Metathesis in sonant+ labiovelars, Greek

Let me pick three words as example: nyx, onyx, lykos

 

IE *n.kWt- > *nukt- > Greek nyx (nykt-) "night"

IE *H3o-n.gWH- > *o-nugH- > Greek onyx (onykh-) "nail"

IE *wl.kWos > *wluko- > Greek lykos "wolf"

 

Perhaps more two words can be added to this list: nymphe: and gymnos.

 

My question is:

These shifts represent a regular trend in IE>Greek (sonant+labiovelar > sonant+u+velar) or may be loans from another IE language (but very close to Greek)

 

 

Joao SL