Marked by dictionaries as only a reconstruction (brosca - broscus) from Romance languages, the origin of Romanian broască (frog) and of Albanian breshkë (turtle) is in fact attested in Late Latin (Papias: rubeta ranae genus bruscus dicit vulgo) — Dan Ungureanu 2024, Istoria limbii române, 233.
Papias text here.
Ungureanu also suggests the possibility of a connection between Lombard brosco, Romansh rušk, ruašć, Veronese roschi, and Italian rospo. See also Elisa De Roberto, Glossari, versioni e proverbi:
>Maggiori ragguagli otteniamo ricorrendo al vocabolario di Papias, che sotto rubeta inserisce oltre alla definizione di «ranae genus», anche la dicitura «bruscus dicit vulgo»: dal lat. volg. bruscus/*broscus ‘rospo’ si sarebbe sviluppato il lat. medievale roscus, che avrebbe dato poi nei volgari italiani rospo (ma in milanese antico si ha ancora brosco, usato da Bonvesin).
>More information we get by resorting to the vocabulary of Papias, which under rubeta inserts, in addition to the definition of «ranae genus», mentions also the words «bruscus dicit vulgo»: from the lat. volg. bruscus/*broscus ‘rospo’ would have developed the medieval lat. roscus, which would then give in the vulgar Italian dialects rospo = toad (but in ancient Milanese we still have brosco, used by Bonvesin).