OT Cycads not ‘living fossils’

Gary Meltzer tropicalsea3@gmail.com
Thu, 24 Nov 2011 15:46:35 PST
Gee whiz David, you ruined my day!  I usually refer to my cycad seeds as
Jurassic corn-nuts (this won't make sense to members outside of the U.S.
probably).  Now I have to find a new term for them.

Dinosaurs may not as a rule feasted on the fruits alone, but as a
bi-product of grabbing a mouth full of plant and inadvertent swallowing
them.  The spread of seed would be through browsing migration and
deposition.  Not unlike the dodo that is given credit (in question) for the
dispersal of Sideroxylon grandiflorum in the same manner.


P.S. Thank you for posting this information.

On Thu, Nov 24, 2011 at 12:15 PM, David Ehrlich <idavide@sbcglobal.net>wrote:

> From Science News  http://www.sciencenews.org/
> Once thought to be the last remaining members of a plant lineage that went
> extinct with the dinosaurs, modern-day cycads are now believed to have
> diverged
> from a more recent common ancestor.
> Although cycad populations suffered major losses about 65 million years
> ago when
> dinosaurs — their once primary dispersal agents — went extinct, the plants
> later
> experienced a renaissance due to a global climate shift, a new study
> suggests.
> Living cycads diverged from an ancestral species that flourished around 12
> million years ago, not from older dinosaur-era relatives, an international
> team
> of researchers reports online October 20 in Science.
> To estimate the divergence time of living cycads, researchers used a
> technique
> called molecular clock analysis. First they measured the genetic
> differences
> separating 200 living cycad species. Since certain genetic changes
> typically
> accrue at a fixed rate once species radiate from a common ancestor,
> scientists
> were able to use this cycad DNA data, in conjunction with the fossil
> record, to
> predict a much more recent divergence. – Nick Bascom
> My take -- one doesn't usually think of dinosaurs deftly plucking seeds
> from a
> cone to enjoy the fleshy aril; that's something a bird or small mammal
> might
> do.  I wonder what the cycads were like that depended upon dinosaur
> dispersal.
> David E.
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