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Re: sauropod behaviour speculations



Stephan Pickering (stefanpickering2002@yahoo.com) wrote:

<... without repeating myself, I insist that ongoing behavioural
strategies of observable taxa are excellent sources of extrapolation. The
mammalian taxa, of course, are not dinosaurs, but the extant theropods
("birds") are highly derived lineages, flying and secondarily flightless,
whose morphologies are not what one can use. Thus, we turn to the
mammalian megaherbivores who are in similar  econiches to the pre-K/T
dinosaurs for hints, so to speak, of probable parameters of behavioural
systems.>

  The problem here is the inferrence of metabolism in dinosaurs, which are
different from those of reptiles. Even in the light of studies that
support various therories of "unique" metabolic solutions to permitting
some dinosaurs, such as sauropods, an equivalent mammalian high and/or
stable metabolic rate or activity cycle, these are no more than
speculation, and give us little means to compare. This is also inherent in
the works of Carrano, and if these were being read carefully enough, other
work from Sepkoski, Janis, Farlow, Bakker, Carrier, Farmer, Ruben,
Hillenius, and Paul would elucidate the ability to extrapolate energetics
from _anything_ non-avian and extinct.
 
<I do not believe, e.g., that waddling ankylosaurs are mirror images of
later armoured mammalians,>

  Of course, all extant armored mammals are small, rooting insectivores or
herbivores, and those that were large were still slow herbivores, without
any insectivorous abilities. There is little comparison. The drawing of
comparisons of sauropod to elephants or hippos (large, ecologically
diverse animals with social abilities that have nothing to do with anatomy
and cannot, therefore, be inferred from the fossil record without
extraordinary preservation, and this is rare and not even in evidence for
sauropods) is just as easily an intuitive pratfall in that it employs
typical typological interpretations that are easily falsified or
demonstrate themselves as lacking proof.

<or that elephant/giraffe are mirror images of sauropods. However: the
elephant/giraffe, when one combines data of morphogenesis and
cardiovascular systems, do give one analytic tools.>

  Except that the cardiovascular system has constraints that in sauropods
have gone beyond the simple "It must have, because giraffes did" when
biomechanics and fluids in a gravity system are also coupled with the
cardiovascular or even pulmonary data, show that the giraffe model cannot
work without "inventing" new organs or unique vascular anatomy that enable
sauropods to live with their necks elevated from the shoulders.

<You ask: "what small sauropods in what habitats?" Well, consider: when
hatched a sauropod is not full-grown, and a small sauropod may have
adapted certain strategies of behaviour not needed when a multi-tonne
adult.>

  And your evidence for this or manner in which you can cause this to be a
reasonable paradigm is what? All large mammals today keep their young
close to them for a long time, not discounting possible sauropod
neglectful behavior to their young as suggested at Auca Mahuevo. This
supports the absence of any real interpretive scenario when using mammals
as a comparison. Using reptiles ... now, that involves the reptilian
"neglect" in most (but not all), and how these _very_ small young do in
fact live in areas their parents do not; examples include young varanids
which climb and their parents do not, crocodiles which live in the reeds
and then move to open water as they grow, with virtually no data on snakes
that are social or retain any attention to their young ... or otherwise.

  You brought up small sauropods in reference to hippos, and this is true
for hippos: the young stay with the parents, and we so far have no
evidence of sauropod young life that could either attest to or falsify
your
hypothesis. This is in itself not a bad thing, but you need to ask
yourself: "In what way do modern ecologies reflect on the past, and can
they be related to anything in the past?" Honestly ask yourself this with
the possibility you will discard _all_ your preconceptions. Then, "What
makes me think any paleoecology is similar to any modern ecology?" These
animals are far different from those of today, with animals of a size no
mammal on land has ever attained, or a diversity of body types. Think of
an ecology where a heard of ceratopsids would have to eat in, every day if
need be, and see that all other large mammals save the African elephant
are lone feeders or are aquatic and feed on a resource that is most the
epitomy of the word "plethora" and highly reproductive, not the case in
plants that would feed ceratopsians.

  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.

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)

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