Disneyland’s Pirates of the Caribbean was built in 1967 and was the last ride Walt Disney himself supervised. At the time, they thought that fake skeletons didn’t look scary enough so they contacted the UCLA medical department and were able to get the real deal. Over time as people became aware and technology improved they replaced most of the human remains with fake props.
Disney claims that they gave the real skeletons proper burials.
So for a time when your kids were going through the ride they were seeing real remains from dead human bodies for entertainment.