Pangolins, considered the most-trafficked mammals on Earth, are rapidly heading to extinction. Eight extant species of these African and Asian scale-bodied anteaters are commonly recognized, but their evolutionary relationships remain largely unexplored. Here, we present the most comprehensive phylogenetic assessment of pangolins, based on genetic variation of complete mitogenomes and 9 nuclear genes. We confirm deep divergence among Asian and African pangolins occurring not later than the Oligocene-Miocene boundary ca. 23 million years ago (Ma) (95% HPD = 18.7–27.2), limited fossil evidence suggesting dispersals from Europe. We recognize 3 genera including Manis (Asian pangolins), Smutsia (large African pangolins), and Phataginus (small African pangolins), which first diversified in the Middle-Upper Miocene (9.8–13.3 Ma) through a period of gradual cooling coinciding with a worldwide taxonomic diversification among mammals. Based on large mitogenomic distances among the 3 genera (18.3–22.8%) and numerous (18) morphological traits unique to Phataginus, we propose the subfamily Phatagininae subfam. nov. to designate small African pangolins. In contrast with the morphological-based literature, our results establish that the thick-tailed pangolin (Manis crassicaudata) is sister-species of the Sunda (Manis javanica) and Palawan (Manis culionensis) pangolins. Mitogenomic phylogenetic delineations supported additional pangolin species subdivisions (n = 13), including 6 African common pangolin (Phataginus tricuspis) lineages, but these patterns were not fully supported by our multi-locus approach. Finally, we identified more than 5000 informative mitogenomic sites and diagnostic variation from 5 nuclear genes among all species and lineages of pangolins, providing an important resource for further research and for effectively tracing the worldwide pangolin trade.
Eight extant species of pangolins are currently recognized. Recent studies found that two mitochondrial haplotypes identified in confiscations in Hong Kong could not be assigned to any known pangolin species, implying the existence of a species. Here, we report that two additional mitochondrial haplotypes identified in independent confiscations from Yunnan align with the putative species haplotypes supporting the existence of this mysterious species/population. To verify the new species scenario we performed a comprehensive analysis of scale characteristics and 138 whole genomes representing all recognized pangolin species and the cryptic new species, 98 of which were generated here. Our morphometric results clearly attributed this cryptic species to Asian pangolins (Manissp.) and the genomic data provide robust and compelling evidence that it is a pangolin species distinct from those recognized previously, which separated from the Philippine pangolin and Malayan pangolin over 5 Mya. Our study provides a solid genomic basis for its formal recognition as the ninth pangolin species or the fifth Asian one, supporting a new taxonomic classification of pangolins. The effects of glacial climate changes and recent anthropogenic activities driven by illegal trade are inferred to have caused its population decline with the genomic signatures showing low genetic diversity, a high level of inbreeding, and high genetic load. Our finding greatly expands current knowledge of pangolin diversity and evolution and has vital implications for conservation efforts to prevent the extinction of this enigmatic and endangered species from the wild.
The tiger (Panthera tigris) is most recognized for its dark stripes against an orange background. Less well known are three other pelage color variants: white, golden and stripeless snow white (Figure 1A).