https://www.cnet.com/news/egyptian-bird-hawk-mummy-turns-out-to-be-human-fetus/

A mystery over 2,000 years old that scientists didn't even realize was a mystery is unveiling new layers. 

The Maidstone Museum in the UK has an unusual Egyptian mummy dating from the Ptolemaic Period in its collection, where it was originally listed as a mummified hawk. A CT scan in 2016 revealed it was actually a human fetus, but the scan lacked details.