Dinosaur-dispersed cycads

Steven hartsentwine.australia@gmail.com
Sat, 26 Nov 2011 02:35:29 PST
Parallel Evolution ! 
Cannot be ruled out.... But.....
Time has no boundaries & humans often find difficulty fathoming evelution verses time.

Not much finds cycad fruit too yummy, but  let's say hypothetically, even if they were not dispersed as a direct food supply.

A large carnivore chasing food through cycad groves,  may have a stride of 2 to several meters when running, also with a long tail swaying for balance & fast direction changes, like many modern day lizards, seeds could be easily spread over a very large area, & this could have been repeated countless numbers of times, for thousands or millions of years.

If you visit some of the cycad groves outside Darwin Australia, u often find a progression of seed dispersal in the degrading & collapsing rocky outcrops. Seeds easily fall to the flat sandy shelves & flooding rains flow them into extremely powerful waterfalls that can carry them for hundreds of kilometers.

Some other factors that might move seeds even further. There was far more geological activity going on millions of years ago, falts & uplifts of mountains, movement & dividing of continents, ice movement at edges of green pockets etc.

Personally I've been into dinosaurs for about 40  years & I believe animal dispersal is a bit fanciful, its more likely to have been from smaller mammals that lived along side the giants.

In far North Queensland it was discovered that Rat Kangaroos are responsible for up to 70 % of hard seed dispersal, happily moving seeds from the parent tree & burying them to store for the winter when food is less available. These seeds usually don't grow beneath the parent tree so they need a little help to multiply. The Rat Kangaroo only finds 30% of the seeds they bury & the survival of the other 
70 % is insured. 

To back up this theory in part,  I would ask, if dispersed by dinosaurs, how do we explain cycads in areas of the world where dinosaurs did not rein.

There is an interesting spanner in the works !


On 26/11/2011, at 7:08 PM, Mark BROWN <brown.mark@wanadoo.fr> wrote:

> Rachel,
> The PDF link for the original paper in the article you refer to does not work.
> Do you have acces to it otherwise or anyone else?
> One comment on the synopsis first refered to here was to the effect, how could a group of plants that is only 12 millions years old be found in such widely dispersed sites around the globe? I wonder too?
> Mark
> " Message du 26/11/11 04:47
>> De : "Rachel Fitzhardinge" 
>> A : pbs@lists.ibiblio.org
>> Copie à : 
>> Objet : Re: [pbs] Dinosaur-dispersed cycads
>> You may want to look at this: http://rbgsyd.nsw.gov.au/welcome_to_bgt/…
>> Rachel
> "
> _______________________________________________
> pbs mailing list
> pbs@lists.ibiblio.org
> http://pacificbulbsociety.org/list.php
> http://pacificbulbsociety.org/pbswiki/
pbs mailing list

More information about the pbs mailing list