interesting way the pretorians carry theirs Scuta

[TraderTrey9785]

I agree, in the relief it does look like a leather strap similar to a hoplon. However, I had read somehwere that legionaries didn't carry their scuti in a hoplon fashion, with their arm horizontal, but rather vertical (easier for carrying on long marches). I couldn't find the original article, and someone please correct me if I am wrong. I wouldn't think Preatorian would carry their shields in any different manner unless they were designed for a cavalry unit of some kind. I agree with Theo, seems to me it is some sort of dismounted cavalry.