Fróðskaparrit - 01.01.1963, Síða 82

88
Fossil Metasequoia From Mikines, Faroe Islands
lapping from right and left produces the zigszag pattern
of the axes, which is so characteristic of Meiasequoia.
This is best demonstrated on the short shoots while the
remoteness of the leaves makes this pattern more indistinct
on axes of the long shoots. This pattern is the result of
twisting to right and left 45° of successive leaf pairs re«
arranging the decussate leaf pairs into the pseudoídistichous
manner.
The average dimensions of the Ieaves of the short shoots
are: length 8 mm, width 1,5 mm. The midrib of the leaves
on the one impressions is strong and shows one longi*
tudinal central groove on some of the best preserved
specimens (No. 11) (Pl. 2, fig. 3). On the impressions of
the opposite side of the leaves (commonest case) the midrib
is a slender protruding strand. The leaf blade is longií
tudinally striated (No. K) (Pl. 2, fig. 3) and on a few
of the well preserved specimens (No. 8) (Pl. 2, fig. 1) a
row of small grooves on each side of the midrib can be seen.
On these vegetative organs all the characters which were
described by Chaney (1951) are found, and they ensure
the determination of the species as Metasequoia occidentalis
(Newb.) Chaney.
On quite a few of the well preserved short shoots the
leaves are placed in such a manner that they form a large
angle with the axis. But, on some other specimens this
angle is considerably smaller. The present author does not
consider this to be an original characteristic but, in accord*
ance with his previous interpretation of this phenomenon
from the fluviatile Paleocene sediments in West Greenland
(B. Eske Koch, 1963), he regards this as a secondary
characteristic, caused by the stream flow during the process
of sedimentation. This is in the present case further confirmed
by the fact that these short shoots may show similar orien*
tations (No. 7 and L) (Pl. 1, fig. 2).
Metasequoia occidentalis (Newb.) Chaney occurs in the
entire Tertiary system. This species can not be used for