Re: Many critters have necleated r.b.c.'s

[Thomas_R_HOLTZ@umail.umd.edu (th81)]

J. H. Mahaffy wrote:

>
>If I remember right (and I do try and teach Zoology) a lot of critters
>have nucleated red blood cells.  I know birds and amphibians do and I
>suspect reptiles do to (although I did not check).  There are some
>differences in non mammalian physiology.  Although I think I recall that
>birds DNA in their nucleus is largely shut down, so it may not be that
>different physiologically than a non nucleated mammalian r.b.c. (but now
>you are treading on my foggy memory).
>
>-- 
Dr. Mahaffy's memory is correct - sauropsids (reptiles and birds) have
nucleated r.b.c.s  Lack of nuclei in red blood cells seems to be a mammalian
synapomorphy.



Thomas R. HOLTZ
Vertebrate Paleontologist, Dept. of Geology
Email:Thomas_R_HOLTZ@umail.umd.edu (th81)
Phone:301-405-4084