Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Catalan
eruga
←
Proto-Indo-European
*ǵʰer(s)-uk-eh₂
(inherited)
←
Proto-Indo-European
*ǵʰers-
(derived)
←
Latin
ērūca
(inherited)
←
Old Occitan
eruga
(inherited)
←
Old Occitan
eruca
(mention)
→
Catalan
arna
(link)
→
Catalan
ruca
(doublet)