There is an important omission in that Guardian article. They cite a Latin professor said to have helped decipher the artifact and then another scholar of Indo-European linguistics:
"Velaza’s colleague Joaquín Gorrochategui, a professor of Indo-European linguistics at the University of the Basque country, said the hand’s secrets would change the way scholars looked at the Vascones.'This piece upends how we’d thought about the Vascones and writing until now ... We were almost convinced that the ancient Vascones were illiterate and didn’t use writing except when it came to minting coins."
What they fail to tell their readers is that Basque is not an Indo-European language at all. It's a language isolate – while Latin, Welsh, German, Danish, Greek, Armenian, Persian, Hindi, Urdu etc. are all related to each other, Basque is the only remnant of the languages that were spoken in Western Europe before the Indo-Europeans took over.
"Velaza’s colleague Joaquín Gorrochategui, a professor of Indo-European linguistics at the University of the Basque country, said the hand’s secrets would change the way scholars looked at the Vascones.'This piece upends how we’d thought about the Vascones and writing until now ... We were almost convinced that the ancient Vascones were illiterate and didn’t use writing except when it came to minting coins."
What they fail to tell their readers is that Basque is not an Indo-European language at all. It's a language isolate – while Latin, Welsh, German, Danish, Greek, Armenian, Persian, Hindi, Urdu etc. are all related to each other, Basque is the only remnant of the languages that were spoken in Western Europe before the Indo-Europeans took over.