I seem to remember reading that the pyramid bow design was North American in origin. Can't remember the source.
As for longbows, I talked to Hugh Soar about this once. As I recall, he said he and other archer historians reckoned the shape of the
longbow was British (and very possibly Welsh - please note, one is a subset of the other [1]) in origin, and the idea of using yew was taken from the Vikings.
[1] I once fielded a phone inquiry from a Welsh chap who was very insistent that he wanted to learn to shoot the "Welsh
longbow". I mentioned the British Longbow Society and he got very huffy. I tried to keep things light by reminding him that the Welsh were British before the English were and his tone became rather aggressive. Nothing like a Nationalist who doesn't know his own history...