As Papua New Guinea faced the challenge of introducing a new currency while gaining independence from Australia in 1975, it chose a name with specific cultural and historical meaning: the kina, a shell used as a traditional kind of money into the 20th century. Each kina was divided into 100 toea, named for a smaller shell.

Among more than 800 languages spoken by its people—the most of any country—“kina” is used in two: Tok Pisin, one of three official languages, and Kuanua. Kina are gold-rimmed pearl oyster shells once used widely for trading, as a traditional store of wealth, and for adornment. Toea are shells once used for trading and are valued because they’re found deep in the ocean and only at certain times of the year, according to the central bank’s official history.

The nation of 10 million in the southwestern Pacific marked its first half century of independence in September with commemorative 50 kina banknotes. They feature the founding prime minister, Michael Somare, and the national emblem, the Raggiana bird-of-paradise, which is native to the island’s tropical forests and known for elaborate courtship displays and colorful male plumage. The note shows other examples of the country’s biodiversity: a Queen Alexandra’s birdwing—the world’s largest butterfly, with wings spanning 25–28 centimeters—and a blue orchid, another national symbol. A new 50 toea coin, showing the country’s flag, also marked the anniversary.

“The kina and the toea remain symbols of independence,” Bank of Papua New Guinea Governor Elizabeth Genia said in an August speech announcing the new designs. “The unfinished business of independence is to ensure every kina and every toea earned brings real benefits for our people. Our sovereignty is measured not only by symbols, but by the progress we make as a nation.”

Next year, Papua New Guinea will introduce a new 100 kina note to honor Julius Chan, who shaped early economic policies as the first finance minister and second prime minister. Born on Tanga Island, New Ireland Province, to a Chinese father and Indigenous mother just before World War II, he overcame discrimination to become one of the country’s longest-serving politicians, representing his home province in Parliament until he died in January at age 85.

Chan, knighted by Queen Elizabeth II in 1980 for his service to the former British colony, was known by many Papua New Guineans simply as “Sir J.” The new banknotes bring him full circle, appearing on the currency he helped introduce to a newly independent nation.