Ancient DNA of the pygmy marmoset type specimen Cebuella pygmaea (Spix, 1823) resolves a taxonomic conundrum

Zool Res. 2021 Nov 18;42(6):761-771. doi: 10.24272/j.issn.2095-8137.2021.143.

Abstract

The pygmy marmoset, the smallest of the anthropoid primates, has a broad distribution in Western Amazonia. Recent studies using molecular and morphological data have identified two distinct species separated by the Napo and Solimões-Amazonas rivers. However, reconciling this new biological evidence with current taxonomy, i.e., two subspecies, Cebuella pygmaea pygmaea (Spix, 1823) and Cebuella pygmaea niveiventris (Lönnberg, 1940), was problematic given the uncertainty as to whether Spix's pygmy marmoset ( Cebuella pygmaea pygmaea) was collected north or south of the Napo and Solimões-Amazonas rivers, making it unclear to which of the two newly revealed species the name pygmaea would apply. Here, we present the first molecular data from Spix's type specimen of Cebuella pygmaea, as well as novel mitochondrial genomes from modern pygmy marmosets sampled near the type locality (Tabatinga) on both sides of the river. With these data, we can confirm the correct names of the two species identified, i.e., C. pygmaea for animals north of the Napo and Solimões-Amazonas rivers and C. niveiventris for animals south of these two rivers. Phylogenetic analyses of the novel genetic data placed into the context of cytochrome b gene sequences from across the range of pygmy marmosets further led us to re-evaluate the geographical distribution for the two Cebuella species. We dated the split of these two species to 2.54 million years ago. We discuss additional, more recent, subdivisions within each lineage, as well as potential contact zones between the two species in the headwaters of these rivers.

作为全球最小的类人猿, 倭狨在西亚马逊分布极广。近期整合分类学研究表明,目前认为的“倭狨”实际代表了两个独立的物种,二者分布以纳波河-索利蒙伊斯河为界,而其目前的两个亚种应提升为有效种。然而,由于倭狨指名亚种的模式产地相较河流的具体位置不明,因此难以确定两个已有学名与演化支系间的具体对应关系。在此,该研究首次提供了倭狨指名亚种模式标本的DNA分子数据,同时提供了模式产地界河两侧个体的线粒体基因组数据。基于上述数据,该研究确定了河流北部的狨猴种群对应真正的倭狨 Cebuella pygmae,而河流南部种群则对应新提升有效性的东部倭狨 C. niveiventris。结合已有的线粒体细胞色素b数据,研究重新厘定了两种的分布情况,同时推算两种倭狨的分化时间约为2.54百万年前。最后,该研究讨论了分类厘定后种内的近期种群分化,以及两种在河流上游可能存在的接触区域。.

Keywords: Amazon; C. niveiventris; Cebuella pygmaea; DNA taxonomy; Historic DNA; Pygmy marmoset; Type specimen.

MeSH terms

  • Animal Distribution
  • Animals
  • Brazil
  • Callitrichinae / classification*
  • Callitrichinae / genetics*
  • DNA, Mitochondrial / genetics*
  • Phylogeny*
  • Species Specificity

Substances

  • DNA, Mitochondrial

Associated data

  • GENBANK/MW733803-MW733806, MZ747451-MZ747454

Grants and funding

This study was supported by the Conselho Nacional de Pesquisa, Brazil (563348/2010), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (3261/2013), NSF (1241066), FAPESP (12/50260-6) and NERC (NE/T000341/1)