Follow-up: in July last year I wrote about a giant vertebra that had been found in a lake in northern Sweden at 210 meters above sea level. The find spot hasn't been near the sea since the end of the latest ice age. This meant that the bone might be very old.
But already in October there was news in the matter. Zoologists determined that the bone belonged to a sperm whale, and a radiocarbon analysis pegged it at only about 100 years of age. So during the big whaling era someone took the vertebra to the lake and threw it in.
Yup. That's what I would do if I found a sperm-whale vertebra.
An alternative explanation is that aliens abducted a sperm whale as a temporary experimental subject, and made a terrible mistake when attempting to return it to its natural environment.
I think they used a Saturn rocket as a rectal probe on the whale.