Researchers Discover New Lineage of Critically Endangered Sunda Pangolins Using Scales in the Museum’s Collection | Smithsonian Voices

For world pangolin day, learn more about how genetic researchers helped pinpoint a hidden lineage of the critically endangered mammals

Each year, scientists describe between 15,000 and 18,000 animal species. Some of these are species entirely new to science while others are previously identified animals in need of a taxonomic correction. For example, in 2024 researchers examining squirrel specimens in the National Museum of Natural History’s collection discovered that two previously described subspecies actually represented fully unique squirrel species.

This research team, which included zoologist Arlo Hinckley, recently made another discovery in the museum’s collection: a new lineage of the scale-covered Sunda pangolin (Manis javanica) that live on a group of islands in Indonesia. Their findings, published last September in the journal Biology Letters, could help researchers pinpoint the origins of pangolin remains, which are illegally trafficked around the world.

“This lineage represents a new evolutionarily significant unit of Sunda pangolins which has consequences for conserving the species,” said Hinckley, who received an award for the recent paper and is currently a postdoctoral researcher at Spain’s Universidad de Sevilla in addition to a research associate at the museum. “These findings offer key insights for tracing the origins of trafficked pangolins and understanding their historical dispersal.”

Pangolins (pronounced ‘pang-guh-luhn’) are insect-eating mammals covered in plate-like scales made of keratin (the same material as fingernails) that create an armor-like suit. These scales defend the mammal from insect bites as it slurps up ants and termites with its long tongue.

While it has similar tastes to anteaters and the amor-clad appearance of an armadillo, pangolins are not closely related to either of these animals. In fact, pangolins are grouped within their own taxonomic order. Today there are eight living species of pangolins found across sub-Saharan Africa and southern Asia.

For decades, pangolins have been threatened by habitat loss and poaching. These mammals are the most trafficked animal in the world — the International Union for Conservation of Nature (IUCN) Red List estimates wild pangolins are captured every five minutes.

Hinckley and his colleagues are aiming to combat illegal wildlife trade by tracking the origins of unethically traded species. The team works with several Indigenous groups that live in mountainous regions of northern Borneo. For centuries, these communities consumed pangolin meat, an important source of protein in these rural environments.

The main concern is organized poacher trafficking. A poacher’s primary target is pangolin scales, which can fetch a high price in places like Vietnam and China. In some places, one kilogram (2.2 pounds) of scales can sell for over $3,500. The scales are used in traditional medicines in several cultures due to proposed aphrodisiac qualities. Last October, border guards in Vietnam confiscated seven metric tons of rare wildlife parts ranging from python skins to bird beaks. The majority of the haul was some 4.2 tons of pangolin scales. “The number of scales came from hundreds of pangolins,” Hinckley said. “It’s clear these animals are going to go extinct in the next few decades if things don’t change.”

During his stint as a postdoctoral researcher at the Smithsonian, Hinckley came across the description of a unique genetic lineage of pangolins. Researchers in China had made the discovery by analyzing pangolin scales confiscated in Hong Kong. As they compared the genetic data from the scales with DNA from the eight known pangolin species, the team realized that the confiscated samples represented an entirely new species of pangolin that was being poached before scientists could even describe it.

To formally name the new animal, scientists needed a holotype specimen, which serves as the physical reference for a species. In the case of the unknown pangolin, researchers had only isolated scales to work with, which limited their knowledge of the whole animal like a puzzle that’s missing several pieces.

Because the scales were collected illegally, the researchers were also missing information for where the new pangolin lives in the wild. Essentially, there was no home address, which made it virtually impossible for local governments to protect the mysterious animal from poaching.

Hinckley and his colleagues, which included museum technician Mary Faith Flores and Melissa Hawkins, the museum’s curator of mammals, took on the challenge to describe the new pangolin in detail and pinpoint its whereabouts. The museum’s collection holds more than 40 pangolin specimens from Asia, some of which have already had their genetic code sequenced. Importantly, these specimens all have corresponding location data, which allowed Hinckley to focus on pangolin specimens from localities that had not been sampled in depth. This led the team to examine Sunda pangolin specimens collected from areas including Cambodia, Laos and several Indonesian islands.

The team took samples of claws, scales, osteocrusts (pieces of brain or muscle retained inside the skull), bone fragments and liver and extracted traces of DNA inside. Some of the genetic sequences were damaged, but Flores utilized a new method to obtain data from one single strand of DNA instead of two. According to Hinckley, this allowed them to carefully rescue data from even the most damaged DNA fragments. They used the recovered genetic data to construct a divergence time tree, which allowed them to pinpoint when certain groups of related pangolins split off from one another to become distinct lineages.

The work revealed that a lineage of Sunda pangolins that live on Indonesia’s Mentawai Islands split off from a group of Sunda pangolins living on mainland Southeast Asia around 760,000 years ago. Because these pangolin populations are genetically distinct, the team proposes that the lineage on the Mentawai Islands represent an “evolutionary significant unit,” or a genetically distinct population within a species. Hinckley notes that genetic traits that differ between various pangolin populations could make some lineages more resistant to environmental conditions like increased temperature or reduced rainfall than other populations that are adapted for cooler, drier climates.

Due to the small distribution of the Mentawai pangolin lineage, conservation will be crucial for maintaining this pocket of genetic diversity. According to Hinckley, maintaining any pangolin population is crucial for the survival of the whole species. “Imagine a species is just like a tree with different branches that represent different genetic lineages,” he said. “Different branches might have different traits that could make the species more resistant to different challenges in the future.”

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