Lorica Musculata made of Metal or leather?

[Urselius]

There is no way to respond to it. By your logic, If someone once used them sometime, somewhere, then the Romans could have used them too.

Precisely, though the logic is not mine - Aristotle would have recognised it.

But, in order to follow through with this line of reasoning you actually have to produce an extant example of a leather musculata. A medieval one will do. We know that metal ones were made during the classic revival of the Renaissance but I can't think of any leather ones.

But I am not trying to prove that Romans used leather muscle cuirasses, just that the idea that they could have done is neither impossible nor ridiculous.

Personally I think bronze and iron are more likely to have been used - but to dismiss the possibility of leather at our present level of knowledge is unhelpful. Always keep an open mind until the available information makes probabilities much clearer.

Much less probable materials have been used to create functional objects - meat was used to make trinket boxes! In Nelson's navy, age old salt beef was carved by sailors into boxes - when polished they looked like they were made of mahogany.