Bones, Dry Bones

 So, there's a lava tube in Saudi Arabia which is full of bones.

Some of these bones are 7,000 years old.

Some of them are human.

The culprit? Hyenas, who like to collect and stash bones and don't always do anything with them. Judging by the growling, they're still at it.

The cave, Umm Jirsan, promises to provide useful information as bones generally don't preserve well in the desert.