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- For approximately 15 years, our laboratory has been working on various aspects
of Late Permian (~250 million years ago) and Middle Triassic (238 myr) floras
from Antarctica. The best of these floras is anatomically preserved, so that
every cell within the plants is intact, a preservation process called
permineralization. Permineralized deposits are the rarest form of plant fossil
preservation and can reveal a great deal of information about anatomy,
morphology, and reproductive biology, as well as plant-animal and plant-microbe
interactions in the ecosystem. In addition, the floras from Antarctica are
particularly important since we know very little about the plants that lived
during the Permian and Triassic, due to generally poor preservation of floras
elsewhere in the world. During these time periods a number of unusual seed
plant groups evolved, several of which have been implicated as possible
ancestors of the flowering plants (angiosperms), the group that dominates the
world today.The availability of anatomically preserved material from these
groups has furthered our knowledge of seed plant evolution in the late
Paleozoic and Mesozoic considerably.
This research has already produced significant results including:
-The oldest, anatomically preserved fossil cycad (Smoot et al., 1985) and
associated pollen cone (Klavins et al., 2003)
-Evidence of polyembryony in Permian seeds (Smoot and Taylor, 1986)
-Two standing fossil forests which grew at very high paleolatitudes
(80-85º S in the Permian; 70-75º in the Triassic) (Taylor et al., 1992; Cúneo
et al., 2003)
-Anatomically preserved reproductive organs of the Permian seed ferns,
Glossopteridales (Taylor and Taylor, 1992) and associated stems and leaves
(Pigg et al., 1990, 1993)
-The discovery that Triassic Dicroidium-type leaves were borne on
different stem types in East Gondwana and West Gondwana (Meyer-Berthaud et al.,
1993)
-A completely new group of Mesozoic seed ferns, the Petriellales, which
show some characters similar to the flowering plants (Triassic) (Taylor et al.,
1994)
-Triassic specimens of Osmunda, the "interrupted fern," which appear
almost identical to modern forms (Phipps et al., 1998)
-Data on paleoclimate in Antarctica based on fossil tree rings, indicating
that the poles were warmer than has been suggested from physical paleoclimate
models (Taylor et al., 2000)
-The first evidence of the attachment of Dicroidium fronds, the most
common leaf type in the Triassic of the southern hemisphere, to stems that also
bear seeds in cupules (Axsmith et al., 2000)
Website: http://paleobotany.bio.ku.edu/default.htm
[Summary provided by the University of Kansas.]
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