Primate Taxonomy Research Articles

Taxonomy and systematics of the Neotropical primates: a review and update

The database of the IUCN SSC Primate Specialist Group currently (December 2023) registers 218 species and subspecies of Neotropical primates in 24 genera and five families. In the early 1960s, the diversity of Neotropical primates was estimated to be around 200 species and subspecies. From then, through the 1970s to the mid-1990s, however, the perception of the region’s primate diversity dropped, and reached an all-time low at 83 species and subspecies in 1980 (A World List of Mammalian Species, G. B. Corbet and J. E. Hill, British Museum (Natural History), Comstock Publishing, Cornell University Press, London and Ithaca). Interest in taxonomy and primate field research in the Neotropics was subdued up to the late 1970s. Change was sparked by the burgeoning capture of primates for biomedical research in the 1950s and 1960s, and the increasing destruction of the Amazon rainforests from the late 1970s. The numbers increased, at first slowly, but then, in 1995, they leapt back to the 200s in anticipation of a book by C. P. Groves (2001, Primate Taxonomy, Smithsonian Institution Press, Washington, DC). The species’ counts (not including subspecies) rose due to the adoption of the Phylogenetic Species Concept over the Biological Species Concept, the former favoring the category of species over subspecies. In this article, we discuss the changes in species and subspecies numbers in the classification of the Neotropical primates, and report on the taxonomic changes resulting from taxonomic research ongoing since 2012. We emphasize the importance of taxonomic research for an understanding of the diversity of primates, and for conservation planning, not least in identifying the populations that are threatened.

Apes Unlike Us: Human-Ingroup Protection Against Encroaching Simianity in UK Newspapers

Abstract We often pigeonhole our surroundings into dualistic categories. This capacity to function as reductionists may help us problem-solve when pressed in terms of survival or reproduction. Alternatively, binary categories may be reflective of certain socioecological conditions, and thus social constructs. This study explores classifications of nonhuman primate taxonomy via the coding of human–primate boundary categorizations during 16 years of UK newspaper reporting (1995–2010) to explore whether societal concepts of simianity reflect sociopolitical events – in other words, cultural influence resulting in ingroup boundary enforcement, with less inclusionality under more turbulent scenarios. The results indicate that societal shakiness accounts for the minimization of “human” ingroups at the expense of other primates. Human–primate infrahumanization possibly reflects a cognitive adaptation towards outgroup-directed dichotomous thinking in stress states. That said, the fluidity of the results in the context of societal change also suggests cultural influence on categorical dichotomous sets often accepted as “natural.”

Predictors of taxonomic splitting and its role in primate conservation

AbstractSpecies are the main unit used to measure biodiversity, but different preferred operational criteria can lead to very different delineations. For instance, named primate species have more than doubled in number since 1982. Such increases have been partly attributed to a shift away from the “biological species concept” (BSC) in favor of less inclusive species criteria. Critics of recent changes in primate taxonomy have suggested taxonomic splitting may be biased toward certain clades and have unfavorable consequences for conservation. Here, we explore predictors of taxonomic splitting across primate taxa since the initial shift away from the BSC nearly 40 years ago. We do not find evidence that net diversification rate, the rate of lineage formation over evolutionary time, is significantly linked to splitting, contrary to expectations if new species concepts and taxonomic methods identify incipient species. We also do not find evidence that research effort in fields where work has been suggested to motivate splitting is associated with increases in species numbers among genera. To test the suggestion that splitting groups is likely to increase their perceived risk of extinction, we test whether genera that have undergone more splitting have also observed a greater increase in their proportion of threatened species since the initial shift away from older taxonomic methods. We find no cohesive signal of taxonomic splitting leading to higher threat probabilities across primate genera. Thus, our analysis suggests that the threat statuses of primate species are not being overwhelmingly driven by splitting. Regardless, we echo warnings that it is unwise for conservation to be reliant on taxonomic stability. Species (however defined) are not independent from one another, thus, monitoring and managing them as such may not meet the overarching goal of conserving biodiversity.

On the problem of craniological differentiation in two species of the green monkeys: Chlorocebus pygerythrus and C. aethiops (Cercopithecidae, Primates)

The problem of taxonomic differentiation in the order Primates is one of the important problems of evolutionary anthropology and primatology. The systematics of primates reflects their evolutionary relationships and allows to reconstruct the possible ways of formation of particular groups. Clarification of primate taxonomy involves a wide range of data, primarily from the field of morphology. Among the morphological features that distinguish particular taxa, the special role belongs to the system of craniological characters, which allow diagnosing the skulls in museum collections or fossil materials. The article is devoted to craniological identification of two species of the genus Chlorocebus: Chlorocebus pygerythrus (vervets) and Chlorocebus aethiops (grivets).

The relative efficacy of the cranium and os coxa for taxonomic assessment in macaques.

The cranium is generally considered more reliable than the postcranium for assessing primate taxonomy, although recent research suggests that pelvic shape may be equally reliable. However, little research has focused on intrageneric taxonomic discrimination. Here, we test the relative taxonomic efficacy of the cranium and os coxa for differentiating two macaque species, with and without considering sexual dimorphism. Geometric morphometric analyses were performed on cranial and os coxa landmarks for 119 adult Macaca fascicularis, M. mulatta, and Chlorocebus pygerythrus. Among-group shape variation was examined using canonical variates analyses. Cross-validated discriminant function analysis provided rates of correct group classification. Additionally, average morphological distances were compared with neutral genetic distances. Macaque species were clearly differentiated, both cranially and pelvically, when sex was not considered. Males were more often correctly classified based on the os coxa, while female classification rates were high for both morphologies. Female crania and male os coxa were differentiated approximately the same as genetic distance, while male crania were more similar (convergent), and female os coxa were more divergent than expected based on genetic distance. The hypothesis that cranial and os coxal shape can be used to discriminate among macaque species was supported. The cranium was better at differentiating females, while the os coxa was better at differentiating male macaques. Hence, there is no a priori reason for preferring the cranium when assessing intragenetic taxonomic relationships, but the effects of high levels of sexual dimorphism must be corrected for to accurately assess taxonomic signatures.

Effect of river size on Amazonian primate community structure: A biogeographic analysis using updated taxonomic assessments.

The mechanisms that underlie the diversification of Neotropical primates remain contested. One mechanism that has found support is the riverine barrier hypothesis (RBH), which postulates that large rivers impede gene flow between populations on opposite riverbanks and promote allopatric speciation. Ayres and Clutton-Brock (1992) demonstrated that larger Amazonian rivers acted as barriers, delineating the distribution limits of primate species. However, profound changes in taxonomy and species concepts have led to the proliferation of Neotropical primate taxa, which may have reduced support for their results. Using the most recent taxonomic assessments and distribution maps, we tested the effect of increasing river size on the similarity of opposite riverbank primate communities in the Amazon. First, we conducted a literature review of primate taxonomy and developed a comprehensive spatial database, then applied geographical information system to query mapped primate ranges against the riverine geography of the Amazon watershed to produce a similarity index for opposite riverbank communities. Finally, we ran models to test how measures of river size predicted levels of similarity. We found that, almost without exception, similarity scores were lower than scores from Ayres and Clutton-Brock (1992) for the same rivers. Our model showed a significant negative relationship between streamflow and similarity in all tests, and found river width significant for the segmented Amazon, but not for multiple Amazon watershed rivers. Our results support the RBH insofar as they provide evidence for the prediction that rivers with higher streamflow act as more substantial barriers to dispersal, and accordingly exhibit greater variation in community composition between riverbanks.

Phylogeography of the Mantled Howler Monkey (Alouatta palliata; Atelidae, Primates) across Its Geographical Range by Means of Mitochondrial Genetic Analyses and New Insights about the Phylogeny of Alouatta

We analyzed 156 specimens of diverse howler monkey taxa (Alouatta; Atelidae, Primates) for different mitochondrial genes (5,567 base pairs), with special emphasis on A. palliata and related taxa. Our results showed no relevant differences among individuals of different putative taxa, A. p. palliata, A. p. aequatorialis, A. coibensis coibensis, and A. c. trabeata. We found no spatial differences in genetic structure of A. p. palliata throughout Costa Rica, Nicaragua, and Honduras. A. p. mexicana (genetic distance: 1.6-2.1%) was the most differentiated taxon within A. palliata. Therefore, we postulate the existence of only 2 clearly defined subspecies within A. palliata (A. p. palliata and A. p. mexicana). A. palliata and A. pigra (traditionally considered a subspecies of A. palliata) are 2 clearly differentiated species as was demonstrated by Cortés-Ortiz and colleagues in 2003, with a temporal split between the 2 species around 3.6-3.7 million years ago (MYA). Our results with the Median Joining Network procedure showed that the ancestors of the cis-Andean Alouatta gave rise to the ancestors of the trans-Andean Alouatta around 6.0-6.9 MYA. As Cortés-Ortiz et al. showed, A. sara and A. macconnelli are differentiable species from A. seniculus, although the first 2 taxa were traditionally considered subspecies of A. seniculus. Our findings agree with the possibility that the ancestor of A. sara gave rise to the ancestor of A. pigra in northern South America. In turn, the ancestor of A. pigra originated the ancestor of A. palliata. Two of our results strongly support the hypothesis that the South American A. palliata (the putative A. p. aequatorialis) was the original population of this species; it has high genetic diversity and no evidence of population expansion. The Central America A. palliata is the derived population. It has low genetic diversity and there is clear evidence of population expansion. However, A. palliata and A. pigra probably migrated into Central America by 2 different routes: the Isthmus of Panama (A. palliata) and Caribbean island arch (A. pigra). Finally, the red howler monkeys from the island of Trinidad in the Caribbean Sea were not A. macconnelli (= A. s. stramineus) as Groves maintained in his influential 2001 publication on primate taxonomy. This taxon is more related to A. s. seniculus, although it formed a monophyletic clade. Future molecular and karyotypic studies will show if the Trinidad red howler monkeys should be considered as an extension of the Venezuelan taxon, A. arctoidea, as a subspecies of A. seniculus(A. s. seniculus), or, in the case of extensive chromosomal rearrangements, even a new species.

Primate Taxonomy: Inflation or Real?

This article reviews changes in primate taxonomy, especially those pertaining to the meaning of the term species, since its inception two and a half centuries ago. Despite continuing discoveries and the involvement of competent practitioners, the adoption of the polytypic species concept, especially underpinned by the biological species concept, ensured that primate taxonomy was in a sorry state by the middle of the twentieth century. In the latter half of the twentieth century, a gradual rethinking of the nature of species took place, and many different species concepts were proposed. The phylogenetic species concept has been widely adopted over the past ∼20 years, sustained by a gradual realization that species are evolutionary lineages. This review provides examples of how the old way of thinking about species hampered our understanding of primate biodiversity and of how the phylogenetic species concept (or the diagnosability criterion under the general lineage concept) has clarified matters, opening them up for discussion. The adoption of this evolutionary view of species has implications for conservation, particularly because it increases recognition of biodiversity.

Intra- and interspecific variation in macaque molar enamel thickness.

Enamel thickness has played an important role in studies of primate taxonomy, phylogeny, and functional morphology, although its variation among hominins is poorly understood. Macaques parallel hominins in their widespread geographic distribution, relative range of body sizes, and radiation during the last five million years. To explore enamel thickness variation, we quantified average and relative enamel thickness (AET and RET) in Macaca arctoides, Macaca fascicularis, Macaca fuscata, Macaca mulatta, Macaca nemestrina, and Macaca sylvanus. Enamel area, dentine area, and enamel-dentine junction length were measured from mesial sections of 386 molars scanned with micro-computed tomography, yielding AET and RET indices. Intraspecific sex differences were not found in AET or RET. Macaca fuscata had the highest AET and RET, M. fascicularis showed the lowest AET, and M. arctoides had the lowest RET. The latitudinal distribution of macaque species was associated with AET for these six species. Temperate macaques had thicker molar enamel than did tropical macaques, suggesting that thick enamel may be adaptive in seasonal environments. Additional research is needed to determine if thick enamel in temperate macaques is a response to intensified hard-object feeding, increased abrasion, and/or a broader diet with a greater range of food material properties. The extreme ecological flexibility of macaques may prohibit identification of consistent trends between specific diets and enamel thickness conditions. Such complications of interpretation of ecological variability, dietary diversity, and enamel thickness may similarly apply for fossil Homo species.

An investigation of ecological correlates with hand and foot morphology in callitrichid primates

Studies of primate taxonomy and phylogeny often depend on comparisons of limb dimensions, yet there is little information on how morphology correlates and contributes to foraging strategies and ecology. Callitrichid primates are ideal for comparative studies as they exhibit a range of body size, limb proportions and diet. Many callitrichid species exhibit a high degree of exudativory, and to efficiently exploit these resources, they are assumed to have evolved morphologies that reflect a level of dependence on these resources. We tested assumptions by considering measurements of limb proportion and frictional features of the volar surfaces in preserved specimens of 25 species with relation to published life history and ecological data. The degree of exudativory and utilization of vertical substrates during foraging were found to correlate both with size and with size-corrected foot and hand dimensions. Smaller species, which engage in greater degrees of exudativory, had proportionally longer hands and feet and more curved claw-like tegulae (nails) on their digits to facilitate climbing on vertical substrates. The density of patterned ridges (dermatoglyphs) on the volar surfaces of the hands and feet is higher in more exudativorous genera, suggesting a role in climbing on vertical tree trunks during foraging. Dermatoglyph comparisons suggest that ridges on the soles and palms may facilitate food procurement by enhancing frictional grip during exudate feeding. Volar pad features corroborate taxonomic relationships described from dental morphology.

The Origins of Anthropological Genetics

Although we often date the conflict of “molecules and morphology” in biological anthropology to the 1962 Wenner-Gren conference “Classification and Human Evolution,” the roots of the conflict extend considerably deeper. In the first half of the twentieth century, two established research traditions applied genetic data to problems in physical anthropology: racial serology and systematic serology. These had a tense relationship with the more mainstream areas of racial anthropology and primate taxonomy. Both produced conclusions that were often difficult to reconcile with traditional physical anthropology but that laid claim to the authoritative voices of genetics and evolution. They were also less relevant and less threatening to general anthropology than the other movement for the application of genetics to anthropological problems—eugenics—had been. I discuss the relations of genetics to anthropology as manifested in the areas of eugenics, race, and primate taxonomy in the early twentieth century and the...

Taxonomy and conservation of Vietnam's primates: a review

Vietnam has the highest number of primate taxa overall (24-27) and the highest number of globally threatened primate taxa (minimum 20) in Mainland Southeast Asia. Conservation management of these species depends in part on resolving taxonomic uncertainties, which remain numerous among the Asian primates. Recent research on genetic, morphological, and acoustic diversity in Vietnam's primates has clarified some of these uncertainties, although a number of significant classification issues still remain. Herein, we summarize and compare the major current taxonomic classifications of Vietnam's primates, discuss recent advances in the context of these taxonomies, and suggest key areas for additional research to best inform conservation efforts in a region crucial to global primate diversity. Among the most important next steps for the conservation of Vietnam's primates is a new consensus list of Asian primates that resolves current differences between major taxonomies, incorporates recent research advances, and recognizes units of diversity at scales below the species-level, whether termed populations, morphs, or subspecies. Priority should be placed on recognizing distinct populations, regardless of the species concept in use, in order to foster the evolutionary processes necessary for primate populations to cope with inevitable environmental changes. The long-term conservation of Vietnam's primates depends not only on an accepted and accurate taxonomy but also on funding for on-the-ground conservation activities, including training, and the continued dedication and leadership of Vietnamese researchers and managers.

A Molecular Phylogeny of Living Primates

Comparative genomic analyses of primates offer considerable potential to define and understand the processes that mold, shape, and transform the human genome. However, primate taxonomy is both complex and controversial, with marginal unifying consensus of the evolutionary hierarchy of extant primate species. Here we provide new genomic sequence (∼8 Mb) from 186 primates representing 61 (∼90%) of the described genera, and we include outgroup species from Dermoptera, Scandentia, and Lagomorpha. The resultant phylogeny is exceptionally robust and illuminates events in primate evolution from ancient to recent, clarifying numerous taxonomic controversies and providing new data on human evolution. Ongoing speciation, reticulate evolution, ancient relic lineages, unequal rates of evolution, and disparate distributions of insertions/deletions among the reconstructed primate lineages are uncovered. Our resolution of the primate phylogeny provides an essential evolutionary framework with far-reaching applications including: human selection and adaptation, global emergence of zoonotic diseases, mammalian comparative genomics, primate taxonomy, and conservation of endangered species.

Photographic Maps of the Primates of Kenya and Tanzania: A Tool for Identification and Conservation

Abstract: The design and implementation of effective conservation measures for primates requires an efficient and accessible resource for the identification of species and subspecies. A total of 487 photographs (June 2010) on five on-line maps, called ‘Photographic Maps’ (or ‘PhotoMaps’), present the phenotypic characters for 15 species and 26 subspecies of primates at 82 sites in Kenya and Tanzania. The PhotoMaps, at , provide a ‘living’ collection of photographs. More photographs will be uploaded as they become available. PhotoMaps are a practical tool for documenting and discussing primate diversity, taxonomy, biogeography, distribution and conservation status and, therefore, for developing and implementing actions for primate conservation. The use of photographs to document phenotypic characters will become increasingly important as the collection of specimens for hands-on assessments becomes ever more difficult.

Genotyping of TRIM5 locus in northern pig-tailed macaques (Macaca leonina), a primate species susceptible to Human Immunodeficiency Virus type 1 infection

BackgroundThe pig-tailed macaques are the only Old World monkeys known to be susceptible to human immunodeficiency virus type 1 (HIV-1) infection. We have previously reported that the TRIM5-Cyclophilin A (TRIMCyp) fusion in pig-tailed macaques (Macaca nemestrina) is dysfunctional in restricting HIV-1, which may explain why pig-tailed macaques are susceptible to HIV-1 infection. Similar results have also been reported by other groups. However, according to the current primate taxonomy, the previously reported M. nemestrina are further classified into three species, which all belong to the Macaca spp. This calls for the need to look into the previous studies in more details.ResultsThe local species Northern pig-tailed macaque (M. leonina) was analyzed for the correlation of TRIM5 structure and HIV-1 infection. Eleven M. leonina animals were analyzed, and all of them were found to possess TRIM5-CypA fusion at the TRIM5 locus. The transcripts encoding the dysfunctional TRIM5-CypA should result from the G-to-T mutation in the 3'-splicing site of intron 6. Polymorphism in the putative TRIMCyp recognition domain was observed. The peripheral blood mononuclear cells (PBMCs) of M. leonina were susceptible to HIV-1 infection. Consistent with the previous results, expression of the M. leonina TRIMCyp in HeLa-T4 cells rendered the cells resistant to HIV-2ROD but not to SIVmac239 infection.ConclusionThe susceptibility of M. leonina to HIV-1 infection is due to the dysfunctional TRIM5-CypA fusion in the TRIM5 locus. This finding should broaden our perspective in developing better HIV/AIDS non-human primate animal models.

Lemur Diversity in Madagascar

A basic understanding of the taxonomy, diversity, and distributions of primates is essential for their conservation. This review of the status of the taxonomy of lemurs is based on a 5-d workshop entitled “Primate Taxonomy for the New Millennium,” held at the Disney Institute, Orlando, Florida, in February 2000. The aim is not to present a taxonomic revision, but to review our current understanding of the diversity and current and past ranges of lemurs and indicate where there is controversy, discrepancy, or lack of knowledge. Our goal therefore is to provide a baseline for future taxonomic investigation, as well as a clearer focus for research and conservation priorities. We here focus on the lemurs of Madagascar and recognize 5 families, 15 genera, and 99 species and subspecies. We list 39 species of lemurs described since 2000: 2 dwarf lemurs, Cheirogaleus; 11 mouse lemurs, Microcebus; a giant mouse lemur, Mirza; a bamboo lemur, Hapalemur; 17 sportive lemurs, Lepilemur; and 7 woolly lemurs, Avahi. Taxonomic revisions have resulted in the resurrection of a further 9 taxa. However, the figures do not represent the total diversity of Malagasy lemurs because more new species are being identified via new field studies and accompanying genetic research, and should be described in the near future.

Early Eocene Paromomyidae (Mammalia, Primates) from the southern Bighorn Basin, Wyoming: Systematics and evolution

We present a critical review of the alpha taxonomy and evolution of Eocene North American paromomyid primates, based on analysis of more than 570 stratigraphically controlled dental and gnathic specimens from the early Eocene of the southern Bighorn Basin, Wyoming (Wasatchian, Willwood Formation). In addition to documenting numerous previously unpublished specimens of known taxa (including deciduous teeth), we also describe a new species, Phenacolemur willwoodensis n. sp., from the upper part of the Willwood Formation (Wa 5 and 6). The new species is intermediate in size between Phenacolemur simonsi and Phenacolemur citatus and has both primitive features (e.g., retention of m2–3 paraconids, relatively long molar trigonids) and derived traits (e.g., relatively reduced paraconid on m1 and no p4 paracristid, unlike Paromomys). Overall patterns of dental evolution in southern Bighorn Basin paromomyids provide some support for previously hypothesized periods of faunal change (Biohorizons). In particular, Phenacolemur praecox evolves into the similarly sized but morphologically distinct Phenacolemur fortior at Biohorizon A, and P. fortior is replaced by P. citatus just below Biohorizon B. Two taxa previously believed to have become extinct at Biohorizon A (Ignacius graybullianus, P. simonsi) are shown to have persisted about a million years longer than previously thought. The Bighorn Basin paromomyids are of general interest in comprising a very dense sample that allows for the study of patterns of evolution against the backdrop of well-understood patterns of change in other mammalian lineages, and in climatic variables.

Early Eocene Paromomyidae (Mammalia, Primates) from the southern Bighorn Basin, Wyoming: Systematics and evolution

We present a critical review of the alpha taxonomy and evolution of Eocene North American paromomyid primates, based on analysis of more than 570 stratigraphically controlled dental and gnathic specimens from the early Eocene of the southern Bighorn Basin, Wyoming (Wasatchian, Willwood Formation). In addition to documenting numerous previously unpublished specimens of known taxa (including deciduous teeth), we also describe a new species,Phenacolemur willwoodensisn. sp., from the upper part of the Willwood Formation (Wa 5 and 6). The new species is intermediate in size betweenPhenacolemur simonsiandPhenacolemur citatusand has both primitive features (e.g., retention of m2–3 paraconids, relatively long molar trigonids) and derived traits (e.g., relatively reduced paraconid on m1 and no p4 paracristid, unlikeParomomys). Overall patterns of dental evolution in southern Bighorn Basin paromomyids provide some support for previously hypothesized periods of faunal change (Biohorizons). In particular,Phenacolemur praecoxevolves into the similarly sized but morphologically distinctPhenacolemur fortiorat Biohorizon A, andP. fortioris replaced byP. citatusjust below Biohorizon B. Two taxa previously believed to have become extinct at Biohorizon A(Ignacius graybullianus, P. simonsi)are shown to have persisted about a million years longer than previously thought. The Bighorn Basin paromomyids are of general interest in comprising a very dense sample that allows for the study of patterns of evolution against the backdrop of well-understood patterns of change in other mammalian lineages, and in climatic variables.

Primate chromosome evolution: Ancestral karyotypes, marker order and neocentromeres

In 1992 the Japanese macaque was the first species for which the homology of the entire karyotype was established by cross-species chromosome painting. Today, there are chromosome painting data on more than 50 species of primates. Although chromosome painting is a rapid and economical method for tracking translocations, it has limited utility for revealing intrachromosomal rearrangements. Fortunately, the use of BAC-FISH in the last few years has allowed remarkable progress in determining marker order along primate chromosomes and there are now marker order data on an array of primate species for a good number of chromosomes. These data reveal inversions, but also show that centromeres of many orthologous chromosomes are embedded in different genomic contexts. Even if the mechanisms of neocentromere formation and progression are just beginning to be understood, it is clear that these phenomena had a significant impact on shaping the primate genome and are fundamental to our understanding of genome evolution. In this report we complete and integrate the dataset of BAC-FISH marker order for human syntenies 1, 2, 4, 5, 8, 12, 17, 18, 19, 21, 22 and the X. These results allowed us to develop hypotheses about the content, marker order and centromere position in ancestral karyotypes at five major branching points on the primate evolutionary tree: ancestral primate, ancestral anthropoid, ancestral platyrrhine, ancestral catarrhine and ancestral hominoid. Current models suggest that between-species structural rearrangements are often intimately related to speciation. Comparative primate cytogenetics has become an important tool for elucidating the phylogeny and the taxonomy of primates. It has become increasingly apparent that molecular cytogenetic data in the future can be fruitfully combined with whole-genome assemblies to advance our understanding of primate genome evolution as well as the mechanisms and processes that have led to the origin of the human genome.

Molecular phylogeny and biogeography of langurs and leaf monkeys of South Asia (Primates: Colobinae)

The two recently proposed taxonomies of the langurs and leaf monkeys (Subfamily Colobinae) provide different implications to our understanding of the evolution of Nilgiri and purple-faced langurs. Groves (2001) [Groves, C.P., 2001. Primate Taxonomy. Smithsonian Institute Press, Washington], placed Nilgiri and purple-faced langurs in the genus Trachypithecus, thereby suggesting disjunct distribution of the genus Trachypithecus. [Brandon-Jones, D., Eudey, A.A., Geissmann, T., Groves, C.P., Melnick, D.J., Morales, J.C., Shekelle, M., Stewart, C.-B., 2003. Asian primate classification. Int. J. Primatol. 25, 97–162] placed these langurs in the genus Semnopithecus, which suggests convergence of morphological characters in Nilgiri and purple-faced langurs with Trachypithecus. To test these scenarios, we sequenced and analyzed the mitochondrial cytochrome b gene and two nuclear DNA-encoded genes, lysozyme and protamine P1, from a variety of colobine species. All three markers support the clustering of Nilgiri and purple-faced langurs with Hanuman langur ( Semnopithecus), while leaf monkeys of Southeast Asian ( Trachypithecus) form a distinct clade. The phylogenetic position of capped and golden leaf monkeys is still unresolved. It is likely that this species group might have evolved due to past hybridization between Semnopithecus and Trachypithecus clades.