Geology Reference
In-Depth Information
Fig. 4.3
Electron
microscopy of cuticles of
fossil weevils from Enspel
and a modern weevil
Sitophilus zeamais
for
comparison. (
a
,
b
) SEM,
(
c
,
d
) TEM. (
a
,
b
,
d
) Fossil
weevil, (
c
) modern weevil;
(
a
) shows outer surface of
cuticle and (
b
) broken inner
surface of cuticle. (
c
,
d
)
shows outer exocuticle
and inner multilayered
endocuticle; in (
c
) the
exocuticle is thicker
and it has also been slightly
distorted during sectioning
giving an undulating
appearance. Scale bars:
10
μ
m in (
a
) and (
b
),
1
μ
m in (
c
) and (
d
)
Lignin preservation is in the form of guaiacyl units but no syringyl-related lignin
units were detected. Polysaccharide moieties detected include 2-methyl-2-
cyclopenten-2-one, 2,3-dimethyl cyclopenten-1-one and an unknown pyrolysis
product characterised by
m/z
68,79,93 fragment ions that is very likely derived from
polysaccharide (Bland et al.
1998
). Methyl indole, benzene and its alkyl derivatives
(C
2
to C
4
), napthalene and pristenes were also present in the pyrolysate.
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