FIGURE LEGENDS
Figure 1. Taphonomic (burial) experiments: Experimental and control tubes with sediments and buried Artemia salina . A, B, C – chamosite: A, control without A. salina ; B, sediment withA. salina after 12 months. The black layer contains numerous carcasses, the orange top layer is comprised of carcasses covered by some iron species. C, enlarged area (framed in B) showing spots around nauplii. D, E, F – clinochlore: the same as the previous triplet; multiple light spots around the carcasses are well visible. G, H, I – kaolinite: complex light spots around the carcasses are visible. J, K, L – artificial SiO2; orange coloration marks the layer in which the carcasses accumulated. M – montmorillonite after 5 months. The red layer is well visible; orange and brownish spots (below the red layer) and the orange layer at the bottom are carcasses.
Figure 2. Nauplii of A. salina from different sediments (SEM images, except B). A – well-preserved specimen with limbs and gut (preservational group 1) from the montmorillonite. B, B’ – specimens from the montmorillonite that remained wrapped in clay envelopes after rinsing. C – nauplius from the ASW control with poorly preserved, shapeless body (preservational group 3). D – nauplius from artificial silica, preservational group 2 (overall body shape and limbs preserved, no internal anatomy). E – group 1 specimen from the kaolinite. F – perfectly preserved filter apparatus on antenna 2 of a specimen from the montmorillonite. G – the bases of antenna 2 chaetae with tightly adhered small mineral particles (magnified framed area from E, rotated 90o clockwise). Scale bars 200 μm (A – E), 3 μm (F, G).
Figure 3. Biochemical composition of the carcasses: FT-IR spectra for specimens from the sediments and controls. A – an example of a well preserved specimen (group 1; buried in montmorillonite for 5 years; scale bar 100 μm). B – an example of a poorly preserved specimen (group 4; buried for 1 year in kaolinite; scale bar 100 μm). C – FT-IR of the live control (freshly killed nauplii) and the ASW control. D – wavelength interval containing chitin characteristic bands (gray shadow) in carcasses from all sediments. E - wavelength interval containing proteins characteristic bands (gray shadow) in carcasses from all sediments. F – montmorillonite hosted carcasses (5 years) and corresponding sediment particles; wavelength interval characteristic for the montmorillonite shown in pink shadow; G – the same for the clinochlore. In F and G, red lines are carcasses spectra, blue lines are sediment spectra. H – one-day control in kaolinite and the corresponding kaolinite particles.
Figure 4. Biochemical composition of the carcasses: FT-IR spectra for the best and worst preserved specimens from the kaolinite. Red line – preservational groups 1 and 2 (best preserved specimens), blue line – groups 4 and 5 (worst preserved specimens).
Figure 5. Example of a body surface fragment with points suitable for SEM/EDX analysis of the body (white asterisks) and sediment particles (black asterisks). The carcass is from the chamosite. Bacterial cocci are also visible. Scale bar 4 μm.
Figure 6. Elemental content of the body tissues and adhered sediment particles. Data from SEM/EDX analysis (Table 5). A – Absolute elemental content (average weight percentage) of the body tissues. Aluminium and silicon are increased in the carcasses from the montmorillonite, kaolinite and silica (the three sediments that ensure good preservation). The degree of preservation (Table 3) is shown on the lower diagram. Sediments with better preservation are depicted in capital letters on the horizontal axis. B – Relative elemental content: Body tissues relative to adhered sediment particles, normalised by silicon: ([Element in body]/[Silicon in body])/([Element in particles]/[Silicon in particles]). This ratio shows the extent to which the element enters the carcasses after being dissolved from the sediment.
Figure 7. Results of Simultaneous Thermal Analysis (STA) for montmorillonite (A) and chamosite (B). Green lines – experimental sediments, red lines – control sediments without Artemia salina . New peak at 354°C of ferrihydrite (Földvári, 2011) and shift in endoeffect to 660.7°C shown in A indicate structural disintegration of the montmorillonite. Shift of the first endoeffect from 96.7 to 105°C shown in B indicates accumulation of amorphous phase in the chamosite; shift of the second endoeffect from 513 to 530°C marks leaching of iron from the brucite layer; higher exoeffect 829°C (in comparison with 813° in the control sediment) indicates disintegration of the talc layer of the chamosite.
Figure 8. Samples from chamosite and montmorillonite with iron- and sulphur-rich spherules. A – nauplius from the chamosite (on a copper support) with Fe-S spherules. B – enlarged portion from A showing spherules. D, E – the same from the montmorillonite. Note the spherules (whitish dots) in D scattered all over the surface. C, F – Elemental content of the spherules (SEM/EDX analysis at 20 kEv, values are atomic percentages): C – from the chamosite, F – from the montmorillonite; Fe/S atomic ratio is about 1:3.
Figure 9. Deposition of aluminium on multicellular and unicellular organisms detected by fluorescent dye lumogallion (emission at 488 nm, green). A-C – sponge Spongilla lacustris: A – autofluorescence, B – lumogallion-stained Al-negative control, C – lumogallion-stained Al-positive experiment. D-I – flagellateEuglena gracilis : D – autofluorescence, E – Al-negative; F – Al-positive; G, H, I, - the same under a confocal microscope to show intracellular localization of the fluorescence-emitting organelles. J-P – social amoeba Dictyostelium discoideum; all samples were stained by cellular Hoechst dye to locate the cells; in each pair or images (e.g., J’, J) the first image (in this case, J’) shows fluorescence at 409 nm (Hoechst dye), while the second image (in this case, J) shows fluorescence at 488 nm (lumogallion). J, L, N – unicellular amoebae; J – “autofluorescence” (Al-negative, no lumogallion staining), L – lumogallion-stained Al-negative control, N – lumogallion-stained Al-positive experiment. K, M, P – multicellular fruiting body; K – “autofluorescence”, M – lumogallion-stained Al-negative control, P – lumogallion-stained Al-positive experiment. O – multicellular culminant, lumogallion-stained Al-positive experiment. Fluorescence is bright green only in Al-positive multicellular stages (O and P), implying that only multicellular stages absorb aluminium from the medium. Scale bars C-F, K, M, O, P – 100 µm, G-I, J, L, N – 20 µm.