Riddle of the Nautilus: Specific Structural Features of Its Shell
| Autor: | Alexey Veligzhanin, D. A. Petrochenkov, D. I. Frey, A. A. Chernyshov |
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| Rok vydání: | 2018 |
| Předmět: |
Calcite
Materials science biology Conchiolin Small-angle X-ray scattering Aragonite Shell (structure) Chambered nautilus 02 engineering and technology engineering.material 010402 general chemistry 021001 nanoscience & nanotechnology Oceanography biology.organism_classification 01 natural sciences 0104 chemical sciences Strontianite Crystallography chemistry.chemical_compound chemistry engineering Nautilus 0210 nano-technology |
| Zdroj: | Oceanology. 58:38-44 |
| ISSN: | 1531-8508 0001-4370 |
| DOI: | 10.1134/s0001437018010101 |
| Popis: | The shells of the chambered nautilus (Nautilus pompilius) are studied by X-ray structure analysis (XRD) and electron microscopy (SEM and TEM). The shell structure is examined in a nanometer scale using XRD and synchrotron-based small angle X-ray scattering (SAXS). The mineral composition of shells includes 98–99 wt % aragonite, ~1 wt % organic substance (conchiolin), 1 wt % strontianite, and 0.5 wt % calcite. Trace elements comprise Na, Mg, Al, K, Si, Fe, P, S, Zn, Sr, Ba, and Cl. The laminated layers are composed of aragonite crystals with a width of 5–10 μm and a thickness of 0.5–1 μm; the prismatic layers, with a length of 7–12 μm long and a width of 1–3 μm. According to XRD and SAXS assays, the aragonite layers are formed of flawless monocrystals lacking any internal structuring. The shell conchiolin is a polymer formed of a system of parallel fibers folded with a step of approximately 100 nm without longitudinal structuring. Presumably, the unique structure of the nautilus shells has determined the existence of Nautiloidea over 500 Ma and their preservation as fossils for over 100 Ma. |
| Databáze: | OpenAIRE |
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