I am a Cardoso and based on some research it is a name ot Portuguese origin, it traveled the world but most popular in portuguese speaking countries, mostly traced to north of portugal, the portuguese migrated the world for hundreds of years, if you notice most of the messages are from places were the portuguese have been , (India, South America, Indies, Cabo Verde} this is all places that the portuguese at some time in history have lived, there is no dought in my mind of its origin.
Paulino Cardoso, made in portugal , live in the USA