The Atlantic Forest that hugs the coast of Brazil is home to four small primates found nowhere else on Earth. The most famous of them, the golden lion tamarin, appears on Brazil’s 20-real bill, a part of the day-to-day interactions of people across the country. But not everyone knows the primate’s conservation story, which began in the 1960s and saw it saved from likely extinction through years of challenging work. Its lesser-known but equally charismatic cousins have similar tales of narrowly avoiding extinction, all of which have unfolded in the Atlantic Forest, Brazil’s most devastated and …