Re: Latin /a/ after labials, IE *mori

I have recently been wondering about Proto-Italic *mari (Latin mare) alongside PIE *mori, and happened across this old thread while trying to figure out the apparent /o/ > /a/ change. However, the thread seems to raise more questions than it answers! :)

So I figure it's worth asking the list's collective wisdom again:
How can this Italic /a/ alongside PIE /o/ as in *mari/*mori be explained? Is it a change of the vowel after a labial as suggested? (I had also wonder if the following /r/ had an effect?) Is the Latin word from a zero grade form? Or ...?

Any ideas? :)

Cheers,
Carl

--- In cybalist@yahoogroups.com, Andrew Jarrette <anjarrette@...> wrote:
> Awhile back we had a bit of a discussion about the idea of Latin <a>
> after labials representing IE *o, the classic example being Latin <mare>
> representing IE *mori (we also talked a bit about Latin /a/ sometimes
> possibly representing IE *e). But if this was a regular change, I have
> found words which seems to be an exception: Latin <moni:le>
> "necklace", from IE *mon- "neck" which is also found in English <mane> and Old English <mene> "necklace"; <moneo:> "remind, admonish"; <mons> "mountain", <mox> "soon, presently". If IE *o regularly became Latin /a/ after
> labials, shouldn't the Latin words be *<mani:le>, *<maneo:>, *<mans>, *<max>?
> [...]
> Did Latin really change any *o after a labial to /a/, or was an IE *a preserved in *mari and other words?

--- In cybalist@yahoogroups.com, Andrew Jarrette <anjarrette@...> wrote:
> One French scholar I read suggests that Latin <mare> is from the zero-grade form, while the Celtic forms are from the o-grade form.