Re: Sauropods and Cycads??

[Keith90291@aol.com]

According to "Cycads of the World" by David L. Jones (Smithsonian Institution 
Press, 1993), it may be difficult to characterize Cretaceous cycads.  He 
lists the fossil record as:

Lower Permian
    China
Triassic (otherwise unspecified)
    Anarctica
    Argentina
    Arizona, U.S.A.
    India
    New Mexico, U.S.A
    North Carolina, U.S.A.
Jurassic (otherwise unspecified)
    Greenland
    Scotland and England
Eocene
    Alaska, U.S.A.
    Australia
    Japan
    Louisiana, U.S.A.
    Mississippi, U.S.A.
    Tennessee, U.S.A.
Upper Eocene or Oligocene
    Puerto Rico
Oligocene 
    Australia
    Tasmania
Oligocene or Lower Miocene
    Argentina
Lower Miocene
    Chile

Oddly enough he doesn't cite Cretaceous cycads from anywhere else.  So, 
something may be amiss here.

As for the assumption that cycad leaves must have been hard to digest, it 
isn't necessarily so.  The species of the extent genera Chigua, Stangeria and 
Bowenia have leaflets that are much more like the leaves of hardwood trees 
than the stiff and waxy leaflets of, say, sago palms.  And the extant Zamia 
furfuracea has broad, flat spatulate leaflets (albeit of a texture that's 
earned it the common name of Cardboard Palm).  Both the Bowenia and Zamia 
genera extend far back into the fossil record.  Presumably, cycads were much 
more diverse in the Mesozoic (though the fossil record doesn't seem to prove 
it).  Among living cycads, there are nearly 200 species spread across 11 
genera.