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Re: arctometatarsus paper

Snively et al. use these as their conclusions:

  "1. Description and shape analyses indicate that the arctometatarsus is
morphologically distinct from other theropod metatarsi but variable in
some details of form and thus function between tyrannosaurids,
ornithomimids, troodontids, and caenagnathids.
  2. Differences between arctometatarsalian morphologies are consistent
with homoplasy, revealed by independent character evidence (Sereno, 1999;
Holtz, 2000; Clark et al., 2002) and best documented by Holtz (2001). The
present study suggests a minimum of four origins. The structure?s
developmental expression was possible in coelurosaurs but apparently not
in other theropod taxa.
  3. Proximal intermetatarsal ligaments were probably a prerequisite to
the developmental cascade responsible for the arctometatarsus (including
the appearance of extensive distal ligaments).
  4. If the arctometatarsus enhanced agility, its probable selective
benefit was likely related to predatory performance in carnivorous taxa.
Biological roles associated with intra- and interspecific competition and
escape were probable at various stages in a possessor?s life history."


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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