Thinking about it, a mammoth would likely have been a terror, of a biological sort, if you'd met one back in the day. So I like it for both bioterrorism and petroglyph.
So I'm favouring MAMMOTH -> AFRICA -> something -> something.
Need a petroglyph link for one of the somethings, and an Arab link for both of them.
For now I think MARBLE and TEMPLE are my favourites, though the Arab links are pretty weak. Some even more tenuous possibilities would be:
- BERMUDA: it's a type of sail-rig, and Arab Dhows were a thing (though I think not bermuda rig).
- ROOT: As in cultural roots. Though if it's both ROOT and AFRICA I'd have thought "Arabic" would be a clearer version of the clue. Unless the 3rd word needs it to be "Arab".
- WELL: As in oil well, and oil production is big in many Arab states.
The others are Eagle, Brazil, Buck, Whip, Cross, Degree.