Grass phytoliths found in dinosaur dung

[peter.stevens at MOBOT.ORG]

I am not a grass person, but some possible dates include 89 mybp fopr stem
group Poaceae, 83 mybp for crown group Poaceae, the two major clades
(PACCAD, BEP, first letters of subfamilies) around ca 55 mybp, 12.5 my for
widespread development of taxa with the C4 photosynthetic system, a fossil
Programinis from Burma 110-110 mybp.  A certain amount of not adding up....

P.



Dear All,
      Been a while since I touched on this subject here (see grasses and
gondwana thread, 20 June 2002).  But we now have physical evidence
(coprolites) showing that some late Cretaceous dinosaurs ate grasses (and a
variety of types of grasses at that).  Not really surprising that this
occurred in India (being part of Gondwana back in the Mesozoic).  As I said
back in 2002, gondwanatheres (mammals) probably ate grasses too, and their
molars indicate that they may have even specialized in eating grasses.  But
dinosaurs probably just ate grasses when something better (without
phytoliths) wasn't available.


     However, I haven't seen the actual paper, so I'm still not sure what
was meant when these grasses were described as "highly evolved" types.  Does
this mean "highly evolved" (derived) subfamilies of Family Poaceae?  Or does
it mean derived families of the Order Poales (including families closely
related to Poaceae)?  Anyway here is a link to one news item:


  <http://www.newscientist.com/article.ns?id=dn8336>
http://www.newscientist.com/article.ns?id=dn8336


        -----Cheers,
                  Ken Kinman