Red blood cell remains streamed out of a Carboniferous human femur
fossil
Here is the labelled photo:
http://www.wretch.cc/album/show.php?i=lin440315&b=21&f=1834688088&p=72
The unlabelled photo is right next to the labelled one.

Note: The other day I was looking under an optical microscope for
fossilized red blood cells in a thin section cut from a Carboniferous
human femur. Suddenly, I noticed a pool of red blood cell remains.
Outside the pool, I found some more red blood cell remains.
They seemed to be in a stream. I followed the stream upward and, to my
surprise, found a broken blood vessel remains which originated from a
Haversian canal. I think the red blood cells streamed out of the blood
vessel when the thin section was cut from the Carboniferous fossil and
ground. Afterwards, I realized this was nothing new, as Dr. Mary H.
Schweitzer had discovered the same thing from a femur specimen of T.
Rex. The difference is that my specimen came from a Carboniferous
human femur. I believe many such cases will be found in my specimen,
as many Haversian canals in the thin section are filled with red blood
cell remains. I once asked the operator of SEM to look for RBC in the
Haversian canal, but he gave me an unbelieving look and ended the
search in a short time.