Where does “selkäpiiluu” come from?

selkäpiiluu (Ingrian) comes from Ingrian selkä, from Proto-Finnic selkä, from Proto-Finno-Permic śelkä.

Ancestry of “selkäpiiluu”, step by step

selkäpiiluu traces back through two separate lines of ancestry.

via Ingrian selkä

StepLanguageWordMeaning
1Ingrianselkäback
2Proto-Finnicselkäback; ridge
3Proto-Finno-Permicśelkä

via Ingrian piiluu

StepLanguageWordMeaning
1Ingrianpiiluuvertebra
2Ingrianluubone
3Proto-Finno-Ugric*luu
Every word from Proto-Finno-Permic śelkäEvery word from Proto-Finnic selkäEvery word from Ingrian selkä