Re: archosaurian matters

[Tom Holtz <tholtz@geochange.er.usgs.gov>]

>When the MOR first put out a press release on this about a year
>ago, it was stated that these possible "red blood cells" appear to
>contain a "nucleus". Does MOR still think they have blood cells?
>
>Bird's red blood cells have a nucleus, but some other higher
>vertebrate's red blood cells lack a nucleus (such as our red blood
>cells).  If anyone out there has up-to-date journal references
> or any other references on the occurrence of nuclei in red blood
>cells of other taxa (such as crocodylians), I would be interested
>in them.  Thanks.
>

Last I heard, Schweitzer et al. still considered them "potential blood
cells".  Also, "higher vertebrates" do not have non-nucleated red blood
cells, mammals do ;-)  (Loss of nuclei in red blood cells characterize
mammals, while the sauropsid [bird, "reptile"] lineage retained them).

                                
Thomas R. Holtz, Jr.                                   
tholtz@geochange.er.usgs.gov
Vertebrate Paleontologist in Exile                  Phone:      703-648-5280
U.S. Geological Survey                                FAX:      703-648-5420
Branch of Paleontology & Stratigraphy
MS 970 National Center
Reston, VA  22092
U.S.A.