Geology Reference
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Fig. 3.3
TEM sections of modern (
a
) and fossils (
b
-
g
) angiosperm leaves showing the wide variation
of internal organization of the fossils (both within and between taxa) and that with one exception
(
f
) fossils are not recognisable in terms of modern leaf tissues. (
a
)
Quercusrobur
; (
b
)
Populus alba
specimen 1; (
c
)
P. alba
2; (
d
)
Castaneavesca
specimen 2; (
e)
C. vesca
1; (
f
)
Quercushispanica
specimen 1; (
g
)
Q. hispanica
2. Scale bars 10
μ
m in all except b and e where they are 2
μ
m
recognisable in terms of modern leaves and can be interpreted as partially compressed
and distorted cell walls forming a cellular structure. However, in some places these
'cell walls' seem to intertwine and anastomose in a manner dissimilar to that seen in
modern cells. This we interpret as due to compression and distortion combined with
some separation of wall layers. In the light of the preservation seen in
Q. hispanica
1
the open texture in
Q. hispanica
2 and
C. vesca
2 might refl ect the original cellular
organisation and hints of cell walls might, arguably, be present. The two
Quercushis-
panica
leaves both have an open texture, although one is cellular and the other is not
both have similar leaf thickness (c. 50 and 43
μ
m). In contrast, for
Populus
and
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