Where does “nigripennis” come from?

nigripennis (Latin) comes from Latin penna, from Proto-Italic petnā, from Proto-Indo-European péth₂r̥, from Proto-Indo-European peth₂- — to spread out; to fly.

nigripennis (Latin): having a black wing or fin, or black feathers

Definitions

having a black wing or fin, or black feathers

Ancestry of “nigripennis”, step by step

nigripennis traces back through two separate lines of ancestry.

via Latin penna

Step	Language	Word	Meaning
1	Latin	penna	wing; feather, especially a flight-feather;...
2	Proto-Italic	petnā	feather; wing
3	Proto-Indo-European	péth₂r̥	wing; feather
4	Proto-Indo-European	peth₂-	to spread out; to fly

via Latin Niger

Step	Language	Word	Meaning
1	Latin	Niger	A Roman agnomen, or "nickname"
2	Proto-Indo-European	negʷ-	bare, naked

Every word from Proto-Indo-European peth₂- →Every word from Proto-Indo-European péth₂r̥ →Every word from Proto-Italic petnā →