Where does “crūrālis” come from?

crūrālis (Latin) comes from Latin -ālis, from Proto-Italic -ālis.

Ancestry of “crūrālis”, step by step

Step	Language	Word	Meaning
1	Latin	-ālis	—
2	Proto-Italic	-ālis	—

crūrālis — Etymology, Origin & Word History | Etymology Explorer