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RE: Floating allosaurs?? (sort of...)



At 12:16 PM 26/01/01 -0800, Nathan Myhrvold wrote:
Terrestrial animals that make it to remote islands like the Galapagos are
good example - the best current theory is that the got there by riding
natural rafts of storm debris (fallen trees etc.).   The number of founding
individuals is estimated to be very small, because it is a freak random
event that any make it all all.

Until driven extinct in the 19th century, there were many islands with giant
tortises besides the Galapagos - particularly in the Indian Ocean.  The
island of Aldabra still has them.   Tortises seem to raft well, and can
survive without water for a while which makes them good candidates.

The current wisdom about giant tortoises on both the Galapagos and the Indian Ocean Islands is that they did not get thereby rafting, but by swimming. Tortoises float extremely well, particularly if they are already large animals, and the evidence seems to be that these turtles were giants before they headed out to sea.



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Ronald I. Orenstein Phone: (905) 820-7886
International Wildlife Coalition Fax/Modem: (905) 569-0116
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