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Re: a little background



Graydon (graydon@dsl.ca) wrote:

<Dromaeosaurs are set up to attack *bigger* stuff; troodontids seem to be
crepuscular and set up to go for *smaller* stuff.  There doesn't seem to
be a good wolf analog (taking deer about its own size); everything seem to
be either lions (ganging up on same size or larger animals) or foxes
(taking nothing much above half its own size.)>

  Evidence for dromies attacking bigger things than themselves is
supported only through circumstantial evidence in the Antlers and Cloverly
Formations, and the association of GI 100/25 and GI 100/26, a
*Velociraptor* and *Protoceratops* where the protoceratopian would only
have been about 175% the mass of the dromaeosaurid. Otherwise, no other
data can be used to support the idea that dromies were specialized to
large prey. Troodontids are even more problematic since you only have some
anatomy to go off, and no actual material data to indicate what they ate,
when they ate, etc. Diurnal owls and bats still have huge eyes, and large
eyes are true for birds generally, not just low-level-light feeders.

<Also, dromaeosaurids don't seem to be faster than the small bipedal
herbivores; they're supposedly sprint-and-seize-and-slash types.>

  Yeah, dromies typically have tibiae not that much longer than their
femora, but what's really cool is that the metatarsus is much shorter than
expected in a sprinter. Same for oviraptorids. It seems plausible to
suggest more ambushing-like attacks for the dromaeosaurs based on limb 
design....

=====
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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