Mitogenomic phylogeny of the Asian colobine genus Trachypithecus with special focus on Trachypithecus phayrei(Blyth, 1847) and description of a new species

Trachypithecus,which currently contains 20 species divided into four groups,is the most speciose and geographically dispersed genus among Asian colobines.Despite several morphological and molecular studies,however,its evolutionary history and phylogeography remain poorly understood.Phayre’s langur(Trachypithecus phayrei) is one of the most widespread members of the genus,but details on its actual distribution and intraspecific taxonomy are limited and controversial.Thus,to elucidate the evolutionary history of Trachypithecus and to clarify the intraspecific taxonomy and distribution of T.phayrei,we sequenced 41 mitochondrial genomes from georeferenced fecal samples and museum specimens,including two holotypes.Phylogenetic analyses revealed a robustly supported phylogeny of Trachypithecus,suggesting that the T.pileatus group branched first,followed by the T.francoisi group,and the T.cristatus and T.obscurus groups most recently.The four species groups diverged from each other 4.5-3.1 million years ago(Ma),while speciation events within these groups occurred much more recently(1.6-0.3 Ma).Within T.phayrei,we found three clades that diverged 1.0-0.9 Ma,indicating the existence of three rather than two taxa.Following the phylogenetic species concept and based on genetic,morphological,and ecological differences,we elevate the T.phayrei subspecies to species level,describe a new species from central Myanmar,and refine the distribution of the three taxa.Overall,our study highlights the importance of museum specimens and provides new insights not only into the evolutionary history of T.phayrei but the entire Trachypithecus genus as well.

Mitogenomes of historical type specimens unravel the taxonomy of sportive lemurs(Lepilemur spp.)in Northwest Madagascar

Accurate information on name-bearing types,including corresponding type localities,is essential for proper taxonomy.However,such geographic information is often missing or unreliable.The localities of type specimens collected 100–200 years ago can be difficult to trace due to changes in local names or simple inaccuracies.Such a case can be found for the gray-backed sportive lemur(Lepilemur dorsalis),with its type locality imprecisely fixed as Northwest Madagascar.In recent years,eight species have been newly described for the Inter-River-Systems(IRSs)of this region,however the designation of L.dorsalis remains controversial due to a lack of a precise type locality.Here,we sequenced the complete mitochondrial genomes(mitogenomes)of type specimens of L.dorsalis and L.grandidieri,which is currently recognized as a synonym of L.dorsalis and compared their sequences with those of samples of known provenance from different IRSs.Results showed that the two type specimens of L.dorsalis and L.grandidieri had identical mitogenome sequences and clustered closely with samples collected in IRS V,indicating that the type locality could be fixed to IRS V.Consequently,L.dorsalis occurs in IRS V,and L.grandidieri and L.mittermeieri are junior synonyms of L.dorsalis.This finding demonstrates the value of type specimens for clarifying phylogeographic and taxonomic questions and clarifies the taxonomy of sportive lemurs in Northwest Madagascar.