Figure 4. Analyses of a section through an embedded glochidiate trichome with hooks.

(a) Surface view of a glochidic trichome. (b) BSE image of the sectioned block face showing compositional contrast. Higher brightness indicates higher content of the mineral elements Ca and P in the hooks. (c) EDX spectra of the hook tips and the main wall show high calcium phosphate and low carbon concentration in the hook tips. (d–f) Element mapping images show high P concentration and low C concentration in the hook tips. The Ca concentration is high in the hooks and slightly lower in the main wall. (g) The toluidine blue-stained thin section of another glochid indicates organic material in the main wall, whereas the hook tip appears almost unstained and free of carbohydrates.