Would anyone care to suggest an authoritative absolute date-range for
(a) the loss of sibilance, (b) the complete loss of Goidelic
intervocalic and final /s/? Specifically, how late is it likely that
there was any phonetic sibilance at all in reflexes of the _s_-stem
genitive singular desinence _-esos_?
I realize I am probably asking for the moon, but maybe someone has it
University of Sussex