Ex ungue leonem

In 1696 the mathematician Johann Bernoulli, writing in the journal
_Philosophical Transactions_, asked for a solution to the 'brachistochrone
problem', What is the path of shortest time between two points A and B
taken by a particle falling from rest under gravity? (The answer is a
cycloid curve.) Six solutions came in, from Bernoulli himself, from Leibniz
... and an anonymous one sent from England. Bernoulli recognised this as
being by Newton, and remarked 'tanquam ex ungue leonem' -- [I can recognise
this] like a lion from its claw. This remark was not original, as it had
already been written by Laevinius Torrentius in 1587. But it sounds like
the end of a hexameter. A search on Perseus doesn't turn up the phrase.
Does anyone know of any older use?

RH