CHEN, JUDY IJU. Florida Museum of Natural History, Dickinson Hall, PO Box 117800, Gainesville, FL 32611-7800. - Middle Eocene palynoflora of Huadian, Jilin Province, Northeastern China.
The fossil flora of Huadian, Jilin Province, provides an important
datum as the first independently dated Middle Eocene flora from
Northeastern China. Its occurrence in association with Middle Eocene
mammalian fauna invites comparison with Middle Eocene floras in other
parts of the Northern Hemisphere. Several megafossil plants have been
reported, and work on palynoflora is now in process. The Huadian
locality contains oil shales overlain directly by siltstones. The
fossil mammals were found exclusively in the oil shale layer, but all
the megafossil plants were found only in the siltstone. Comparison of
palynoflora from both layers will gain a more correct dating about the
plant megafossils. Both light microscope and SEM images are essential
for describing fossil palynofloras however most prior work on pollen
of Eocene East Asia was based on light microscope only. To describe
the fossil pollen types in more detail, I photograph the same isolated
pollen grains under both light microscope and scanning electron
microscope. This complete documentation is important for correct
comparison of palynoflora among different localities. Abundant pollen
grains were recoverd from the overlying siltstone layer, with at least
10 different kinds of pollen type found so far, including
Taxodiaceae-, Tiliaceae-, Betulaceace-, and Fagaceae-like pollen
types. In general, Angiosperm pollen is dominant in the palynoflora,
much less conifer or fern spores are found. Less abundant pollen
grains were recovered from the oil shale, and the pollen type hasn’t
been identified yet. The palynoflora, together with megafossils from
the same locality, provide insight into the middle Eocene environment
of Northeastern Asia. Comparison of the Huadian and other similar age
floras of NE China with those of other middle Eocene localities in
North America and Europe may reveal the phytogeographic origin of some
taxa which were widely spread once but now endemic to China.
Key words: Eocene, Huadian, palynoflora, pollen