Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Cornish
yr
←
Proto-Brythonic
*ir
(inherited)
←
Proto-Celtic
*ɸūros
(inherited)
←
Welsh
ir
(cognate)
←
Irish
úr
(cognate)
←
Proto-Indo-European
*puHrós
(inherited)
←
Proto-Indo-European
*pewH-
(derived)
→
Welsh
ir
(cognate)