Fig. 3

Fragmentary Tafilalt topotypes of Chebbites from the Metabactrites Shale. a–cCh. reisdorfi Morphotype 2 (typical morphotype with marked ribs), B6C.51-6, Bou Tchrafine Pass (for locality description see Becker et al. 2018d), lateral and dorsal view, showing the dorsal sinus of growth lines at 20 mm wh, × 2. d–fCh. reisdorfi Morphotype 1 (with dense ribbing), B6C.51-7, Bou Tchrafine West, ventral, lateral, dorsal, and septal views showing the narrow E-lobe and ventral ribbing, the deep flank lobe, a rather weak imprint zone with incipient dorsal lobe, and the typical, compressed cross-section, × 2. g–i Juvenile Ch. reisdorfi Morphptype 3 (weakly ribbed), B6C.51-8, Bou Tchrafine Pass, lateral, ventral, and dorsal views, showing a pouched E-lobe, deep L-lobe, and well-developed I-lobe, ×3. j–l Juvenile Ch. reisdorfi Morphotype 2, B6C.51-9, Bou Tchrafine Pass, lateral, slightly oblique dorsal, and ventral views, showing coarse ribbing, a narrow imprint zone, shallow I-lobe, and ventral impressions, ×4. m–oCh. maghribensis, B6C.51-10, Ouidane Chebbi (for section description see Belka et al. 1999; Klug 2001, and Klug et al. 2008), somewhat transitional towards Ch. reisdorfi, lateral, ventral, and dorsal views, showing weak flank ribbing, typical ventral impressions, a wide E-lobe, and well-developed I-lobes, ×2. p–rCh. cf. maghribensis, B6C.51-11, Ouidane Chebbi, lateral, ventral, and dorsal views, showing a completely smooth flank, very weak ventral ornament, a shallow but wide E-lobe, and very incipient imprint zone and I-lobe, ×2.5