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Hadro tails (was Re: My Gr. 9 Science Fair Project: Questions)

Paul Willis wrote (quoting Stephen Throop):

>>Crocs eat meat and swim fast with their big tails.  African herd mammals
>>eat plants and swim slowly with their hoofs.  Duckbills had big tails.
>>Does parsimony dictate that because they ate plants, they must have swum
>>as slowly as modern herd mammals?
>No, this would not be logical. But, just because hadrosaurs had deep tails
>does not mean that they were good swimmers. While a deep tail can be an
>effective swiming mechanism, it is unlikely that they evolved in hadrosaurs
>for this purpose.

Indeed!  Especially given the fact that, like many other ornithischians, the
base of the tail of hadrosaurids was reinforced with ossified tendons, so
that there would have been considerable restriction on lateral motion.

Thomas R. Holtz, Jr.
Vertebrate Paleontologist     Webpage: http://www.geol.umd.edu
Dept. of Geology              Email:th81@umail.umd.edu
University of Maryland        Phone:301-405-4084
College Park, MD  20742       Fax:  301-314-9661

"To trace that life in its manifold changes through past ages to the present
is a ... difficult task, but one from which modern science does not shrink.
In this wide field, every earnest effort will meet with some degree of
success; every year will add new and important facts; and every generation
will bring to light some law, in accordance with which ancient life has been
changed into life as we see it around us to-day."
        --O.C. Marsh, Vice Presidential Address, AAAS, August 30, 1877