HONG KONG — Singapore has discovered more than 14 tons of pangolin scales in what conservation specialists called the largest such seizure of a single shipment worldwide, highlighting the stubbornness of the illegal trade of the scaly anteater.

Roughly 36,000 pangolins were believed to have been killed for the shipment, according to Paul Thomson, an official with the Pangolin Specialist Group, an organization belonging to the International Union for Conservation of Nature. The group called it the biggest seizure of pangolin scales on record.

“The news of this record-shattering seizure is deeply alarming and underscores the fact that pangolins are facing a crisis,” Mr. Thomson said of the…