The Phyllotis xanthopygus complex (Rodentia, Cricetidae) in central Andes, systematics and description of a new species

Abstract

Phyllotis Waterhouse 1837 is one of the most studied genera of South American cricetid rodents. As currently understood, it includes 20 small to medium‐sized species of predominantly rocky habitats. Among them, populations of the yellow‐rumped leaf‐eared mouse, traditionally referred to P. xanthopygus (Waterhouse 1837), are the most widely distributed, extending from central Peru to southern Chile and Argentina. Based mostly on molecular evidence, previous studies suggested that P. xanthopygus constitutes a species complex, being characterized by geographically structured and genetically divergent clades. In this work, we compare the molecular phylogenetic hypothesis for populations distributed on the eastern slopes of the central Andes with morphometric evidence using univariate and multivariate analyses. Quantitative morphological and molecular evidence suggests that at least four nearly cryptic species of the P. xanthopygus complex occur from southern Bolivia to west‐central Argentina. Three of these taxa have available names; one of them, P. caprinus, is currently recognized to the species level; the other two, the clades of P. x. posticalis‐P. x. rupestris and P. vaccarum, are both recognized as subspecies of P. xanthopygus. The remaining taxon represents a new species distributed in the west‐central Andes of Argentina. We discuss our morphological results in the light of other sources of evidence (e.g. qualitative and quantitative state characters, genetic and phylogenetic studies, and cytogenetic data) and name the new species as P. pehuenche, honouring the original native people that historically inhabited west‐central Andes of Argentina.

Late-Holocene environmental conditions revealed by a small mammal assemblage in mountain areas of Northwestern Argentina

“…Our conclusions would not have been possible without the noteworthy increase in knowledge on taxonomy, distribution, ecological requirements and fossil record of small mammals of the region in recent years, which begins to show general trends on the evolution of these communities in the Quaternary and their close connection with the environmental changes (e.g. d’Hiriart et al, 2015, 2017, 2021a, 2021b; Gomez et al, 2012; Guilardi et al, 2020; Jayat et al, 2007, 2008a, 2008b, 2010, 2011, 2016, 2017, 2018, 2020, 2021; Nanni et al, 2012; Ortiz et al, 2000, 2011a, 2011b, 2012, 2019; Ortiz and Jayat, 2007a, 2012; Ortiz and Pardiñas, 2001; Ortiz-Tempel et al, 2022; Teta et al, 2011, 2013, 2022, 2023). Nevertheless, although several Quaternary small mammal assemblages were described for NWA from different periods, our knowledge about short-, medium-, and long-term changes in these communities is still incipient.…”

“…The taxonomy of the species follows that proposed by Teta et al (2018), with exceptions indicated in each particular case (e.g. Jayat et al, 2021). Species richness and diversity values for Late-Holocene and modern small mammal assemblages (Table 1) were expressed using the following index and estimators: number of species (S), the nonparametric estimator Chao 1, and the Shannon index (H).…”

Host specificity of flea parasites of mammals from the Andean Biogeographic Region

“…The former host is endemic to Chile (Mammal Diversity Database, 2022). Regarding P. xanthopygus , recent studies suggested that constitutes a species complex (Ojeda et al, 2021), widely distributed (having the largest altitudinal range of any vertebrate, 6000 km range), occurring from central Peru to southern Chile and Argentina (Jayat et al, 2021). T. bonneti shows a preference for the genus Phyllotis and, although Beaucournu et al (2012) collected various other small mammals (marsupials and rodents) from the localities listed for this flea, all specimens captured were negative.…”

Genomic and radiocarbon insights into the mystery of mouse mummies on the summits of >6000 m Andean volcanoes

“…No reuse allowed without permission. the Andean Altiplano and adjoining regions of South America, geographic patterns of mitochondrial DNA variation have been well-characterized within and among species 4,[9][10][11][12] , so genomic sequence data should reveal whether summit mummies were derived from local source populations or whether they represent phylogeographic anomalies that trace their origins to more distant corners of the former Incan empire. Radiocarbon dating permits an even more conclusive test of the Incan transport hypothesis, since the Incan presence in this region is thought to have begun sometime after 1470, lasting until the initial years of the Spanish conquest in 1532 7,13 .…”