Systematics of Neotropical Spiny Mice, Genus Neacomys Thomas, 1900 (Rodentia: Cricetidae), from Southeastern Amazonia, with Descriptions of Three New Species

Abstract

Species of Neacomys are small cricetid rodents that occur in forested habitats of Central and South America, from eastern Panama to central Bolivia and central/western Brazil. In order to assess species diversity of this poorly known genus, we obtained cytochrome b gene sequences from the most comprehensive taxonomic and geographic sampling analyzed to date. We also conducted morphological analyses on a large series of specimens housed in 15 museums, including types of 10 out of 14 nominal taxa. Our analyses of the genetic data recovered 17

Genetic diversity analysis in the Brazilian Amazon reveals a new evolutionary lineage and new karyotype for the genus Mesomys (Rodentia, Echimyidae, Eumysopinae)

“…Recent studies have described new species for the Tapajós region, corroborating its characterization as an endemic area, increasing the number of endemic species of different taxonomic groups for the region, including small non-flying mammals [ 39 – 42 ]. Some of these studies proposed the hypothesis that the Amazon rivers act as a geographic barrier, being the main factor that isolated the populations, influencing the differentiation of the species that occur in this area of endemism [ 41 – 44 ].…”

Systematic Revision of Thomasomys cinereus (Rodentia: Cricetidae: Sigmodontinae) from Northern Peru and Southern Ecuador, With Descriptions of Three New Species

“…Among other currently deficient data, several additional species remain to be described (Pacheco (2003, 2015; Lee et al, 2018; Brito et al, 2019; Brito et al, 2021; Ruelas and Pacheco, 2021a), mostly in the Aureus and Cinereus groups. The discovery of new species is not unexpected because analyses of molecular sequence data have revealed the existence of cryptic species in several other sigmodontine genera, including Neacomys (Sánchez-Vendizú et al, 2018; Semedo et al, 2020), Nephelomys (Ruelas et al, 2021), and Rhipidomys (Brito et al, 2017). This taxonomic research and accumulating new records of Thomasomys (e.g., Moreno-Cárdenas and Novillo-Gonzalez, 2020; Pacheco, 2021) are improving our knowledge of the diversity and distribution of the genus, but we are still far from a comprehensive analysis of diversification and biogeography of these quintessentially montane-forest rodents .…”

New species of the Spiny Mouse genus Neacomys (Cricetidae, Sigmodontinae) from northwestern Ecuador

“… Neacomys is a widely distributed genus of small spiny or bristly rodents that collectively occupy representative regions and habitats in easternmost Panama and the northern half of South America ( Patton et al 2015 ; Pardiñas et al 2017 ; Caccavo and Weksler 2021 ; Semedo et al 2021 ). Currently, 23 species are recognized within this group, occurring its highest concentration in the rainforests of the Amazon region ( Hurtado and Pacheco 2017 ; Semedo et al 2020 , 2021 ; Brito et al 2021a ; Caccavo and Weksler 2021 ).…”