Petr Hykš
Spectral comparison of dentin (white, porous material) & rock filling (dark fillings) of Plesiosauria inder. tooth (SEM-EDS*)
Special thanks to Daniel Madzia (identification help) and to Petr Gadas (photography & spectrometry help).
Plesiosaurus sp. tooth (most probably)
Locality: Brno - Hády quarry (Czech republic), age: Upper jurassic, oxfordian. Lenght: 10mm
The images were captured using an electron microscope. There is one point in each image indicating the area of interest, where the chemical composition was measured using spectrometry.
You can see two different materials - light colored, fossilised dentin and darker rock fillings. There is a siginificant difference in chemical composition of dentin and rock filling, since each of the two showed a different spectrum.
According to the spectral analysis, dentin is composed mainly of calcium, phosphorus and oxygen (white spectrum). Presence of fluorine may not seem any significant, but along with the other elements, fluorine is one of the key elements that form a mineral known as fluorapatite - Ca5(PO4)3F. This means that dentin is composed of fluorapatite.
On the other hand, the yellow spectrum shows that the darker material filling the pores in dentin are filled with material composed mainly of silica and oxygen. Most probably quartz grains - SiO2.
*SEM-EDS = Scanning electron microscope (backscattered electrons) & Energy dispersive spectrometry
Spectral comparison of dentin (white, porous material) & rock filling (dark fillings) of Plesiosauria inder. tooth (SEM-EDS*)
Special thanks to Daniel Madzia (identification help) and to Petr Gadas (photography & spectrometry help).
Plesiosaurus sp. tooth (most probably)
Locality: Brno - Hády quarry (Czech republic), age: Upper jurassic, oxfordian. Lenght: 10mm
The images were captured using an electron microscope. There is one point in each image indicating the area of interest, where the chemical composition was measured using spectrometry.
You can see two different materials - light colored, fossilised dentin and darker rock fillings. There is a siginificant difference in chemical composition of dentin and rock filling, since each of the two showed a different spectrum.
According to the spectral analysis, dentin is composed mainly of calcium, phosphorus and oxygen (white spectrum). Presence of fluorine may not seem any significant, but along with the other elements, fluorine is one of the key elements that form a mineral known as fluorapatite - Ca5(PO4)3F. This means that dentin is composed of fluorapatite.
On the other hand, the yellow spectrum shows that the darker material filling the pores in dentin are filled with material composed mainly of silica and oxygen. Most probably quartz grains - SiO2.
*SEM-EDS = Scanning electron microscope (backscattered electrons) & Energy dispersive spectrometry