More trackway questions...

["Jordan Mallon" <j_mallon@hotmail.com>]

With all this talk going on about dinosaur trackways and running speed these 
days, I decided to check out one of the latest papers written on the 
subject:

Day, J. J., D. B. Norman, P. Upchurch, and H. P. Powell.  2002.  Dinosaur 
locomotion from a new trackway.  Nature 415: 494-495.

In it, the author's state, "This [zig-zag] pattern contrasts strongly with 
the more usual narrow-gauge form of theropod trackway in which 
pace-angulation values range between 160 degrees and 170 degrees: the 
hind-foot impressions are located close to the midline of the trackway."
Now, I've always read that most recovered dinosaur trackways indicate 
animals walking at moderately slow speeds, as evidenced by the relatively 
smaller pace lengths and pace angulations.  But according to this paper, 
trackways in which the foot prints are left close to the midline are most 
common, which, as I understand it, indicates a speedy animal.
What's the deal?

Jordan Mallon

http://www.geocities.com/paleoportfolio/

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