The butcher grabbed a sack from behind a table piled with bloodied carcasses — copper-coloured duiker, gray-black cane rats, a five-foot crocodile with bulging eyes — at the entrance to the biggest fish market in Lagos state and pulled out a brown ball the size of a grapefruit.

“Pangolin?.?.?. they pay good money,” he said of the Nigerian dealers and Asian buyers offering the equivalent of $30 apiece— more than a third of the local monthly minimum wage — for a critically endangered animal whose scales are prized in some traditional medicines.

The butcher, who did not wish to be named, is a small player in a global trade in pangolins estimated to be worth hundreds of millions of dollars annually. Experts warn that the illicit industry is increasingly centred on Nigeria, which in recent years has grown to become the most important wildlife smuggling hub in Africa.