[Taxacom] Panamanian land bridge

[Ken Kinman]

Dear All,
     In some recent news, the terror-birds of North America are apparently 
older than once thought.  The youngest are apparently 2 million years old 
(not a mere 10,000 years or so), and they probably went extinct much earlier 
than generally believed.

      But even more interesting is that that oldest known terror-birds in 
North America are around 5 million years old, which is a couple of million 
years before the Panamanian land bridge is thought to have become 
continuous.  If so, is the most likely explanation that (1) the continuous 
land bridge formed earlier than we thought, or (2) were terror-birds good 
enough swimmers (or rafters) to island hop before a continuous land bridge 
was formed?  A little food for thought.
    -----Cheers,
           Ken Kinman

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