Re: Titanis walleri from Texas

[Jeff Hecht <jeff@jeffhecht.com>]

At 9:02 PM -0400 10/28/06, Nick Pharris wrote:
>Quoting Jeff Hecht <jeff@jeffhecht.com>:
>
>> According to my notes, dating based on the uptake of rare-earth elements (a 
>> new technique) was done on the Sante Fe River, Florida and Texas sites. In 
>> both cases, the Titanis fossils were mingled with fossils from both the 
>> Pliocene/early Pleistocene and the late Pleistocene. In Santa Fe, FL, the 
>> rare-earth element signatures matched those of 2 million year old mammal 
>> fossils. In Texas, the rare-earth signatures matched those of Pliocene horse 
>> fossils. That implies there is no evidence for late Pleistocene Titanis.
>
>And therefore, I take it, that the _Titanis_ remains found mingled with 
>Pleistocene fossils were reworked?
>
That's what they imply. They state that the fossils from the two periods were 
"temporally mixed" at both sites, and they tried the rare-earth technique to 
figure out which period the Titanis fossils had come from. They didn't describe 
the sites in detail, and I'm not a geologist, so I don't know how the mixing 
took place. 
-- 
Jeff Hecht, science & technology writer
jeff@jeffhecht.com  http://www.jhecht.net
525 Auburn St., Auburndale, MA 02466 USA
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