Fig. 10

Results of nanoindentation. Hardness (GPa) and Young’s modulus (GPa) for all cusps (central, lateral, marginal, with N = quantity of measured cusps) for each species (N = quantity of measured specimens) correlated with the preferred feeding substrate (circle = mud, hexagon = sand, square = plants, triangle = rock). Connecting letters from Tukey–Kramer test can be found in Table 1