Reconstruction talk:Proto-Italic/spektlom

Reconstruction
I'm confused about why this reconstruction exists, given that only the Latin is attested. Are there any other Italic words that derive from this, or even IE words from other branches that reflect *spéḱtlom? If not, how do we know this existed in proto-Italic rather than as an innovation in Latin from specio + ulum? 70.175.192.217 05:30, 21 October 2021 (UTC)
 * I added a reference to de Vaan, who says "probably, speculum reflects an instrumental noun *spek-tlo-". He doesn't explicitly give the period for which this etymology is supposed to apply, so this could be a sloppy way of saying it's a post-Proto-Italic derivative from the descendants of *spek- and *-tlo-. There are no cognates outside of Latin that I know of.--Urszag (talk) 16:17, 30 October 2021 (UTC)