Figure 7
Topics for Discussion: (a–e) Differentiation between traces of druses and pollen. LM image of Sample Ro-58.5 (‘Zizyphus zizyphoides’) with pollen-like structures randomly distributed. Their shape resemble conifer pollen. (b) Sample Ro-4.4 (‘Acer integrilobum’); the globules of ca. 100 µm diameter, distributed on (left side) and beside (right side) leaf area may be pollen. (c–e) Sample Ro-2.2 (‘Sideroxylon’) with different leaves. The larger ones contain globules of different size (d), the other one small black particles (e), no globules were found in the mineral sediment. Such patterns cannot originate from pollen. (f–j) Uncertainty in the identification of leaf fossils. (f) LM image of sample Ro-13.3, which has been assigned to ‘Nymphaea nymphaeoides’, shows black granules. (g–h) SEM images of a fresh leaf of Nelumbo nucifera (Lotus) show CaOx druses in similar distribution and size as sample Ro-13.3; inset (h) shows a single druse in detail. (i,j) SEM images of mesophyll cells in a fresh leaf of Nymphaea lotus, carrying only small CaOx crystals (< 5 µm) (i) on the surface of sclereid cells (j). Scale bars: (a) = 100 µm; (b) = 500 µm; (c) = 5 mm; (d,e,f,g) = 200 µm; (h,i) = 10 µm; (j) = 100 µm.
