Ginkgoites
simmondsi
Dicroidium odontopteroides
Geologic
Time: Early Late Triassic (Carnian Stage)
Size (25.4
mm = 1 inch): Ginkgoites: 37 mm by 83 mm Dicroidium: 105 mm by 45 mm
Matrix: 165 mm X 100 mm
Fossil Site: Dinmore, Queensland, Australia
Fossil Code: AAF577
Price: $165.00
- sold
Description:
This plaque displays a fine example of a leaf from Ginkgo-like tree
with fine preservational details. This one comes from an old collection;
the disused quarry is no longer accessible. This is a fine example
of the preservation for which this biota is known. The Ginkgophyta
probably originated about the same time as the Cycads during the
late Paleozoic. The fan-shaped leaves of most members are quite
distinctive. This one is atypical, with deeply dissected leaves.
Gingko biloba is the only extant member. It is seen in association
with a fine example of a seed fern known as Dicroidium, with the
reverse a mass of Dicroidium leaves and fragments. Corystosperms
or fork-leafed seed ferns are a group of extinct plants with mostly
fern-like
foliage but with real seeds found in the Southern Hemisphere lands
of Gondwana. The flora of Gondwana evolved in isolation from the
rest of Pangaea because of an arid desert that persisted near the
equator. The seed fern Dicroidium, like Glossopteris, was found
throughout Gondwana, and helped lend credence to the theory of Continental
Drift. They possessed elaborate reproductive structures which had
their own nomenclature. They serve as important index fossils, and
some data indicate that they may have persisted into the Cretaceous
when the angiosperms first made their appearance. Few are ever listed
for sale—Triassic plants are rarely available, making this
a desirable specimen from either side.
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