Fig. 3 in Middle Ordovician Drepanoistodus (Vertebrata, Conodonta) from Baltica, with description of three new species

Fig. 3. Geniculate Drepanoistodus basiovalis (Sergeeva, 1963) element demonstrating the essential morphological characteristics utilized in the present study. Two characters were measured quantitatively: Angle A between the median line (usually carina) of the cusp and the lower margin of the keel situated on the upper margin of the cusp (A); and the b/c ratio, which is the ratio between the length of the upper margin of the base (b) and the length of the free cusp (c).