Fig. 4.

(a) μCT image of the mature end of the radula. (b) Longitudinal section of two consecutive mature major lateral teeth. (c) SEM micrograph of an extracted mature major lateral tooth. (d) Optical micrograph of an extracted row of inter-locked mature major lateral teeth. (e) SEM micrograph of a mature R tooth enclosed by 4 unicuspid mLT. The arrows point at the two external underdeveloped mLT (abbreviated same as in Fig. 2). (f) μCT images of a longitudinal cross-section of the mature end of radula with the central tooth marked in red. (g) SEM micrograph of mature marginal teeth. Inset: a magnification depicting smaller hair-like structures (denoted by the arrow) covering the surface of marginal teeth. The scale bars in (a–g) are all 500 μm. The scale bar in the inset of (g) is 50 μm. The scale bar in the μCT image (a) is used as a guide to the eye.