Scales and Tooth Whorls of Ancient Fishes Challenge Distinction between External and Oral ‘Teeth’
Figure 2
The scanned scale of Andreolepis hedei Gross, 1968.
A. Scanned part of the scale (PMU 24786) rendered in VG Studio 2.1, crown view, red line marking the position of the slice in B. B. Longitudinal virtual thin section from the synchrotron scanning data, the red rectangle marking the region in C. C. Close-up of B, showing the segmentation of odontodes and the tissue composition of the crown (picture exported from VG Studio 2.1). The numbers in circles correspond to the odontodes in following Figures 3 and 4. D. A real thin section (PMU 24784) from an Andreolepis body scale made in the anteroposterior plane for comparison (DIC, optical microscopy); the scale is slender and comes from the posterior region of the body [28]. Abbreviations: e, enamel; d, dentine; hc, horizontal vascular canal, O1-O5, odontodes 1–5, Shb, Sharpey’s fibers.