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RE: Turtles and dinosaur predators (Re: Oviraptorids as Parrots?)



> From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
> dannj@alphalink.com.au
>
> On Sun, 05 Feb 2006 16:05:39 -0800 (pst), Phil Bigelow wrote
> >
> > OTOH, if tyrannosaurs ate _Basilemys_ at infrequent random
> > opportunity, it still could have had a major impact on the
> > _Basilemys_ population. Modern mega-tortoises (e.g., Galapagos)
> >  don't exactly breed like bunnies.
>
> Their slow reproductive rate may be an adaptation to island living, since
> only a certain number of animals can survive with the limitations of space
> and resources, and predation isn't really an issue. Had such large tortoises
> evolved in a larger landscape with actual predators (as they obviously did in
> the Cretaceous), they may have popped eggs out at an astonishing rate to
> compensate. Growth rates in such a situation may also have been markedly
> quicker than those of Galapogos tortoises.
>
Note: there were giant species of _Geochelone_ (subnote: possibly not a clade, 
but simply a form genus for whenever tortoises get
too big :-) on mainland North and South America during the Pleistocene, so 
however they dealt with it, bigass turtles can live with
real predators.

                Thomas R. Holtz, Jr.
        Senior Lecturer, Vertebrate Paleontology
Department of Geology           Director, Earth, Life & Time Program
University of Maryland          College Park Scholars
        Mailing Address:
                Building 237, Room 1117
                College Park, MD  20742

http://www.geol.umd.edu/~tholtz/
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