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Croc growth (was RE: More about Erickson et al. 2004 and RE: Delayed "growth spurt" in T. rex)



> From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
> Phil Bigelow
>
> I still haven't had a chance to see the paper, but I've got a question.
> Did the authors compare the _T. rex_ growth curve with the growth curve
> of the salt water croc or the Nile croc?
>
> Considering that these are the only extant large archosaurian predators,
> and considering that we have good ecological data on these animals, it
> would have been the logical comparison to make.  And this is a case where
> a negative correlation with crocs would be just as informative as a
> positive correlation!
>
Although they didn't compare those per se in this paper, such comparisons
were made earlier in the context of Erickson & Brochu's 1999 (Nature
398:205-206) Deinosuchus growth paper. Modern and fossil crocs have long
extended period of growth, and non-determinate size. It would be nice to see
their Deinosuchus data replotted as mass vs. age rather than length vs. age,
though, to make it more comprable to the dinosaur plots.

So it has already been established that dinosaurian growth curves and rates
are NOT like those of living crocodilians or other non-avian reptiles.

                Thomas R. Holtz, Jr.
                Vertebrate Paleontologist
Department of Geology           Director, Earth, Life & Time Program
University of Maryland          College Park Scholars
                College Park, MD  20742
http://www.geol.umd.edu/~tholtz/tholtz.htm
http://www.geol.umd.edu/~jmerck/eltsite
Phone:  301-405-4084    Email:  tholtz@geol.umd.edu
Fax (Geol):  301-314-9661       Fax (CPS-ELT): 301-405-0796