Leidybatis with tooth crown showing quite similar enamel ornamentation, there is no elongated medial teeth with transversaly convex prominence in our sample. Moreover, the lingual face of crown is always smooth in Garabatis , at the contrary to that is observable in Leidybatis . This monospecific genus is known since the Thanetian in North African areas with the Moroccan species Garabatis atlasi (Cappetta 1993) , and was already recorded in the Middle Eocene of Morocco (Tabuce et al., 2005), Egypt (EG: Strougo et al., 2007) until the Priabonian (Lower QS) of the Fayum area (Underwood et al., 2011), and Southwestern Morocco (Adnet et al., 2010).

Figures

FIGURE 3. A-N: Carcharhinus kasserinensis nov. sp. A. Parasymphyseal upper tooth KEB 1-086, A1. labial view, A2. Lingual view; B. HOLOTYPE Anterior upper tooth KEB 1-087, B1. Labial view, B2. Lingual view, B3. Magnificence of mesial cutting edge; C. Antero-lateral upper tooth KEB 1-088, C1. Labial view, C2. Lingual view; D. Antero-lateral upper tooth KEB 1-089, D1. Labial view, D2. Lingual view; E. Antero-lateral upper tooth KEB 1-226, E1 Lingual view, E2. Labial view; F. Antero-lateral upper tooth KEB 1-227; G. Antero-lateral upper tooth KEB 1-090, G1. Labial view, G2. Lingual view; H. Lateral upper tooth KEB 1-091, labial view; I Posterior upper tooth KEB 1-092, lingual view; J. Symphyseal abnormal lower tooth KEB 1-093, J1. Labial view, J2. Lingual view; K. Anterior lower tooth KEB 1-094, labial view; L. Anterior lower tooth KEB 1-095, L1. Labial view, L2. Lingual view; M. Antero-lateral lower tooth KEB 1- 096, M1. Labial view, M2. Lingual view; N. Antero-lateral lower tooth KEB 1-097, N1. Lingual view, N2. Labial view, N3. Profile.

FIGURE 13. A-E. Coupatezia cristata nov. sp. A. antero-lateral tooth KEB 1-205, HOLOTYPE, A1.occlusal view, A2. Profile, A3. Labial view; B. Anterior tooth KEB 1-206, B1. Lingual view, B2. Basal view, C. lateral tooth KEB 1-207, C1. Occlusal view, C2. Magnificence of C1, C3. Lingual view; D. lateral tooth KEB 1-208, D1. Occlusal view, D2. Magnificence of D1, D3. Lingual view; E. lateral tooth KEB 1-209, E1. Occlusal view, E2., lingual view, E3. Basal view. F-G. Rhinoptera sp. F. medium tooth KEB 1-210, lingual view, G. medium tooth KEB 1-211, labial view; H-J. Myliobatis sp., H. lateral tooth KEB 1-212, lingual view, I. medio-lateral tooth KEB 1-213, lingual view, J lateral tooth KEB 1-214, lingual view; K. Aetobatus sp. KEB 1-215, ligual view, L-M. Garabatis sp., L. KEB 1-216, occlusal view, M. KEB 1-217, L1. occlusal view, L2. Magnificence of central part, L3. Magnificence of marginal part of crown.