LAUSR

Abstract Accounts in the zoological literature commonly state that the European cave-dwelling “olm,” Proteus anguinus, can reproduce “facultatively” -- switching between oviparity and viviparity according to environmental circumstances. This paper evaluates the widespread allegations of viviparity in this salamander species, tracing their origins to ambiguous reports from more than a century ago. The sole basis for detailed claims for “facultative viviparity” lies with an unreliable (and potentially fraudulent) report that fails to meet minimal scientific standards. The means by which these claims have prevailed and spread reveals the risks of uncritical acceptance of uncorroborated, unreferenced assertions as “common knowledge.” In the absence of trustworthy evidence to the contrary, P. anguinus should be considered as entirely oviparous like its North American confamilials. Given recent demonstration of oviparity in a putatively live-bearing Hydromantes, definitive evidence of viviparity in urodeles is restricted to a single clade of the family Salamandridae.