Re: Gingko berries as evidence of dino sense of smell?

[Phil Bigelow <bigelowp@juno.com>]

On Fri, 04 Feb 2000 13:29:03 -0500 Dinosaur Interplanetary Gazette
<dinosaur@dinosaur.org> writes:

>One would conclude, however, that yer average neighborhood dino might
>just think that gingko fruit was the best-smelling, tastiest thing on
>the menu at the Sauropod Hilton.
>
>Has anyone considered this idea and used it to extrapolate to the
>sensory capabilities of our saurian friends?

Good question.  I seem to remember birds pecking at fallen friuts, and I
seem to remember observing deer eat the fruits.

But since the Ginkgophyta goes back into the Permian (pre-dinosaur time),
it is doubtful that the fruits evolved to be specifically desirable to
dinosaurs.

The bad smell of ginkgo fruit comes from butyric acid that is found in
the fleshy coat.  Butyric acid is found in both unripe fruit and "ripe"
(fallen) ginkgo fruits.  It is commonly believed that in most other
plants, high acid content (bitterness) in unripe fruits has evolved to
discourage vertebrates from eating the fruit  before it should be eaten. 
"I will drink no wine before its time" (Orson Wells).

Since the fleshy portion of ginkgo fruits NEVER "ripen" (they remain
bitter.....at least that's what I've read), it could be argued that the
fruits did not evolve to be eaten by vertebrates at any stage of the
fruit's development.

In _Ginkgo biloba_, fertilization within the ovules sometimes does not
occur until AFTER they have been shed from their parent tree.  Since
ovules and microsporangia occur on different trees, it is important that
a fallen unfertilized ovule be in proximity to a male source of
fertilization.  It is possible that the best chance that a ginkgo ovule
has to germinate would be for it to be deposited and fertilized near the
same grove that it came from.  Long distance transport in the gut of a
dinosaur could possibly be detrimental in this case.  Some botanists even
claim (with little evidence) that naturally-propogating modern ginkgo
forests may no longer be efficient.  Modern ginkgo groves seem to require
some measure of intervention by humans in order to efficiently propogate
(there are no wild stands).  It would be interesting to do a controlled
experiment and test to see if this is/is-not a myth!

                <pb>











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