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Re: Mid Jurrassic Angiosperms?



Michael J. Styzen wrote:

>I just read an article from the April 3 issue of Science.  The author,
>Dong Ren, discusses fossils of apparently nectar eating flies from the
>Late Jurrassic of Asia.  He considers this to be evidence that
>angiosperms arose in the Middle Jurrassic and were flourishing by the
>Late Jurrassic.  If this is so, maybe dinosaurs were munching flowers
>much earlier than we thought.

The flies in Dong's paper come from the Yixian formation, the same one that
is the source of Sinosauropteryx, Confuciusornis, et al. He takes the
Chinese dating of the formation as late Jurassic to be correct. Other dates
are much younger. Josh Smith cited 121.9 million years a few messages back;
a Canadian group got a similar result, although questions ahve been raised
about whether they may have sampled rocks intruded into the formation after
the fossils were deposited. Other fossil evidence is consistent with an age
around 120 million years.

In short, that paper is _not_ solid evidence that angiosperms were common
in the late Jurassic. It does indicate once again the importance of pinning
down solid dates for those extremely important Chinese fossils.

--Jeff Hecht