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On-line version ISSN 2007-3364

Therya vol.9 n.1 La Paz Jan. 2018 


Rodents of the eastern and western slopes of the Tropical Andes: phylogenetic and taxonomic insights using DNA barcodes

C. Miguel Pinto1  * 

Reed Ojala-Barbour1  2 

Jorge Brito1  3 

Angélica Menchaca4 

André L. G. Carvalho5 

Marcelo Weksler6  7 

George Amato8 

Thomas E. Lee Jr.9 

1 Instituto de Ciencias Biológicas, Escuela Politécnica Nacional, Av. Ladrón de Guevara E11-253. Casilla: 17-01-2759. Quito, Ecuador. Email: (CMP), (JB).

2 Washington Department of Fish and Wildlife, Headquarters, 1111 Washington St. SE, WA 98501, Olympia. Washington, U. S. A. Email: (ROB).

3 Museo Ecuatoriano de Ciencias Naturales del Instituto Nacional de Biodiversidad, División de Mastozoología. Calle Rumipamba 341 y Av. de los Shyris. Casilla: 17-07-8976. Quito, Ecuador.

4 School of Biological Sciences, University of Bristol, 24 Tyndall Ave, Bristol BS8 1TH, United Kingdom. Email: (AM).

5 Laboratório de Herpetologia, Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo (USP), Rua do Matão, Travessa 14, Número 101 05508-090, Cidade Universitária São Paulo Brazil. Email: (ALGC).

6 Laboratório de Ecoepidemiologia da Doença de Chagas, Instituto Oswaldo Cruz, Fiocruz, Avenida Brasil 4365, 21045-900. Rio de Janeiro, Brazil. Email: (MW)

7 Departamento de Vertebrados, Museu Nacional, Universidade Federal do Rio de Janeiro, Quinta da Boa Vista, São Cristóvão, 20940-040. Rio de Janeiro, Brazil

8 Sackler Institute for Comparative Genomics, American Museum of Natural History. Central Park West @ 79th St. New York10024. New York, U. S. A. Email: (GA).

9 Department of Biology, Box 27868, Abilene Christian University, 1600 Campus Court, Abilene 79699-27868. Texas, U. S. A. Email: (TEL)


The Andes Mountains particularly the forests along the mid-elevations of their eastern and western slopes, are a hotspot of biodiversity (high numbers of species and endemics). Among mammals, rodents are a priority group for study in the Tropical Andes given their high diversity and often relatively small geographic ranges. Here, we use DNA barcoding as a tool to help in the identification, and preliminary analysis of the phylogenetic relationships, of rodents from two natural reserves: Otonga, a private forest reserve, located on the western slopes, and Sangay National Park, located on the eastern slopes of the Ecuadorian Andes. We sequenced 657 bp of the mitochondrial Cytochrome Oxidase I (COI) gene for 201 tissue samples of sigmodontine and echimyid rodents collected primarily in Otonga and Sangay. We conducted phylogenetic analyses using maximum-likelihood and Poisson tree processes (PTP) species delimitation analyses. Three sets of data were analyzed: 1) our newly generated sequences, 2) our Mesomys sequence plus DNA sequences of Echimyidae available in GenBank, and 3) all of our sequences (all Sigmodontinae and one Echimyidae) together with relevant DNA sequences of Sigmodontinae available in GenBank. Our samples consisted of 24 species; the molecular data indicated that only one species—Microryzomys minutus—was shared between both eastern and western localities. Contrary to the currently recognized distributions of Akodon mollis and Chilomys instans, our species delimitation analysis suggests that these species are not shared between Otonga and Sangay, and may actually represent two species each. The sample of Mesomys from the eastern slopes of the Andes differs minimally from that from the lowlands of the Ecuadorian Amazon, suggesting that both populations would correspond to the same species, Mesomys hispidus. Both Mindomys hammondi and an undescribed Mindomys from Otonga do not form a reciprocally monophyletic group with relation to Nephelomys. The Nephelomys of Sangay might correspond to two different species. The eastern and western slopes of the Tropical Andes harbor different species of rodents, with only one of our study species shared between both localities, implying that other cases of shared species between the eastern and the western slopes of the Andes need further assessment. Several lineages represented in our sample may require formal taxonomic description, highlighting the need for further systematic research. The new genetic data generated in our study could speed taxonomic discovery in the Andes and help to illuminate interesting evolutionary patterns, such as the radiation of Thomasomys.

Key words: Akodon; Andes; Chilomys; Echimyidae; Ecuador; Microryzomys; Oligoryzomys; Sigmodontinae; species delimitation; Thomasomys


Los Andes particularmente los bosques de las elevaciones medias de las estribaciones occidentales y orientales, son un punto caliente de biodiversidad (alto número de especies y de endemismo). Entre los mamíferos andinos, los roedores son un grupo prioritario a ser estudiado dada su alta biodiversidad y sus rangos de distribución que por lo general son pequeños. En esta contribución, usamos códigos de barras de ADN como una herramienta para la identificación y generación de hipótesis filogenéticas preliminares de los roedores colectados principalmente en dos reservas naturales: Otonga, ubicada en las estribaciones occidentales, y Sangay, localizada en las estribaciones orientales de los Andes ecuatorianos. Secuenciamos 657 pares de base del gen mitocondrial Citocromo Oxidasa I (COI) en 201 muestras de tejido de roedores sigmodontinos y echimyidos colectados principalmente en Otonga y Sangay. Hicimos análisis filogenéticos usando máxima verosimilitud, y análisis de delimitación de especies mediante el proceso de árboles de Poisson (PTP). Tres grupos de datos fueron analizados: 1) todas nuestras nuevas secuencias generadas, 2) nuestra secuencia de Mesomys más las secuencias de ADN de Echimiydae disponibles en GenBank, y 3) todas nuestras secuencias (mayoritariamente Sigmodontinae) junto con secuencias de ADN de Sigmodontinae disponibles en GenBank. Nuestra muestra contiene 24 especies; los datos moleculares demuestran que solo una especie—Microryzomys minutus—es compartida entre ambas localidades del este y oeste. Mientras que nuestro análisis de delimitación de especies sugiere que Akodon mollis y Chilomys instans no son compartidas entre Otonga y Sangay, y representan dos especies cada una. La muestra de Mesomys de la vertiente oriental de los Andes es mínimamente diferente de secuencias de las tierras bajas de la Amazonia ecuatoriana; recomendando que ambas poblaciones podrían corresponder a la misma especie, Mesomys hispidus. Mindomys hammondi y una especie no descrita de Mindomys de Otonga no forman un grupo monofilético en relación a Nephelomys. Los Nephelomys de Sangay corresponderían a dos especies diferentes. Las vertientes occidental y oriental de los Andes tropicales albergan especies diferentes de roedores, con una sola especie compartida entre ambas indicando que otros casos de especies compartidas entre el este y occidente necesitan ser investigadas con mayor detalle. Múltiples especies de nuestra muestra necesitarían descripción formal, lo que revela que se requiere más investigación sistemática en la región. Los nuevos datos genéticos aquí presentados podrían acelerar los descubrimientos taxonómicos en los Andes y ayudar a explorar patrones volutivos interesantes, como la radiación de los Thomasomys.

Key words: Akodon; Andes; Chilomys; Echimyidae; Ecuador; Microryzomys; Oligoryzomys; Sigmodontinae; species delimitation; Thomasomys


The Andes Mountains encompass diverse environments along their slopes, ranging from lowland forests to glacier-covered peaks at over 6,000 meters above the sea level (masl). These different environments harbor high levels of species diversity and endemism, and together they make the Andean region one of the most important diversity hotspots on the planet (Myers et al. 2000). The Andean rodent fauna is no exception to these environmental trends. Recent analyses have detected several hotspots of rodent diversity along the Andes, such as the eastern slopes in Ecuador and Peru (Prado et al. 2015; Maestri and Patterson 2016).

The systematics of Neotropical rodents is in a phase of rapid update and improvement, triggered especially by active efforts in Latin American countries to train taxonomic specialists (Voss 2009) and by the recent availability of a synthetic treatment of the entire rodent fauna of South America (Patton et al. 2015). However, many systematic relationships remain to be clarified, especially in clades of Andean rodents such as akodontines and thomasomyines, as well as some oryzomyines and echimyids. Such studies have been difficult to perform due to various limitations in past collecting and inventory work (Patterson 2002), and the logistic difficulties of visiting natural history museums in foreign countries to undertake revisionary work. These difficulties are evidenced, for example, in the data gaps for rodent sampling in various areas, such as in middle elevation forests near Papallacta in eastern Ecuador (Voss 2003).

The rodent fauna of the Andean slopes of northwestern South America is rich in species of Thomasomys. It is not uncommon to find large (e. g., T. aureus), medium (e. g., T. silvestris), small (e. g., T. baeops), and very small (e. g., T. cinnameus) species of the genus living in sympatry (Jarrín 2001; Pacheco 2003, 2015; Lee et al. 2011). Other components of the rodent fauna of the Andean forests include oryzomyines such as Microryzomys, Nephelomys, Oreoryzomys, and the enigmatic Mindomys hammondi, which is known from few specimens (Carleton and Musser 1989; Weksler 2006; Weksler et al. 2006).

The usage of molecular markers has been pivotal to accelerate and improve taxonomic work. One common approach has been the use of DNA barcodes—sequences of the mitochondrial gene COI—which have been applied successfully for facilitating identifications of specimens in Neotropical faunal surveys (Clare et al. 2007; Borisenko et al. 2008); however, this approach has not been used exhaustively with Andean mammals. Here, we use DNA barcoding as evidence to identify and conduct preliminary phylogenetic analysis of rodents from two natural reserves: Otonga, located in the western slopes of the Andes (cis-Andean), and Sangay National Park, located in the eastern slopes of the Andes (trans-Andean). Also, we explore whether populations shared between the eastern and western slopes of the Andes are likely to be conspecific, or alternately whether they represent divergent lineages that may not be recognized under current taxonomic classifications.

Materials and Methods

Sampling. We used selected samples of 21 species of rodents, primarily identified on the basis of morphological characters, collected in two Andean forests: Otonga, a private forest reserve located in the western slopes of the Andes in the province of Cotopaxi in northern Ecuador (Jarrín 2001), and Sangay National Park located in the eastern slopes of the Andes in the provinces of Chimborazo, Morona Santiago and Tungurahua in south-central Ecuador (Armstrong and Macey 1979; Fonseca et al. 2003; Figure 1). Three different field parties collected voucher specimens with tissues during 2006 in Otonga, and during 2010 and 2012 in Sangay. Morphological identifications of all specimens were conducted using specialized taxonomic literature (e. g., Carleton and Musser 1989; Weksler 2006; Patton et al. 2015), and by side-by-side comparisons with voucher specimens from the following collections: Abilene Christian University (ACUNHC) in Abilene, Texas, USA; American Museum of Natural History (AMNH) in New York, New York, USA; Escuela Politécnica Nacional (MEPN) in Quito, Ecuador; Museo Ecuatoriano de Ciencias Naturales (MECN) in Quito, Ecuador; National Museum of Natural History (NMNH) in Washington DC, USA; and Pontificia Universidad Católica del Ecuador (QCAZ) in Quito, Ecuador. Some previous findings of the mammals collected by these parties have been reported elsewhere (Lee et al. 2011; Helgen et al. 2013; Ojala-Barbour et al. 2013; Brito and Ojala-Barbour 2014; Brito et al. 2014; Brito et al. 2017). Examined specimens are housed at different mammal collections as indicated in Appendix 1.

Figure 1 Otonga Reserve and Sangay National Park, localities of the rodent specimens analyzed in this study. Otonga samples were collected by Helgen et al. (2013). For Sangay, points 1 and 2 correspond to localities near the Atillo Lagoon sampled by Lee et al. (2011); and points 3 to 5 correspond to localities sampled by J. Brito and R. Ojala-Barbour (Ojala-Barbour et al. 2013; Brito et al. 2014). Chimborazo and Cotopaxi volcanoes are labeled as points of reference. Inset: map of northwestern South America indicating in a black rectangle the expanded map. 

Laboratory work. We used the DNeasy kit (Qiagen, Valencia, California, USA), following the manufacturer´s protocol, to extract DNA of 201 samples of either liver or muscle from rodents collected in Otonga and Sangay. We performed PCR amplifications with the Illustra puReTaq Ready-To-Go PCR beads (GE Healthcare, Little Chalfont, Buckinghamshire, UK) to amplify a fragment of the mitochondrial COI gene using the “cocktail 2”—an M13-tailed primer cocktail optimized for mammals—with the primer ratios and thermal cycle conditions of Clare et al. (2007). We cleaned the PCR products with ExoSAP-IT (Affymetrix Inc., Santa Clara, California, USA), and conducted sequencing reactions with the ABI Big Dye chemistry (Applied Biosystems, Inc., Foster City, California, USA), using the primers M13F and M13R (Messing 1983). We sequenced the products on an ABI 3730xl DNA Analyzer automatic sequencer (Applied Biosystems, Inc., Foster City, California, USA). New sequences were deposited in GenBank (accession numbers: MF806172 – MF806372).

Phylogenetic analyses. We constructed three alignments: (A) an alignment containing our 201 newly generated sequences; (B) an alignment including our sample of Mesomys, a COI sequence of Chinchilla lanigera, and 614 sequences of the COI gene of members of the family Echimyidae (retrieved from the nucleotide database of GenBank searching for “Echimyidae COI”); C) an alignment including our 201 newly generated sequences plus 1,775 sequences of sigmodontinae rodents retrieved from Gen-Bank with the search terms “Sigmodontinae COI”. To align the sequences we used the MUSCLE (Edgar 2004) plugin in Geneious Pro v8.1.5 with default parameters. We checked the alignments manually for obvious misplacements, and trimmed all alignments to a length of 657 bp.

For each alignment we conducted phylogenetic analyses using maximum likelihood in RAxML v8 (Stamatakis 2014). We used the model GTRGAMMA for alignment A— tree A—(Figure 2) and the model GTRCAT for alignments B—tree B—(Figure 3) and C—tree C—(Figures 4 to 7)(5,6). For each analysis support values were estimated using 1,000 nonparametric bootstrap pseudo replicates. For analyses A and C we used as outgroup our sequence of Mesomys, and of Chinchilla lanigera for analysis B. For each RAxML analysis, we started with a complete alignment as described above to obtain the reduced alignment (a matrix without redundant haplotypes); later, we resumed the analysis with the reduced alignment and let it finish.

Figure 2 Maximum likelihood gene tree (tree A; see text) of unique haplotypes of the COI gene of the rodents collected in Otonga (West, W) and Sangay (East, E). Color of the branches indicates the results of the PTP species delimitation analysis: monophyletic groups in red indicate a single putative species as well as terminal branches in blue. Numbers associated with each putative species are supporting values of the PTP species delimitation; values of 1 indicate the highest possible support. Single plus symbols indicate main branches with moderate ML bootstrap values ≥75 %, and asterisks indicate main branches with strong ML bootstrap values ≥95 %. 

Figure 3 Maximum likelihood gene tree and PTP species delimitation of unique haplotypes of the COI gene of the rodents of the family Echimyidae available in GenBank plus the sample of Mesomys collected at Sangay in the eastern slopes of the Ecuadorian Andes (inset); main figure panel is a zoom-out of tree to depict only the genus Mesomys, showing two putative species within M. hispidus. Colors, symbols and support values correspond to the same as in Figure 2. Names of terminals indicate sample codes and geographic origin of the samples; sequences retrieved from GeneBank keep their original identifications. Star indicates the sample of Mesomys hispidus from Sangay. 

Figure 4 Maximum likelihood gene tree and PTP species delimitation of unique haplotypes of the COI gene of the rodents of the subfamily Sigmodontinae available in GenBank plus our sample (Appendix 1) collected in Otonga Reserve and Sangay National Park (inset). Main figure panels are zoom-outs of the three clades were appear representatives of Oligoryzomys. Colors, symbols and support values correspond to the same as in Figure 2. Names of terminals indicate sample codes; sequences retrieved from GeneBank keep their original identifications. Star indicates the samples of Oligoryzomys spodiurus from Ontonga. Oligoryzomys is depicted as a paraphyletic genus; this is regarded as a spurious result (see text). True Oligoryzomys is depicted in clade B. 

Figure 5 Maximum likelihood gene tree and PTP species delimitation of unique haplotypes of the COI gene of the rodents of the subfamily Sigmodontinae available in GenBank plus our sample (Appendix 1) collected at Otonga Reserve and Sangay National Park (inset). Main figure panel is a zoom-out of the Mindomys + Nepehelomys clade. Colors, symbols and support values correspond to the same as in Figure 2. Names of terminals indicate sample codes; sequences retrieved from GeneBank originally identified as N. albigularis were reclassified as N. devius and N. pirrensis based on their geographic origins. Stars indicate the species of Mindomys and Nephelomys sequenced for this study. 

Figure 6 Maximum likelihood gene tree and PTP species delimitation of unique haplotypes of the COI gene of the rodents of the subfamily Sigmodontinae available in GenBank plus all our samples included in Figure 2 collected in Otonga Reserve and Sangay National Park (inset); main figure panel is a zoom-out of the Hylaeamys clade. Colors, symbols and support values correspond to the same as in Figure 2. Names of terminals indicate sample codes; sequences retrieved from GeneBank keep their original identifications. Star indicates the sample of Hylaemays tatei from Sangay. Pound symbol indicates a very large clade of Hylaeamys megacephalus that was collapsed to obtain a clearer representation of this figure. Doted lines indicate branch lengths were reduced. 

Figure 7 Maximum likelihood gene tree and PTP species delimitation of unique haplotypes of the COI gene of the rodents of the subfamily Sigmodontinae available in GenBank plus all our samples included in Figure 2 collected in Otonga Reserve and Sangay National Park (inset); main figure panel is a zoom-out of the Rhipidomys clade. Colors, symbols and support values correspond to the same as in Figure 2. Names of terminals indicate sample codes; sequences retrieved from GeneBank keep their original identifications. Stars indicate the two species of unnamed Rhipidomys reported in this study. Pound symbol indicates a very large clade of Rhipidomys macconnelli that was collapsed to obtain a clearer representation of this figure. 

Species delimitation. We performed species delimitation analyses for the best maximum likelihood trees using the Poisson tree processes (PTP) method in the bPTP web server (Zhang et al. 2013). The PTP method was built as an operational criterion of the Phylogenetic Species Concept (Eldredge and Cracraft 1980). PTP is a fast and accurate species delimitation method that uses as input a non-ultrametric tree; PTP models speciation rates from the number of substitutions in a phylogeny, and expects to find statistically significant differences from intra and inter specific relationships (Zhang et al. 2013). PTP has been successfully applied to mammals and other organism such as trypanosome parasites (Cottontail et al. 2014; Ermakov et al. 2015; Bernal and Pinto 2016), and this method has been found to be more robust than the popular GMYC method that uses time divergences from ultrametric trees which are error prone and computationally expensive to estimate (Zhang et al. 2013; Tang et al. 2014). We ran the PTP analyses for 100,000 MCMC generations for tree A, 200,000 MCMC generations for tree B, and 400,000 generations for tree C. For all analyses we set the thinning value at 100, a burn-in of 0.1, and removed outgroups to improve species delimitation.


Our maximum likelihood gene tree A (Figure 2) recovered a paraphyletic tribe Thomasomyini (represented in our sample by Thomasomys, Chilomys, and Rhipidomys) relative to Akodon mollis; however, the members of the Oryzomyini were recovered as a monophyletic group (Figure 2). The maximum likelihood species delimitation analysis in PTP of tree A returned 24 candidate species. Even though we expected three shared species between both sides of the Andes (Figure 1), the molecular data supported that only one species—Microryzomys minutus—was shared between both eastern and western localities. In contrast, Akodon mollis, and Chilomys instans show structured variation, with percentage of difference >1.4 % between both putative species of Akodon and 7 % between the putative species of Chilomys. Also, our species delimitation suggests that Thomasomys taczanowskii is comprised of two putative species, both distributed in the Eastern slopes of the Andes; the divergence between both is 3 % (Figure 2).

The maximum likelihood gene tree of the family Echimyidae — tree B — (Figure 3) contained 281 unique terminals, and the maximum likelihood PTP analysis of species delimitation returned 42 candidate species. The sample of Mesomys from the eastern slopes of the Andes is nested with sequences of Yasuní National Park from the lowlands of the Ecuadorian Amazonia, confirming that both populations likely correspond to the same species (Figure 3).

The COI gene tree of the subfamily Sigmodontinae (tree C; Figures 4 to 7) (5, 6) consisted of 1,020 unique sequences, and the maximum likelihood species delimitation returned 153 candidate species. The genus Oligoryzomys was recovered as polyphyletic. The Otonga samples of Oligoryzomys destructor are sister to a clade of Oligoryzomys species including 6 candidate species within O. fulvescens and a sample identified as O. nigripes (Figure 4). The genera Mindomys and Nephelomys form a monophyletic group. However, the genus Mindomys (M. hammondi and an undescribed Mindomys from Otonga) was not recovered monophyletic (Figure 5). The specimens of Nephelomys from Sangay National Park might correspond to two different species, with a divergence of 5.6 %, and Nephelomys moerex from Otonga is sister to two Nephelomys species from Central America (Figure 5). The genus Hylaeamys was recovered as monophyletic and H. tatei was nested well inside the genus, as sister to a clade comprised of 6 candidate species currently identified within H. yunganus (Figure 6). Both species of Rhipidomys from Ecuador form a monophyletic group sister to a clade formed by R. scandens, R. leucodactylus (2 putative species), and R. nitela (Figure 7).


The DNA barcoding initiative was established as a fast and universal approach to speed the discovery and identification of species (e. g., Hebert et al. 2003; Hebert and Gregory 2005; Harris and Bellino 2013). However, using the mitochondrial COI gene as the marker of choice for mammals has faced resistance from researchers used to working mainly with the CYTB gene; this is shown by the asymmetric number of sequences for the two markers deposited in GenBank (as of December 31st, 2016 there are 37,101 and 136,965 sequences of the mammalian COI and CYTB genes, respectively). Also it has been argued that CYTB gene performs better in deeper nodes of phylogenies, and it seems more informative for discriminating species (Tobe et al. 2010); however, this stance has faced criticism, as it has been demonstrated that COI gene behaves similarly to CYTB gene (Nicolas et al. 2012), and various studies have successfully made use of COI gene for species identifications (e. g., Clare et al. 2007; Borisenko et al. 2008). Although, we are aware that single locus phylogenies are substandard, and well-accepted phylogenetic inferences in mammals are increasingly made with larger, even genomic scale datasets (e. g., Meredith et al. 2011; Foley et al. 2016). In this study we found the COI gene to be a useful marker for species identification; however, more taxa and loci are needed to obtain robust phylogenies of these rodent taxa.

Along the Andes there are three main patterns of allopatric distributions: (1) a latitudinal pattern is evidenced when a pair of sister species are distributed one to the north and the other to the south, e. g., Hippocamelus antisensis (north) vs. H. bisulcus (south), and Nasuella meridensis (north) vs. N. olivacea (south) (Helgen et al. 2009; Pinto et al. 2016); (2) a cross Andean pattern is evidenced when a pair of sister species are distributed with one in the eastern slopes and another in the western slopes of the Andes, e. g., Bassaricyon alleni (east) vs. B. medius (west) (Helgen et al. 2013); and (3) altitudinal pattern is evidenced when one species is in higher elevations and its close relatives are in lower elevations, e. g., Bassaricyon neblina and Dactylomys peruanus vs. the rest of the species in their respective genera (Helgen et al. 2013; Upham et al. 2013). In this work, we highlight further possible examples of the cross Andean pattern of distributions: of the three species supposedly shared between the eastern and western slopes of the Andes, two (Chilomys instans and Akodon mollis) may represent multiple species. However, suggestion of two species within Akodon mollis in particular should be interpreted with caution; the scant genetic differentiation between the Otonga and Sangay specimens (< 2 %) and the fact that A. mollis is a widespread Andean species might suggest that intermediate lineages in the inter-Andean valleys are yet to be found, and we may have only one — not multiple — species level clades (Lee et al. 2011). Further sampling, and the analysis of additional morphological and genetic data will elucidate whether A. mollis is one or multiple species (Alvarado-Serrano et al. 2013). Our results from DNA barcoding provide preliminary views into biodiversity within these lineages which can be explored with other datasets, approaches, and sampling.

As noted, our results indicate that the interpretations of rodent species being widely distributed across both the eastern and western slopes of the tropical Andes should be viewed with certain caution. Of the species that we sampled in our comparisons, only Microryzomys minutus can be considered to indeed occupy both Andean slopes in light of our barcode data. Potentially, this Andean species is well adapted to different environments such as high elevation grasslands (páramos), Andean forests, and inter-Andean valleys. This tolerance to multiple environments would facilitate the colonization of both Andean slopes, but at the same time this may suggest that forest specialists (e. g., Chilomys) would be less likely to colonize both Andean slopes.

Species delimitation methods, such as PTP and GMYC, are useful as an initial approach to delimit species using DNA sequences (Pons et al. 2006; Zhang et al. 2013). While these inferences are useful, there are also several pitfalls associated with these analyses and the results should be taken with caution, particularly when only one method and locus are used (Carstens et al. 2013). In our results, the splitting of Akodon mollis could very well represent a false positive associated with shallow genetic differentiation; however, the deep divergence between both clades within Chilomys instans indicates that the delimitation results might reflect real species-level diversity (Figure 2). In the case of species delimitation of the subfamily Sigmodontinae (Tree C), it is possible that there was an over-splitting of species by the PTP analysis; for example, there was a potential over splitting of Hylaeamys yunganus in multiple species (Figure 6). Further systematic research will clarify the species limits of these taxa.

Following the analyses of González-Ittig et al. (2014) we preliminarily recognize the Oligoryzomys of the western slopes of the Ecuadorian Andes as O. spodiurus; these populations were traditionally regarded as part of the widespread O. destructor (Weksler and Bonvicino 2015). We also recovered Oligoryzomys as paraphyletic, but we propose that this may be due to two artifacts: incorrect identifications of various voucher specimens associated with sequences available in GenBank (sequences of specimen MN71255 [GenBank accession number: KF815407] (Figure 4C) actually belongs to Necromys lasiurus, based on the analysis of CYTB of the same specimen,results not shown); and putative pseudogenes (Numts; Bensasson et al. 2001) in sequences generated by Müller et al. (2013) [GenBank accession numbers: GU938877, GU938878, GU938886-GU938890, GU938892-GU938894, GU938898, GU938899, GU938953, GU938969-GU938988] (Figure 4A), based on the position of these sequences in an analyses of a larger data- set of Oligoryzomys barcodes (M. Weksler et al., in prep.). Traditionally, the genus Oligorzomys has been a hard group to study because of the availability of a large number of taxonomic names and various difficulties inherent in assessing patterns of morphological variation. Fortunately, there have been new efforts to generate a more comprehensive understanding of the diversity in the genus (Weksler and Bonvicino 2005, 2015; González-Ittig et al. 2014; Weksler et al. 2017). Our barcode data corroborate the sister relationship of Oreoryzomys, a poorly studied Andean genus, and Microryzomys (Weksler 2006).

Even though our phylogenetic analysis of the COI gene did not recover the two species of Mindomys as monophyletic (Figure 5), further analysis with the IRBP and CYTB gene do indeed recover these two species as a monophyletic lineage (C. M. Pinto and M. Weksler in prep.), a good example of the marked limitation of DNA barcoding for providing accurate insight into species-level phylogenetics. Mindomys form a monophyletic group with Nephelomys; both of these genera are mostly Andean, with two species of Nephelomys, N. devius and N. pirrensis, distributed in the mountain areas of Central America (Percequillo 2003, 2015). Our barcode data suggest that N. moerex of the western slopes of the Andes may be most closely related to Central American species (Figure 5). Without further systematic study we are not yet confident in assigning species names to the two candidate species of the eastern slopes of the Andes; potential names for these candidate species include N. albigularis, N. auriventer, and N. nimbosus (Brito et al. 2015; Percequillo 2015; Tinoco López 2015).

The tribe Thomasomyini was not recovered as monophyletic in our Maximum Likelihood analyses (Figure 2). This result is not surprising for several reasons: 1) Monophyly of this tribe is not strongly supported in studies using additional molecular data — CYTB and IRBP genes — (Salazar-Bravo et al. 2016). 2) The COI marker is problematic for unveiling deep nodes in phylogenies; a recent example of this limitation is the utility of this marker to in the phylogeny of bats, without using constraints (Amador et al. in press). 3) The taxonomic sampling of the analysis was very limited with only 24 species; it is known that phylogenetic accuracy increases with taxon sampling (Zwickl and Hillis 2002).

Currently, specimens of Thomasomys from Sangay are assigned to T. caudivarius, T. cinnameus, T. paramorum, T. princeps and T. taczanowskii (Lee et al. 2011, 2015). Our phylogenetic analyses show that true T. silvestris, from Otonga, are sister to a clade formed by T. paramorum and T. cinnameus; also the large species T. princeps is closely related to small sized species T. baeops and T. taczanowskii. These relationships differ from previous phylogenetic hypotheses based solely on morphological or CYTB data (Pacheco 2003; Lee et al. 2011, 2015); the single relationship that is constant across phylogenies is the sister relationship of T. baeops and T. taczanowskii. Two putative species were recovered within T. taczanowskii (Figure 2); however, it is possible that they correspond to a single species given the scant genetic divergence with the COI gene (3 %). The puzzling pattern showing that large species of Thomasomys do not form a clade (Lee et al. 2015) potentially indicates multiple origins of the large body-size phenotype, suggesting that the evolution of body size in Thomasomys is more complex than previously suggested by discrete grouping of species by body-size (Pacheco 2003, 2015). Detailed exploration of the radiation of thomasomyine rodents along the Andes is much needed, and will likely provide exciting results about diversification patterns along the Andes, as have emerged from studies of plants (e. g., Monasterio and Sarmiento 1991; Hughes and Eastwood 2006; Nürk et al. 2013).

The results for Echimyidae show that the analyzed sequences of Mesomys hispidus contain two putative species with divergences in the range of 6.9- 7.2 % (Figure 3). One of these putative species is distributed in the Guiana Shield, and the other in the western Amazon of Ecuador. These results are in line with the findings of five relatively deep mitochondrial clades within M. hispidus, with mean divergence 4.6 % (Patton et al. 1994, 2000). Also, our results suggest that the Mesomys sample (JBM 368) from the Andes is conspecific with the Mesomys from Yasuní in the western Amazonian lowlands (genetic divergence ranging from 1.2 to 1.4 %). These results contrast with a previous analysis, in which the sample JBM 368 was assigned as a different species from the lowland samples (Upham et al. 2013). Additional work on the morphology and genetics of M. hispidus will be needed to clarify its taxonomy.

Our results indicate that the alpha taxonomy of the tropical Andean rodents is still not fully resolved, for example with respect to delineation of species in the genera Chilomys and Mindomys. Also, COI sequences that we have obtained for the genera Thomasomys and Chilomys provide the first data from this marker for these genera, and may be useful for onward rodent barcoding efforts and for efforts toward a comprehensive multilocus phylogeny of thomasomyines, which remains an outstanding goal in Neotropical mammalogy (Salazar-Bravo and Yates 2007; Lee et al. 2011, 2015). While acknowledging its limitations, we encourage research teams studying Neotropical rodents to provide DNA barcoding data whenever possible, which may help to speed new species discoveries and taxonomic reviews in a highly diverse order in which many lines of basic taxonomic and inventory research remain open, active, and fruitful.


Fieldwork discussed in our paper was facilitated by a grant from the Texas Tech University Association of Biologists to CMP, a Fulbright United States Student Program grant and a Barbara E. Brown Fund for Mammal Research (FMNH) to RO-B, and grants and funds of Abilene Christian University to TEL. The Sackler Institute for Comparative Genomics at the American Museum of Natural History, and the Smithsonian Institution funded laboratory work. Escuela Politécnica Nacional supported CMP through grants PIMI-14-10 and PII-ICB-03-2017. We thank Roland Kays, Paul Pinto, Elicio Tapia, and Don Wilson for help in the field. We thank Verónica Crespo-Pérez for a helpful revision of this manuscript and providing help with figures. Katherine Moreno helped with the map, and Pablo Moreno helped locating specimens and data. Field expeditions were conducted under legal authorizations of the Ministerio del Ambiente de la República del Ecuador; permit numbers: 020 IC FAU-DNBAPVS/MA, 02-2010-FAU-DPAP-MA, 001-12-PMVS-FAU-DNB/MA,13-2011-INVESTIGACION-B- DPMS/MAE, and MAE-DNA-CM-2015-0029.

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Associated editor: Guillermo D´Elia


List of the 201 samples of mammals from Otonga Reserve and Sangay National Park sequenced for this study. List includes collector numbers, museum numbers, collection locality, and GenBank accession numbers. 

Species Field number Tissue number Museum number Locality GenBank Accession
Akodon mollis A PS14 -- FMNH 219797 Sangay MF806219
Akodon mollis A PS4 -- FMNH 219798 Sangay MF806236
Akodon mollis A PS17 -- FMNH 219804 Sangay MF806257
Akodon mollis A PS26 -- FMNH 219805 Sangay MF806260
Akodon mollis A PS6 -- MEPN 12135 Sangay MF806212
Akodon mollis A PS10 -- MEPN 12138 Sangay MF806220
Akodon mollis A PS34 -- MEPN 12156 Sangay MF806223
Akodon mollis A PS39 -- MEPN 12161 Sangay MF806238
Akodon mollis A TEL2235 ACUNHC1618 QCAZ 11880 Sangay MF806242
Akodon mollis A TEL2242 -- QCAZ 11881 Sangay MF806261
Akodon mollis A TEL2256 ACUNHC1595 QCAZ 11882 Sangay MF806234
Akodon mollis A TEL2257 ACUNHC1586 QCAZ 11883 Sangay MF806226
Akodon mollis A TEL2321 ACUNHC1583 QCAZ 11884 Sangay MF806254
Akodon mollis A TEL2328 ACUNHC1585 QCAZ 11885 Sangay MF806256
Akodon mollis A TEL2346 -- QCAZ 11888 Sangay MF806252
Akodon mollis A TEL2363 -- QCAZ 11889 Sangay MF806240
Akodon mollis A TEL2237 ACUNHC1587 QCAZ 11890 Sangay MF806245
Akodon mollis A TEL2238 ACUNHC1575 QCAZ 11891 Sangay MF806239
Akodon mollis A TEL2240 ACUNHC1620 QCAZ 11892 Sangay MF806248
Akodon mollis A TEL2253 ACUNHC1619 QCAZ 11893 Sangay MF806224
Akodon mollis A TEL2259 -- QCAZ 11894 Sangay MF806225
Akodon mollis A TEL2268 -- QCAZ 11895 Sangay MF806216
Akodon mollis A TEL2269 ACUNHC1603 QCAZ 11896 Sangay MF806235
Akodon mollis A TEL2272 ACUNHC1616 QCAZ 11897 Sangay MF806221
Akodon mollis A TEL2273 ACUNHC1604 QCAZ 11898 Sangay MF806217
Akodon mollis A TEL2276 ACUNHC1628 QCAZ 11899 Sangay MF806262
Akodon mollis A TEL2277 ACUNHC1577 QCAZ 11900 Sangay MF806258
Akodon mollis A TEL2280 ACUNHC1579 QCAZ 11901 Sangay MF806222
Akodon mollis A TEL2281 -- QCAZ 11902 Sangay MF806218
Akodon mollis A TEL2282 ACUNHC1584 QCAZ 11903 Sangay MF806237
Akodon mollis A TEL2286 -- QCAZ 11904 Sangay MF806249
Akodon mollis A TEL2289 -- QCAZ 11905 Sangay MF806263
Akodon mollis A TEL2297 ACUNHC1591 QCAZ 11906 Sangay MF806227
Akodon mollis A TEL2299 -- QCAZ 11907 Sangay MF806255
Akodon mollis A TEL2302 -- QCAZ 11908 Sangay MF806228
Akodon mollis A TEL2314 ACUNHC1576 QCAZ 11910 Sangay MF806229
Akodon mollis A TEL2317 ACUNHC1596 QCAZ 11911 Sangay MF806230
Akodon mollis A TEL2350 -- QCAZ 11913 Sangay MF806259
Akodon mollis A TEL2352 -- QCAZ 11914 Sangay MF806253
Akodon mollis A TEL2356 -- QCAZ 11915 Sangay MF806243
Akodon mollis A TEL2370 ACUNHC1581 QCAZ 11916 Sangay MF806250
Akodon mollis A TEL2376 -- QCAZ 11917 Sangay MF806241
Akodon mollis A TEL2379 -- QCAZ 11918 Sangay MF806246
Akodon mollis A TEL2385 -- QCAZ 11919 Sangay MF806244
Akodon mollis A TEL2389 ACUNHC1580 QCAZ 11920 Sangay MF806247
Akodon mollis A TEL2390 -- QCAZ 11921 Sangay MF806214
Akodon mollis A TEL2391 -- QCAZ 11922 Sangay MF806231
Akodon mollis A TEL2392 -- QCAZ 11923 Sangay MF806213
Akodon mollis A TEL2396 -- QCAZ 11924 Sangay MF806232
Akodon mollis A TEL2397 -- QCAZ 11925 Sangay MF806215
Akodon mollis A TEL2399 -- QCAZ 11926 Sangay MF806211
Akodon mollis A TEL2400 -- QCAZ 11927 Sangay MF806251
Akodon mollis A TEL2401 -- QCAZ 11928 Sangay MF806233
Akodon mollis B KMH2227 TK149044 QCAZ 8634 Otonga MF806209
Akodon mollis B MP74 TK149070 QCAZ 8635 Otonga MF806210
Chilomys instans A PS24 -- MEPN 12149 Sangay MF806264
Chilomys instans B MP62 TK149051 QCAZ 8691 Otonga MF806266
Chilomys instans B MP64 TK149053 QCAZ 8693 Otonga MF806269
Chilomys instans B MP69 TK149058 QCAZ 8694 Otonga MF806265
Chilomys instans B MP91 TK149099 QCAZ 8695 Otonga MF806267
Chilomys instans B KMH2241 TK149080 QCAZ 8740 Otonga MF806268
Hylaeamys tatei PS22 -- MEPN 12147 Sangay MF806196
Mesomys hispidus JBM368 -- MEPN 12212 Kutukú MF806172
Microryzomys altissimus TEL2298 -- QCAZ 11929 Sangay MF806185
Microryzomys altissimus TEL2347 ACUNHC1553 QCAZ 11930 Sangay MF806183
Microryzomys altissimus TEL2278 ACUNHC1605 QCAZ 11931 Sangay MF806182
Microryzomys altissimus TEL2279 -- QCAZ 11932 Sangay MF806179
Microryzomys altissimus TEL2322 -- QCAZ 11933 Sangay MF806181
Microryzomys altissimus TEL2327 -- QCAZ 11934 Sangay MF806180
Microryzomys altissimus TEL2258 -- QCAZ 11973 Sangay MF806184
Microryzomys altissimus KMH2235 TK149063 QCAZ 8673 Otonga MF806186
Microryzomys minutus KMH2236 TK149064 QCAZ 8674 Otonga MF806187
Microryzomys minutus KMH2257 TK149106 QCAZ 8675 Otonga MF806189
Microryzomys minutus KMH2258 TK149107 QCAZ 8676 Otonga MF806188
Microryzomys minutus MP53 TK149026 QCAZ 8677 Otonga MF806195
Microryzomys minutus PS9 -- FMNH 219796 Sangay MF806194
Microryzomys minutus PS35 -- MEPN 12158 Sangay MF806191
Microryzomys minutus PS69 -- MEPN 12190 Sangay MF806190
Microryzomys minutus TEL2362 ACUNHC1556 QCAZ 11935 Sangay MF806193
Microryzomys minutus TEL2371 ACUNHC1571 QCAZ 11936 Sangay MF806192
Mindomys sp. MP88 TK149096 QCAZ 8720 Otonga MF806197
Nephelomys moerex KMH2204 TK149005 QCAZ 8696 Otonga MF806204
Nephelomys moerex KMH2210 TK149009 QCAZ 8697 Otonga MF806198
Nephelomys moerex KMH2221 TK149038 QCAZ 8700 Otonga MF806201
Nephelomys moerex KMH2253 TK149102 QCAZ 8709 Otonga MF806202
Nephelomys moerex MP83 TK149079 QCAZ 8717 Otonga MF806203
Nephelomys moerex MP90 TK149098 QCAZ 8718 Otonga MF806200
Nephelomys moerex MP93 TK149101 QCAZ 8719 Otonga MF806199
Nephelomys sp. A PS2 -- FMNH 219795 Sangay MF806205
Nephelomys sp. B PS3 -- MEPN 12133 Sangay MF806206
Oligoryzomys spodiurus MP75 TK149071 QCAZ 8678 Otonga MF806174
Oligoryzomys spodiurus MP85 TK149093 QCAZ 8681 Otonga MF806173
Oreoryzomys balneator -- -- MEPN 12226 Cordillera del Cóndor MF806175
Oreoryzomys balneator PS66 -- MEPN 12187 Sangay MF806178
Oreoryzomys balneator PS57 -- MEPN 12189 Sangay MF806177
Oreoryzomys balneator PS56 -- MEPN 12197 Sangay MF806176
Rhipidomys albujai PS75 -- MEPN 12196 Sangay MF806208
Rhipidomys sp. -- -- MEPN 12114 Cordillera del Cóndor MF806207
Thomasomys baeops MP92 TK149100 QCAZ 8746 Otonga MF806276
Thomasomys baeops KMH2225 TK149042 QCAZ 8692 Otonga MF806275
Thomasomys baeops KMH2209 TK149010 QCAZ 8739 Otonga MF806274
Thomasomys caudivarius PS28 -- MEPN 12151 Sangay MF806307
Thomasomys caudivarius PS29 -- MEPN 12152 Sangay MF806323
Thomasomys caudivarius PS36 -- MEPN 12159 Sangay MF806309
Thomasomys caudivarius TEL2345 ACUNHC1602 QCAZ 11912 Sangay MF806325
Thomasomys caudivarius TEL2270 ACUNHC1572 QCAZ 11949 Sangay MF806310
Thomasomys caudivarius TEL2271 ACUNHC1592 QCAZ 11950 Sangay MF806312
Thomasomys caudivarius TEL2285 ACUNHC1563 QCAZ 11951 Sangay MF806313
Thomasomys caudivarius TEL2287 -- QCAZ 11952 Sangay MF806314
Thomasomys caudivarius TEL2293 ACUNHC1557 QCAZ 11953 Sangay MF806322
Thomasomys caudivarius TEL2301 ACUNHC1562 QCAZ 11954 Sangay MF806315
Thomasomys caudivarius TEL2318 -- QCAZ 11955 Sangay MF806311
Thomasomys caudivarius TEL2319 -- QCAZ 11956 Sangay MF806316
Thomasomys caudivarius TEL2343 ACUNHC1567 QCAZ 11959 Sangay MF806324
Thomasomys caudivarius TEL2344 -- QCAZ 11960 Sangay MF806308
Thomasomys caudivarius TEL2354 ACUNHC1554 QCAZ 11961 Sangay MF806321
Thomasomys caudivarius TEL2355 ACUNHC1573 QCAZ 11962 Sangay MF806317
Thomasomys caudivarius TEL2377 -- QCAZ 11964 Sangay MF806320
Thomasomys caudivarius TEL2393 -- QCAZ 11965 Sangay MF806326
Thomasomys caudivarius TEL2398 -- QCAZ 11966 Sangay MF806319
Thomasomys caudivarius TEL2402 -- QCAZ 11967 Sangay MF806318
Thomasomys cinnameus PS40 -- MEPN 12163 Sangay MF806291
Thomasomys cinnameus TEL2236 ACUNHC1601 QCAZ 11968 Sangay MF806299
Thomasomys cinnameus TEL2243 ACUNHC1564 QCAZ 11969 Sangay MF806293
Thomasomys cinnameus TEL2246 -- QCAZ 11970 Sangay MF806298
Thomasomys cinnameus TEL2250 -- QCAZ 11971 Sangay MF806297
Thomasomys cinnameus TEL2252 -- QCAZ 11972 Sangay MF806292
Thomasomys cinnameus TEL2291 ACUNHC1559 QCAZ 11975 Sangay MF806303
Thomasomys cinnameus TEL2292 ACUNHC1627 QCAZ 11976 Sangay MF806300
Thomasomys cinnameus TEL2296 ACUNHC1610 QCAZ 11977 Sangay MF806301
Thomasomys cinnameus TEL2307 ACUNHC1611 QCAZ 11978 Sangay MF806295
Thomasomys cinnameus TEL2308 -- QCAZ 11979 Sangay MF806294
Thomasomys cinnameus TEL2310 ACUNHC1582 QCAZ 11980 Sangay MF806305
Thomasomys cinnameus TEL2311 -- QCAZ 11981 Sangay MF806302
Thomasomys cinnameus TEL2329 -- QCAZ 11982 Sangay MF806306
Thomasomys cinnameus TEL2274 -- QCAZ 11983 Sangay MF806296
Thomasomys cinnameus TEL2365 -- QCAZ 12018 Sangay MF806337
Thomasomys paramorum TEL2233 ACUNHC1624 QCAZ 11984 Sangay MF806359
Thomasomys paramorum TEL2234 ACUNHC1593 QCAZ 11985 Sangay MF806360
Thomasomys paramorum TEL2239 ACUNHC1626 QCAZ 11986 Sangay MF806361
Thomasomys paramorum TEL2241 ACUNHC1590 QCAZ 11987 Sangay MF806362
Thomasomys paramorum TEL2244 ACUNHC1600 QCAZ 11988 Sangay MF806358
Thomasomys paramorum TEL2245 ACUNHC1625 QCAZ 11989 Sangay MF806357
Thomasomys paramorum TEL2247 ACUNHC1597 QCAZ 11990 Sangay MF806329
Thomasomys paramorum TEL2248 ACUNHC1574 QCAZ 11991 Sangay MF806363
Thomasomys paramorum TEL2249 ACUNHC1607 QCAZ 11992 Sangay MF806364
Thomasomys paramorum TEL2251 ACUNHC1589 QCAZ 11993 Sangay MF806356
Thomasomys paramorum TEL2255 ACUNHC1612 QCAZ 11994 Sangay MF806334
Thomasomys paramorum TEL2262 ACUNHC1599 QCAZ 11996 Sangay MF806333
Thomasomys paramorum TEL2263 ACUNHC1606 QCAZ 11997 Sangay MF806354
Thomasomys paramorum TEL2264 ACUNHC1608 QCAZ 11998 Sangay MF806353
Thomasomys paramorum TEL2300 ACUNHC1615 QCAZ 11999 Sangay MF806352
Thomasomys paramorum TEL2309 ACUNHC1569 QCAZ 12000 Sangay MF806340
Thomasomys paramorum TEL2312 ACUNHC1622 QCAZ 12001 Sangay MF806327
Thomasomys paramorum TEL2320 -- QCAZ 12002 Sangay MF806355
Thomasomys paramorum TEL2323 ACUNHC1568 QCAZ 12003 Sangay MF806335
Thomasomys paramorum TEL2324 -- QCAZ 12004 Sangay MF806330
Thomasomys paramorum TEL2325 ACUNHC1613 QCAZ 12005 Sangay MF806304
Thomasomys paramorum TEL2326 -- QCAZ 12006 Sangay MF806341
Thomasomys paramorum TEL2348 -- QCAZ 12011 Sangay MF806338
Thomasomys paramorum TEL2349 ACUNHC1558 QCAZ 12012 Sangay MF806346
Thomasomys paramorum TEL2351 -- QCAZ 12013 Sangay MF806336
Thomasomys paramorum TEL2353 -- QCAZ 12014 Sangay MF806344
Thomasomys paramorum TEL2357 -- QCAZ 12015 Sangay MF806339
Thomasomys paramorum TEL2358 -- QCAZ 12016 Sangay MF806342
Thomasomys paramorum TEL2364 -- QCAZ 12017 Sangay MF806331
Thomasomys paramorum TEL2366 -- QCAZ 12019 Sangay MF806347
Thomasomys paramorum TEL2367 -- QCAZ 12020 Sangay MF806343
Thomasomys paramorum TEL2368 -- QCAZ 12021 Sangay MF806366
Thomasomys paramorum TEL2369 -- QCAZ 12022 Sangay MF806349
Thomasomys paramorum TEL2374 -- QCAZ 12023 Sangay MF806332
Thomasomys paramorum TEL2375 -- QCAZ 12024 Sangay MF806348
Thomasomys paramorum TEL2380 ACUNHC1549 QCAZ 12025 Sangay MF806365
Thomasomys paramorum TEL2381 -- QCAZ 12026 Sangay MF806345
Thomasomys paramorum TEL2383 -- QCAZ 12027 Sangay MF806351
Thomasomys paramorum TEL2384 -- QCAZ 12028 Sangay MF806350
Thomasomys paramorum TEL2275 ACUNHC1623 QCAZ 12029 Sangay MF806328
Thomasomys princeps TEL2288 -- QCAZ 11937 Sangay MF806271
Thomasomys princeps TEL2295 -- QCAZ 11938 Sangay MF806273
Thomasomys princeps TEL2378 ACUNHC1560 QCAZ 11939 Sangay MF806272
Thomasomys princeps TEL2394 ACUNHC1548 QCAZ 11940 Sangay MF806270
Thomasomys silvestris KMH2237 TK149065 QCAZ 8741 Otonga MF806371
Thomasomys silvestris MP66 TK149055 QCAZ 8742 Otonga MF806367
Thomasomys silvestris MP68 TK149057 QCAZ 8743 Otonga MF806369
Thomasomys silvestris MP70 TK149059 QCAZ 8744 Otonga MF806372
Thomasomys silvestris KMH2231 TK149048 QCAZ 8747 Otonga MF806370
Thomasomys silvestris MP82 TK149078 QCAZ 8749 Otonga MF806368
Thomasomys taczanowskii A PS56 -- FMNH 219801 Sangay MF806277
Thomasomys taczanowskii A PS25 -- FMNH 219803 Sangay MF806278
Thomasomys taczanowskii B -- -- MEPN 12224 Cordillera del Cóndor MF806282
Thomasomys taczanowskii B PS1 -- MEPN 12132 Sangay MF806285
Thomasomys taczanowskii B PS64 -- MEPN 12185 Sangay MF806281
Thomasomys taczanowskii B TEL2254 ACUNHC1598 QCAZ 11941 Sangay MF806286
Thomasomys taczanowskii B TEL2290 ACUNHC1570 QCAZ 11942 Sangay MF806287
Thomasomys taczanowskii B TEL2306 ACUNHC1614 QCAZ 11943 Sangay MF806288
Thomasomys taczanowskii B TEL2386 -- QCAZ 11945 Sangay MF806290
Thomasomys taczanowskii B TEL2387 -- QCAZ 11946 Sangay MF806289
Thomasomys taczanowskii B TEL2388 -- QCAZ 11947 Sangay MF806280
Thomasomys taczanowskii B TEL2395 -- QCAZ 11948 Sangay MF806279
Thomasomys taczanowskii B TEL2372 -- QCAZ 11963 Sangay MF806283
Thomasomys taczanowskii B TEL2261 ACUNHC1609 QCAZ 11995 Sangay MF806284

Received: July 15, 2016; Accepted: September 13, 2017

* Corresponding author: C. Miguel Pinto, e-mail:

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