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

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.

Two hundred and five newly assembled mitogenomes provide mixed evidence for rivers as drivers of speciation for Amazonian primates

“…That said, additional support for the Amazon as a species barrier for pygmy marmosets ( Cebuella spp.) has recently been provided (Boubli et al, 2021; Porter et al, 2021). Notably, many divergences across the Amazon did not occur synchronously and/or postdate the known minimum time of river formation.…”

Taxonomic review ofSaguinus mystax(Spix, 1823) (Primates, Callitrichidae), and description of a new species

“…Much of the taxonomy of Amazonian primates is based on the seminal work of Hershkovitz (1977) and has not changed much in the last 45 years. As genomic data becomes more accessible, including data from centuries-old type specimens ( Boubli et al, 2021 ), and as new biodiversity surveys and scientific collections provide new material for rigorous and biologically realistic analyses, our understanding of the taxonomic diversity of Amazonian primates will change ( e.g ., Boubli et al, 2018 , 2019 ; Costa-Araújo et al, 2019 , 2021 ). These taxonomic changes will not be the consequence of taxonomic inflation, but rather will reflect the underlying evolutionary and speciation processes that have generated and are generating the immense Amazonian biodiversity.…”

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

“…A phylogenetic study by Boubli et al (2018) showed that the forms Cebuella pygmaea Spix (from the north of the Solimões-Amazonas) and Cebuella niveiventris Lönnberg (from the south of the Rio Solimões-Amazonas) were distinct species. The type locality for Cebuella pygmaea, as given by Spix, was ambiguous but Garbino et al (2019) and Boubli et al (2021) concluded that it is the form to the north of the rios Amazonas-Solimões and Napo, with C. niveiventris being the correct name for the species south of these rivers. Porter et al (2021) confirmed the conclusions of Garbino et al (2019) and Boubli et al (2021) for Ecuador and Peru.…”

“…The type locality for Cebuella pygmaea, as given by Spix, was ambiguous but Garbino et al (2019) and Boubli et al (2021) concluded that it is the form to the north of the rios Amazonas-Solimões and Napo, with C. niveiventris being the correct name for the species south of these rivers. Porter et al (2021) confirmed the conclusions of Garbino et al (2019) and Boubli et al (2021) for Ecuador and Peru. Garbino (2014) reported that Mico manicorensis (Van Roosmalen et al, 2000) was a junior synonym of Mico marcai (Alperin, 1993), previously known only from its type locality on the west bank of the Rio Aripuanã, near the mouth of the Rio Roosevelt.…”