Around 3.4 million years ago, a hidden evolutionary tale unfolded in the Indo-Burma region: a cryptic pangolin species diverged from the Chinese pangolin (Manis pentadactyla).  Long thought to be the same species, Indian scientists now propose it as distinct, though some experts remain skeptical.

In a recent study published in Mammalian Biology, scientists from the Zoological Survey of India (ZSI) scientists described the Indo-Burmese pangolin as a new species, Manis indoburmanica, after mitochondrial DNA (mtDNA) analysis of pangolin seizures from the westernmost range of the Chinese pangolin showed a considerable genetic distinction.

“Genomic analyses reveal that it diverged from the Chinese pangolin around 3.4 million years ago, indicating a long independent evolutionary history,” study co-author Mukesh Thakur, a senior scientist at the ZSI, told Mongabay by email. There was enough genetic difference uncovered in the analysis between Manis indoburmanica and Manis pentadactyla to suggest species-level differentiation, he added. 

If the Indo-Burmese pangolin is officially accepted by the science and conservation communities, it would bring the total number of known pangolin species to nine. This includes four other Asian species — Chinese, Indian (M. crassicaudata), Sunda (M. javanica) and Philippine (M. culionensis) — and four African: black-bellied (Phataginus tetradactyla), white-bellied (Phataginus tricuspis), Temminck’s (Smutsia temminckii) and the giant ground pangolin (Smutsia gigantea).

Historical misidentifications?

Thakur said the late identification of M. indoburmanica is primarily due to limited genetic studies. “Historically, pangolin taxonomy has relied heavily on morphology” — physical characteristics — “which can be misleading due to similar physical traits among species. The advent of genomic tools and high-throughput sequencing allowed us to uncover this cryptic diversity,” he said.

He added the Indo-Burmese pangolin’s range overlaps with those of the Chinese and Indian pangolins, leading to historical misidentifications. “Until now, populations in northeastern India and surrounding regions were often assumed to belong to either of these two species,” Thakur added.

Pangolins’ elusive, nocturnal and solitary nature, along with low population densities, has made studying them in the wild difficult, further complicating species identification, he said.

Thakur said the Indo-Burmese pangolin shares several traits with other Asian pangolins, especially its closest relatives, the Chinese and Indian pangolins. These include bristle-like hair between its scales. Despite these similarities, “preliminary observations suggest variations in scale structure, body size, and cranial features compared to its Asian counterparts,” Thakur said.

‘A few pieces of evidence still missing’

Sean Heighton, taxonomy co-chair of the Pangolin Specialist Group at the IUCN, the global wildlife conservation authority, called the proposed Indo-Burmese pangolin description an “exciting find with major implications for pangolin taxonomy and conservation.” He said the ZSI team’s analyses were “robust and widespread from a molecular DNA perspective.”

Heighton agreed that the proposed Indo-Burmese pangolin fits with the paper’s description of  it as a new “phylogenetic species,” meaning there’s sufficient genetic disparity to distinguish it from the Chinese pangolin, even if physically there’s not much difference.

However, he noted that “a few pieces of evidence are still missing for us to confidently validate this new species,” specifically calling for additional comparative morphological evidence between M. indoburmanica and M. pentadactyla, as well as a review of primary taxonomic literature to collate all available names and descriptions of similar species.

Matthew Shirley, overall co-chair of the Pangolin Specialist Group, said they agree that “cryptic species are valid species,” but stressed that “morphology is critical for our practical ability to implement management programs.” 

“If people do not know what they have in hand, it is hard to make decisions, ” he told Mongabay. Thus, “the PSG does not yet recognize Manis indoburmica or Manis mysteria as fully validated ninth and/or tenth pangolin species.”

The Asian mysterious pangolin, M. mysteria, is thought by some scientists to have diverged from the Philippine and Sunda pangolins around 5.05 million years ago and was described as another cryptic species  in 2023.

Shirley said that taxonomy, like all scientific disciplines, demands rigorous validation before its findings can gain full acceptance within the scientific and conservation communities — especially for species as heavily impacted by international trade as pangolins. In this case, he said, incorporating nuclear data alongside morphological data will “substantially add to the power of these results,” which he added he hoped to see in the ZSI team’s follow-up publications.

Thakur said his team fully agrees with the PSG’s feedback and is actively working on collecting additional specimens for a more comprehensive morphological assessment. 

Given how little the Asian pangolins differ physically, he said, “distinguishing species based solely on external features can be challenging, which is why we prioritized molecular data in our initial description. However, we are actively working on detailed morphometric analyses, particularly focusing on cranial and scale characteristics, to complement our findings.”

Their initial assessment showed the Indo-Burmese pangolin differs from its Asian relatives in several ways. Its scales range from dark brown to olive-brown with a pinkish face, compared to the yellow-brown coloration of the Chinese pangolin and the coarser, yellowish-brown hue of the Indian pangolin. In size, it’s slightly smaller than the Indian pangolin but comparable to the Chinese pangolin. Its scales also show slight variations from other Asian pangolins, and its snout-to-ear length serves as a key distinguishing feature, according to the ZSI team.

For nuclear DNA evidence, Thakur said they’re already carrying out even more detailed DNA analysis that will “offer deeper insights into gene flow, and genomic distinctiveness between M. indoburmanica and other Asian pangolins.” The team is also conducting an in-depth literature review to collate all previously described names and morphological data to “ensure that M. indoburmanica is appropriately classified and distinct from any historically named taxa.”

Geoclimatic events driving distribution

Indo-Burmese pangolin appears to be adapted to the unique environmental conditions of the Indo-Burma region, a biodiversity hotspot characterized by complex mountainous and subtropical habitats, Thakur said.

It’s found in the westernmost range of the Chinese pangolin, an area straddling eastern Nepal, northeastern India and northwestern Myanmar, the study says. In India, it occurs in parts of Arunachal Pradesh, Assam and other northeastern states. The species lives at elevations of 180-1,830 meters (590-6,000 feet).

Heighton said this study sheds light on the complex, still unclear evolutionary history of pangolins, noting that our current understanding of the Chinese pangolin’s evolution has been limited to the southeastern part of its distribution.

“This research focuses on a geographical area (westernmost part) that until now has been overlooked, yet it is an area well-known for the speciation of mammalian groups due to the influence of the Tibetan plateau,” he added.

Illegal trafficking as a primary threat

Like all pangolins, the Indo-Burmese pangolin faces severe threats, primarily from the illegal wildlife trade, the ZSI researchers said. “The Indo-Burmese pangolin is particularly vulnerable as its habitat falls within major trafficking routes in South and Southeast Asia,” Thakur noted.

James Toone, pangolin campaign leader at the U.K.-based Environmental Investigation Agency, expressed optimism about the description of the Indo-Burmese pangolin but voiced concern that illegal trade pressures on all pangolins have already put this species at risk of extinction — and that its identification as a separate species could pose a threat in itself.

That’s because while the eight other known pangolin species are individually listed in Appendix I of CITES, the international wildlife trade convention — meaning their commercial trade is prohibited — the pangolin genus as a whole is only listed in Appendix II, where some trade is permitted.

“This means that commercial trade in these new species could be allowed and this would be a real concern,” Toone said in a news release.

PSG’s Shirley confirmed that there are “no blanket protections” for pangolins when it comes to potentially newly recognized taxa. “When new species like this are proposed, we all have to be very diligent that they do not become inadvertent loopholes for trafficking, for example,” Shirley said.

Given its limited distribution, high levels of poaching, and habitat loss resulting from agriculture expansion, infrastructure development and the climate crisis, the Indo-Burmese pangolin would likely qualify for an endangered or critically endangered status under the criteria of the IUCN Red List.

“The assessment would depend on further ecological and population studies, but the species is undoubtedly under severe threat,” Thakur said.

Banner image: The proposed Indo-Burmese pangolin has dark brown and olive-brown scales, with a pinkish face, a new study says. Image courtesy of Zoological Survey of India

Citations:

Wangmo, L. K., Ghosh, A., Dolker, S., Joshi, B. D., Sharma, L. K., & Thakur, M. (2025). Indo-Burmese pangolin (Manis indoburmanica): A novel phylogenetic species of pangolin evolved in Asia. Mammalian Biology. doi:10.1007/s42991-024-00475-7

Gu, T., Wu, H., Yang, F., Gaubert, P., Heighton, S. P., Fu, Y., … Yu, L. (2023). Genomic analysis reveals a cryptic pangolin species. Proceedings of the National Academy of Sciences, 120(40). doi:10.1073/pnas.2304096120

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