Was the leather muscled curiass of the later times sexier?

[Magnus]

Pteryges dont' have a LOT of protective value. In anycase, the only argument for pteryges being made of leather are the smaller, "tongue" pteryges which sit above the longer, textile ones as Jim mentioned. But these could also have been made of metal, or at least metal faced.

See travis clark's webpage on it.

Just because the Romans may or may not have had knowledge of something doesn't mean it was pratical for them to have used it. If they did, there'd be evidence of it. Frescoes depicting armour would be painted brown, etc. This isn't the case.

The question is, can you modify your way of thinking to accept that there is no evidence in any way shape or form for leather armour in the non-lamellar sense?