FIGURE 4 in Evolutionary convergence in conodonts revealed by Synchrotron-based Tomographic Microscopy

FIGURE 4. Microtomographic longitudinal sections focused on the posterior platform of Epigondolella quadrata and E. rigoi, aimed to show the ontogenesis of the posterior node growing behind the cusp. For each section a 3D model of the correspondent conodont is provided. Beside the sections, the outlines of selected growth lines are reported, in order to evidence some visible growth stages and show the different ontogenetic processes of E. quadrata and E. rigoi. Arrows and letters (a, b, c) mark the growth lines considered to draw the stages. 1, E. quadrata A; 2, juvenile specimen of E. quadrata from sample NA60 (from Mazza and Martínez-Pérez, 2015; repository number Micro-Unimi no. 2001); 3, E. quadrata B; 4, E. quadrata C; 5, E. rigoi A; 6, juvenile specimen of E. rigoi from sample NA68 (from Mazza and Martínez-Pérez, 2015; repository number Micro-Unimi no. 2003), showing that the posterior node is already occurring; 7, E. rigoi B. Scale bars equal 200 µm. Legend: cu, cusp; pn, posterior node.