The THINGS you find in amber...

[kayshapero]

From LiveScience

Fossilized Tick Reveals Perfectly Preserved Red Blood Cells
By Tia Ghose, Senior Writer | April 4, 2017 10:18am ET

The only known example of ancient mammalian red blood cells preserved in amber may exist, thanks to a bit of monkey business.

The cells were found in a fossilized tick that had been gorging on a blood meal when it was unceremoniously removed midfeed and plunked in sticky amber. A subtle feature on the tick's back suggests that an ancient monkey that was grooming one of its friends removed the tick.

"Two tiny holes indicate that something picked a tick off the mammal it was feeding on, puncturing it in the process and dropping it immediately into tree sap," study co-author George Poinar Jr., an amber expert and professor emeritus at Oregon State University, said in a statement.
(more)

Not only RBC but a batch of parasites and things - see the rest of the article.