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268
Unfortunately, no absolutely indisputable evidence can be brought
forward to prove that all the above-mentioned coniferous remains
of different geological ages belong to or are closely related to the
recent genus Sciadopitys, the paleobotanical material here as often
being too incomplete. Much speaks, however, for the correctness
of this opinion. That Sciadopitys tertiaria not only belongs to
the recent genus but is nearly related to Sciadopitys verticillata,
I consider beyond all doubt. Further I have mentioned a species,
Sciadopitytes macrophylla, from Andö, which entirely agrees with
the recent genus in respect of the morphology of the epidermis
and the stomata of the double needles. Unfortunately no remains
of strobili of the jurassic species have been discovered. This is also
true as to the other species of Sciadopitytes, of which only remains
of double needles have hitherto been found. The latter forms also
agree well on the whole with Sciadopitys in regard to the mor-
phology of the symphyllodium, the under stomatiferous as well as
in most cases the upper non-stomatiferous groove being distingui-
shable. The paleobotanical material here referred to is thus, accord-
ing to my opinion, of value for the problem of the geological
history and phylogeny of the recent genus Sciadopitys.
The vertical as well as the horizontal distribution is very peculiar.
The following geological horizons are represented: upper tertiary
(upper pliocene), middle tertiary (upper and lower miocene),
middle cretaceous, lower cretaceous, upper jurassic, middle jur-
assic and upper triassic (rhaetic). The oldest known species is
Sciadopitytes scanica from the rhaetic of Scania. In the middle
jurassic conifers existed, similar to Sciadopitys, in northern Norway.
Species of upper jurassic age are mentioned from northern Norway,
Spitzbergen and Scottland. The lower cretaceous as well as the .
middle cretaceous is represented by species from Greenland. Ter-
tiary species are recognized from western Germany and Silesia.
The genus Sciadopitys evidently disappeared from Central Europe
together with many other asiatic types as a consequence of the
climatic deterioration, characterizing the beginning of the quatern-
ary period and causing the glaciation of Northern Europe.
It is of great interest to compare the probable geological history
of Sciadopitys with that of Ginkgo. The earliest ginkgophytes are
found in the triassic. In the middle jurassic their culmination —
the greatest number of species — seems to have been reached.
The Sciadopitineae probably reached their culmination in the lower
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