Evolution and biogeographic history of the Saguinus mystax group (Primates, Callithrichidae)

Abstract

The Saguinus mystax group traditionally includes three species, S. mystax, S. labiatus, and S. imperator. The additional inclusion of S. inustus is argued on molecular grounds, which have an important impact on our comprehension of the phenotypical evolution and biogeography of the group. Here, we investigate the evolutionary events leading to the diversification of the S. mystax group, integrating phylogenetic, temporal, and geographic information with the current knowledge of the Amazonian paleogeographical history. The examination of 208 specimens of Saguinus resulted in 25 morphological characters, of which 13 were used for the first time in a phylogenetic analysis of the genus. Morphological characters were also combined with molecular data and analyzed using Bayesian and Maximum Likelihood methods. Trees resulting from morphological and combined data recovered a monophyletic S. mystax group, including S. inustus, whose inclusion was supported by two morphological synapomorphies. Molecular based age estimates place the origin of Saguinus in the middle Miocene (17.4-13 million years ago [mya]), whereas the S. mystax group originated in an interval between 12 and 6 mya. Our results also suggest that the ancestral area of Saguinus was western Amazon, from where they dispersed to their current distribution after the end of the Pebas lakes system. The diversification events in the S. mystax group are related to the Pliocene development of the modern Amazon river network associated to the uplift of Fitzcarrald Arch.

Taxonomic status of Tamarinus imperator subgrisescens (Lönnberg, 1940) (Cebidae, Callitrichinae)

“…Although there are many phylogenetic hypotheses for tamarins (Jacobs et al, 1998;Cropp et al, 1999;Tagliaro et al, 2005;Matauschek et al, 2011;Cunha et al, 2011;Buckner et al, 2015;Athaydes et al, 2021;Brcko et al, 2022), the most of last taxonomic decisions, that is, the delimitation of species was not based on those phylogenies and has used the distinguishability criteria to define the taxa. Currently, tamarins comprise 22 species and 20 subspecies (Rylands et al, 2016).…”

Molecular systematics of tamarins with emphasis on genusTamarinus(Primates, Callitrichidae)

“…Only Araripe et al (2008) enclosed both species in their study, and two significant lineages were found, suggesting the existence of two species. Furthermore, the most recent phylogenetics studies could not clarify the taxonomy of these species (Athaydes et al, 2021; Brcko et al, 2022).…”

“…Recent phylogenetics studies could not clarify the taxonomy of these species as only T . subgrisescens were analysed (Athaydes et al, 2021; Brcko et al, 2022). Only Araripe et al (2008) enclosed both species in their study, and two significant lineages were found, suggesting the existence of two species.…”

“…Thus, after analysing other specimens of T. imperator, Hershkovitz (1979) realized that the phenotypes were different and that they were two subspecies. Recent phylogenetics studies could not clarify the taxonomy of these species as only T. subgrisescens were analysed (Athaydes et al, 2021;Brcko et al, 2022). Only Araripe et al (2008) enclosed both species in their study, and two significant lineages were found, suggesting the existence of two species.…”

“…For genus Saguinus sensu Buckner et al (2015), some studies also consistently recovered the Saguinus bicolor + S. midas, Saguinus mystax + S. inustus and Saguinus oedipus groups (Athaydes et al, 2021;Brcko et al, 2022;Buckner et al, 2015). However, only Brcko et al (2022) proposed to classify the Saguinus bicolor + midas, Saguinus mystax+inustus and Saguinus oedipus groups as the genera Saguinus Hoffmannsegg, 1807, Tamarinus Trouessart, 1904and Oedipomidas Reichenbach, 1862, respectively.…”