A new species of Mindomys (Rodentia, Cricetidae) with remarks on external traits as indicators of arboreality in sigmodontine rodents

Abstract

The diversity of the oryzomyine rat Mindomys (Cricetidae, Sigmodontinae, Oryzomyini), is doubled here with the description of a new species from the remote Cordillera de Kutukú (Ecuador). The novel form can be easily differentiated from Mindomys hammondi –type species of the genus– by a large set of anatomical traits including, among others, larger jugals, parietal “wings” extending to zygomatic roots, larger otic capsules, well-exposed petrosals, narrow zygomatic plates almost without upper free borders, foramen magnum caudally oriented, larger molars, and accessory root of first upper molar present. Until now, the records of Mindomys were restricted to western Andean foothills. The material from Kutukú highlights an Amazonian species and reinforces the valuable biological significance of isolated mountain ranges in eastern Ecuador. Since Mindomys shows some external traits classically related to arboreal life, here we present a brief reappraisal of this poorly explored topic. A partially neglected anatomical system in sigmodontine studies, the fore feet, encloses crucial information reflecting arboreality.

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

“…The interest in complementary biodiversity studies has led to the prioritization of intensive field work, using a variety of trapping techniques (e.g., live traps, spring traps, and pitfall traps), and has also triggered revisions of museum specimens. For example, in the last five years, these approaches have led to the description of at least 14 new sigmodontine: five Chilomys (see Brito et al, 2022a ), three Thomasomys (see Brito et al 2019 ; Brito et al 2021b ; Lee et al 2022 ), one Tanyuromys (see Timm et al 2018 ), one Ichthyomys (Fernández de Córdova et al 2020), two Pattonimus ( Brito et al 2020 ), one Neacomys ( Brito et al 2021a ), and one Mindomys ( Brito et al 2022b ). This burgeoning richness will surely reorganize part of our understanding of Neotropical cricetids.…”

Morphological and Genetics Support for a Hitherto Undescribed Spotted Cat Species (Genus Leopardus; Felidae, Carnivora) from the Southern Colombian Andes

“…This may be the case for the 12 alleged "new species" of gracile capuchins (Cebus) [3], or the cases of Mazama bricenii [4], Nasuella meridensis [5], Odocoileus lasiotis [6,7], Pecari maximus [8], Inia araguaiaensis [9], and Tapirus kabomani [10][11][12]. On the other hand, there is strong evidence to support the recognition of other new mammal species in the Neotropics, for example, Bradypus pygmaeus [13], Bassarycion neblina [14], Mico humilis [15], Mico munduruku [16], Mico schneideri [17], Myotis attenboroughi [18], Mindomys kutuku [19], and different species of Cyclopes (for instance, Cyclopes rufus, Cyclopes thomasi, etc.) (Miranda et al, 2018) [20] to cite a few.…”