I've read about the archaic Roman practice of killing 60-year-olds by pushing them off a bridge, in a book by historian Eva Cantarella, namely Perfino Catone scriveva ricette - I greci, i romani e noi ("Even Cato wrote recipes - The Greeks, the Romans and us"). It wasn't translated in English however.
The proverb sexagenarios de ponte deici oportet (it is necessary to push 60-year-olds off the bridge) seems to confirm the existence of the ritual. However, after some research, I've found sources claiming that the debate on the existence of this ritual hasn't ended yet. Interestingly, already during the Late Republic, it seems the Romans weren't sure about the origin of the proverb, and some authors tried (unsuccessfully) to prove the ritual never existed.
Is there a general consensus today? If so, when is it believed that the Romans started replacing the then-elders with the Argei, a kind of dummies?