Fig. 8 in Triassic coleoid beaks and other structures from the Calcareous Alps revisited

Fig. 8. Hypothesized "beak" of the coleoid cephalopod Phragmoteuthis bisinuata (Bronn, 1859) (GBW 2006/011/0009), lower Carnian, Upper Triassic, Cave del Predil, NE Italy. A fracture of the "beak". A1, a dimpled outer surface of the "beak" coated by a shale; A2, "glassy" structureless matrix and whitish fractured compressed bone-like nanostructure; A3, dense wall of bone-like nanostructure; A4, a dimpled outer surface of the wall of the bone-like nanostructure.