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Re: Dinosaur trackway questions



Title: Re: Dinosaur trackway questions
In a message dated 2/14/02 2:26:58 PM Pacific Standard Time, emmar@ldeo.columbia.edu writes:


<< Coombs' swimming theropods:
there's NO reason to think these are NOT undertracks (I've spent a considerable amount of time on my hands and knees on that very surface). (Sorry Rich - IMHO these are NOT 'convincing' swimming tracks) >>

      WHY are they not 'convincing' swimming tracks? WHY no reason? Supposedly swimming sauropod trackways (manus prints only) have also been dismissed as undertracks, but I've only heard the dismissals. What have you discovered in your observations, or must I wait for the paper? DV

see: Farlow, J. O., and P. M. Galton. in press, Dinosaur trackways of Dinosaur State Park, Rocky Hill, Connecticut. In LeTourneau, P. M. and P. E. Olsen (eds.), The Great Rift Valleys of Pangea in Eastern North America, vol. 2: Sedimentology and Paleontology. Columbia University Press).

I agree with their analysis.....
If you look at deep undertracks, in cases where you have the 3D recorxd of the track (ie a thick slab that has been sliced through at diff. layers) you end up, deep down, w/ essentially the same morpholopgy as you see at Rocky Hill (Coombs 'swimming tracks'). Now, please enlighten me, if a dino is swimming and its toes grazing the bottom.....how do the aforementioned toes 'graze' through, in these 3D cases, 6 inches or more of soft sediment?

----
Emma C. Rainforth
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