Quoting jrc <jrccea@bellsouth.net>:
In fact, I think the current size limit for flapping flight is below Argentavis, and somewhat above the largest birds living...
I tend to agree with this particular statement, but what do avian limits have to do with pterosaurian (or bat) limits?
Really? You don't think a volant bird the size of _Argentavis_ could exist today (always barring the interference of meddling humans...)?