Stop the presses. There is literally a new record-breaker on the block. Bigger than Argentinosaurus. Possibly bigger than even Puertasaurus, Ruyangosaurus and Alamosaurus. Some of these new giants (yes, there's a whole herd of them found, in VERY good condition) have nearly 10-foot long femurs.
It's a titanosaur to be sure, from Argentina. I suspect based on the femur proportions that this species is a lognkosaur. That sharp lateral bulge very high on the femur gives it away. If anyone wants to illustrate this species, that's the group I'd look at for reference. Quite a challenge!
But rather than steal the thunder I will let the pictures do the talking. Check out my blog for much more detail: http://paleoking.blogspot.com/2014/05/record-smashing-titanosaur-just.html