Umkomasia sp.
Geological Time: Triassic
Size (25.4mm=1 inch): 30 mm across on a 45 mm X 70 mm matrix
Fossil Site: Mount Piddington, Victoria Pass, New South Wales, Australia
Fossil Code: AAF206
Price: Sold
 Description:
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 known nomenclature. The female reproductive structures
were of the Umkomasia type, while the male pollen-bearing structures
were termed Pteruchus (see my other offerings). They serve as important
index fossils, and some data indicates 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 large pair of star-shaped fruiting bodies a most desirable
example. |
