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Encapsulation
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Encapsulation occurs when minerals form around an organism.
Late Miocene gypsum deposits in the Alba area in Piedmont, Northern
Italy
contain
dragonflies
(mostly larvae) entombed in
single clear gypsum crystals. The insects became trapped in
the gypsum as this evaporate deposit formed. The entombed insects,
like most inclusions in amber, are thinly lined hollow spaces
(Schluter, Kohring, & Gregor, 2003, p. 374).
Organisms may also
become entombed in microcrystalline material. The
Devonian aged Rhine Chert near the Aberdeenshire villiage of
Rhynie in Scotland represents an ecosystem near
a sinter terrace. The area was periodically flooded
with
silica rich solution from hot springs and geysers (Selden & Nudds,
2004, p. 52 and Kenrick & Davis, 2004, p. 24). Organisms
were permeated with silica and entombed before any cellular decay
could occur. Insects have also been found encapsulated in Miocene
aged onyx from Arizona (Grimaldi & Engel, 2005, pp. 49-50). |
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Bibliography
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Grimaldi,
D. & Engel, M.S., (2005). Evolution of the Insects.
New York: Cambridge University Press.
Kenrick
P. and Davis, P. (2004). Fossil Plants. Smithsonian
Books: Washington.
Schluter
T., Kohring, R., & Gregor, H-J. (2003). Dragonflies preserved
in transparent gypsum crystals from the Messinian (Upper
Miocene) of Alba, northern Italy. Acta Zoologica Cracoviensia,
46 (Supplement-Fossil Insects), pp. 373-379. Selden
P. & Nudds, J. (2004). Evolution of Fossil Ecosystems.
Chicago: The University of Chicago Press. |
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