Sunday, December 31, 2023

[Mammalogy • 2023] Ctenomys pulcer • A New Species of the highly polytypic South American Rodent Ctenomys (Ctenomyidae) increases the Diversity of the magellanicus clade


Ctenomys pulcer 
Verzi, De Santi, Olivares, Morgan, Basso & Brook, 2023


Abstract
The subterranean rodent Ctenomys is the most polytypic South American mammal genus and one of the most speciose and rapidly diversifying mammal genera in the world. Its systematics is unstable due to the underlying accelerated diversification processes that give rise to evolutionary lineages at different stages of differentiation and to remarkable morphological homogeneity even among long-differentiated species. As a result, species boundaries are often difficult to define. Diversity of this genus in the coastal area of central Argentina has been extensively studied, with two independent lineages currently recognized while a distinct third population had not been previously detected. Through a phylogenetic analysis based on combined morphological and molecular evidence, Bayesian estimates of divergence times, and morphometric and morphological assessments, we recognize this third population as an independently evolving lineage. The new species, Ctenomys pulcer sp. nov., is here described for both the living fauna and the fossil record of the Pampean region of central Argentina. According to phylogenetic results, Ctenomys pulcer sp. nov. belongs to the essentially Patagonian magellanicus clade, and would have diverged from its sister species, Ctenomys bidaui, during the middle Pleistocene (ca. 0.4 Ma). Its current distribution in the fixed and semifixed dunes of the coastal Pampean region is assumed to represent a relict of a wider and continuous distribution of potentially suitable environments during the late Pleistocene. Ctenomys pulcer sp. nov. occurs in a particularly fragile natural system subjected to profound disturbances caused by diverse anthropic actions and therefore measures for the conservation of its habitat will be indispensable.

Keywords: Ctenomyidae, early Holocene-Recent, Pampean region, phylogeny, systematics


Superfamily Octodontoidea Waterhouse, 1839

Family Ctenomyidae Lesson, 1842

Genus Ctenomys Blainville, 1826



Ctenomys pulcer sp. nov.

Etymology: From Latin pulcer, in Spanish hermoso (beautiful) in reference to the type locality Monte Hermoso.


 
Diego H. Verzi, Nahuel A. De Santi, A. Itatí Olivares, Cecilia C. Morgan, Néstor G. Basso and Federico Brook. 2023. A New Species of the highly polytypic South American Rodent Ctenomys increases the Diversity of the magellanicus clade. Vertebrate Zoology. 73: 289-312. DOI: 10.3897/vz.73.e96656
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