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Re: possible ceratopsian feeding behaviour?



REPLY: I totally gree with your elucidations below --
and the similar framework sent to me by Dann Pigdon --
noting the differentiations between grazing (like
Dann, I see ankylosaurs as grazers, perhaps some
subadult hadrosaurs) and browsing (ceratopsians, some
sauropods). However, I was speaking in broad
generalities, not in any specificity re: grazing and
browsing. I believe that environmental stresses caused
the ceratopsians to be able to displace sauropods,
derived as well as from the biomass of the animals (a
long sauropod could not navigate its way very well in
an evergreen woodland). Although not having thought it
out yet vis-a-vis the literature, it could very well
be that sauropods may have starved to death in certain
regions, i.e., with their rostrally narrow beaks and
shear-like jaws, ceratopsians were able to tear up, as
it were, and swallow foliage perhaps poisonous to the
sauropods. Plant toxic defenses, an area wonderfully
analyzed in the work of Fred Provenza, could have been
prevalent during the transitional stages when
sauropods were driven from the ecosystems taken over,
as it were, by ceratopsians and hadrosaurs.
Another area worth considering: I have seen the
figures -- the actual amount of foliage involved in a
24 hour period -- for how it takes to keep an
elephant, or a giraffe, or a rhino (wildebeests, et
al.) alive. Using some adjusted mathematical formulae,
could not one reasonably estimate, e.g., the amount of
food intake that would be required by a sauropod, or
an ankylosaur, or a stegosaur, or a ceratopsian? These
multi-tonne animals were eating voraciously...but how
much? I have seen how a herd of rhinos can decimate
acres of plants, then would have nearly starved if
technicians at the San Diego Zoo had not quickly
realized what was happening and brought in bales of
foliage...which is a wonderful argument in favour of
making "zoos" breeding laboratories vs. "entertainment
parks", and making it a serious crime in Africa to
poach and kill (the gorilla is nearly extinct because
of the local population's greed). Is it not incumbent
upon us, as humans, to prevent the slaughter going on
in African fascist societies? Unless I am mistaken,
education, health care systems (including drastic
measures of birth control in light of the pandemics
there), housing (I am speaking of houses or apartment
complexes,  not grass huts), and the introduction of
African populations to the 21st century (denied to
them by manipulative governments), will effectively
stop the killing of animals because people will be
living in human population areas (they are called
"cities" or "townships"), and not in econiches
occupied by the animals. Having seen the "jungles" of
the Congo -- still virtually unexplored -- and knowing
they are teeming with undescribed, spectacular taxa,
it is a source of profound sadness to know much of it
may be eradicated.
Once the people are removed from these areas -- where
they should not be (the "noble savage" living in
squalor is a colonialist myth) -- perhaps
ecomorphological studies can be energetically persued
to ascertain if, among some mammalian taxa, there are
not analogues to the pre-K/T dinosaurs we are
speculating about.
Just a thought. And, Jaime, excuse the oratory above; 
it is a subject(s) I have profound concerns about.
Dinosaurily, Stephan
Philosophiae judaicae naturalis principia
dinosaurologica
--- "Jaime A. Headden" <qilongia@yahoo.com> wrote:
> Stephan Pickering (stefanpickering2002@yahoo.com)
> wrote:
> 
> <Unless I am mistaken, there was foliage of variable
> height during the
> late Cretaceous, and ceratopsians growsed/grazed on
> it. In other words,
> they were growsing grazers and grazing
> growsers...herbivores.>
> 
>   Grazing refers almost soley to cropping grass or
> short ground-covering
> vegetation, as in ferns or the like, close to
> ground, not just low-lying
> vegetation like small bushes. The trick here is the
> type of plant, being
> highly silicaceous modern grasses require
> specialized dentition
> (hypsodonty) with flattened, multi-lophed crowns for
> shreading bitten
> matter. Similarly, the front of the jaw and the
> teeth therein are largely
> trnasverse in orientation, allowing cropping to
> occur. An animal with a
> pointy snout cannot crop ground vegetation unless it
> held its head
> sideways to it, which it both impractical (risky to
> survival and
> excessively wasteful of evergy and time) as well as
> anatomically
> impossible -- it would have to lie down to do this
> in any event, and
> grazers must keep moving to eat ... silicacous grass
> does not offer much
> in the way of nutrition. Ferms do not occur in large
> enoguh patches the
> modern world enough to infer they could in any
> extinct ecosystem, and no
> fossil discoveries support large swaths of group big
> enough to support
> several multi-ton animals without proving completely
> ineffective at
> managing a biomass. Grass is silicaceous
> (resistance), fast reproducing
> and growing, permitting it to be a viable food
> product, which is why in
> the Miocene grasslands became so prevalent.
> 
>   The jaws of ceratopsians are not designed for
> grazing, and this must be
> taken into consideration when inferring their
> ecology. There is a long,
> cropping/crushing beak in front, and a set of ample
> shears behind
> supported by a massive set of jaws, indicating
> ceratopsians regularly took
> on food that required much more mechanical effort to
> harvest than it did
> to process; the shears imply ability to render into
> sections, but not
> orally process as do grazers. Ceratopsians most
> likely had no means to
> process their food in their jaws. There are no
> extant large herbivores
> which live in closed, forested environments which
> have such a dentition
> like ceratopsians; this indicates at least that
> there are no extant
> analogues, unlike the so-called ungulate/hadrosaur
> analogues worked on by
> Janis and Caranno (together and separately).
> 
>   Cheers,
> 
> =====
> Jaime A. Headden
> 
>   Little steps are often the hardest to take.  We
> are too used to making leaps in the face of
> adversity, that a simple skip is so hard to do.  We
> should all learn to walk soft, walk small, see the
> world around us rather than zoom by it.
> 
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