\documentclass[10pt]{article}

\usepackage{fullpage}
\usepackage{setspace}
\usepackage{parskip}
\usepackage{titlesec}
\usepackage[section]{placeins}
\usepackage{xcolor}
\usepackage{breakcites}
\usepackage{lineno}
\usepackage{hyphenat}





\PassOptionsToPackage{hyphens}{url}
\usepackage[colorlinks = true,
            linkcolor = blue,
            urlcolor  = blue,
            citecolor = blue,
            anchorcolor = blue]{hyperref}
\usepackage{etoolbox}
\makeatletter
\patchcmd\@combinedblfloats{\box\@outputbox}{\unvbox\@outputbox}{}{%
  \errmessage{\noexpand\@combinedblfloats could not be patched}%
}%
\makeatother


\usepackage{natbib}




\renewenvironment{abstract}
  {{\bfseries\noindent{\abstractname}\par\nobreak}\footnotesize}
  {\bigskip}

\titlespacing{\section}{0pt}{*3}{*1}
\titlespacing{\subsection}{0pt}{*2}{*0.5}
\titlespacing{\subsubsection}{0pt}{*1.5}{0pt}


\usepackage{authblk}


\usepackage{graphicx}
\usepackage[space]{grffile}
\usepackage{latexsym}
\usepackage{textcomp}
\usepackage{longtable}
\usepackage{tabulary}
\usepackage{booktabs,array,multirow}
\usepackage{amsfonts,amsmath,amssymb}
\providecommand\citet{\cite}
\providecommand\citep{\cite}
\providecommand\citealt{\cite}
% You can conditionalize code for latexml or normal latex using this.
\newif\iflatexml\latexmlfalse
\providecommand{\tightlist}{\setlength{\itemsep}{0pt}\setlength{\parskip}{0pt}}%

\AtBeginDocument{\DeclareGraphicsExtensions{.pdf,.PDF,.eps,.EPS,.png,.PNG,.tif,.TIF,.jpg,.JPG,.jpeg,.JPEG}}

\usepackage[utf8]{inputenc}
\usepackage[T2A]{fontenc}
\usepackage[ngerman,polish,english]{babel}



\usepackage{float}








\begin{document}

\title{Undervalued habitat or impoverished guild? Exploring the scarcity of
living semiaquatic sigmodontine rodents}



\author[1]{Ulyses Pardiñas}%
\author[2]{Erika Cuellar Soto}%
\affil[1]{CONICET}%
\affil[2]{Sultan Qaboos University}%


\vspace{-1em}



  
  \date{May 21, 2024}


\begingroup
\let\center\flushleft
\let\endcenter\endflushleft
\maketitle
\endgroup





\selectlanguage{english}
\begin{abstract}
Sigmodontines (Rodentia: Cricetidae), the largest living radiation of
Neotropical rodents (90 genera, 489 species), show about 10\% having
specializations related to a semiaquatic habitat. In addition, this mode
of life is unequally distributed among the several clades which compose
the subfamily, concentrated in the Ichthyomyini and in a few
large-bodied Oryzomyini. The observed taxonomical and geographical
pattern is here discussed in a biogeographical historical context. As
working hypothesis is advanced that the risk of predation (exerted by
animalivorous fresh-water vertebrates) shaped and limited since the late
Miocene the semiaquatic performance of the subfamily. Moreover, by
exploring the fossil record can also be argued that during the
Pleistocene is registered an important number of amphibious
sigmodontines extinctions. Therefore, the scarcity of living semiaquatic
sigmodontine rodents can be attributed to a combination of an
undervalued habitat (mostly by risk of predation) plus a recent
pauperization (by a sum of biological extinctions) of the members of
that guild. A shallow comparison of the sigmodontine case against murids
suggests that continental waterbodies resulted partially refractory to
muroid colonizations.%
\end{abstract}%



\sloppy


Undervalued habitat or impoverished guild? Exploring the scarcity of
living semiaquatic sigmodontine rodents

Ulyses F. J. Pardi\selectlanguage{ngerman}ñas\textsuperscript{1*} and Erika Cuéllar
Soto\textsuperscript{2}

\textsuperscript{1}Instituto de Diversidad y Evolución Austral
(IDEAus-CONICET), CONICET, Puerto Madryn, Chubut, Argentina \& Instituto
Nacional de Biodiversidad (INABIO), Quito, Pichincha, Ecuador.
https://orcid.org/0000-0001-9496-5433.

\textsuperscript{2}Department of Biology, College of Science, Sultan
Qaboos University, Muscat, Oman. https://orcid.org/0000-0003-2271-8956.

*Corresponding author: Ulyses F. J. Pardiñas,
ulyses@cenpat-conicet.gob.ar

Abstract. Sigmodontines (Rodentia: Cricetidae), the largest living
radiation of Neotropical rodents (90 genera, 489 species), show about
10\% having specializations related to a semiaquatic habitat. In
addition, this mode of life is unequally distributed among the several
clades which compose the subfamily, concentrated in the Ichthyomyini and
in a few large-bodied Oryzomyini. The observed taxonomical and
geographical pattern is here discussed in a biogeographical historical
context. As working hypothesis is advanced that the risk of predation
(exerted by animalivorous fresh-water vertebrates) shaped and limited
since the late Miocene the semiaquatic performance of the subfamily.
Moreover, by exploring the fossil record can also be argued that during
the Pleistocene is registered an important number of amphibious
sigmodontines extinctions. Therefore, the scarcity of living semiaquatic
sigmodontine rodents can be attributed to a combination of an
undervalued habitat (mostly by risk of predation) plus a recent
pauperization (by a sum of biological extinctions) of the members of
that guild. A shallow comparison of the sigmodontine case against murids
suggests that continental waterbodies resulted partially refractory to
muroid colonizations.

Key words: Cricetidae, Ichthyomyini, Oryzomyini, South America, Miocene,
Predation.

Puerto Madryn, July 15, 2023

Editors-in-Chief

Chris Foote, John Wiley \& Sons, UK, cfoote@wiley.com

Dear Dr Foote,

Please find enclosed the manuscript entitled ``Undervalued habitat or
impoverished guild? Exploring the scarcity of living semiaquatic
sigmodontine rodents'' (authors: Pardiñas and Cuellar). It has been
submitted to your journal for consideration in the category ``Nature
Notes.''

This paper gives a supported investigation into why a successful rodent
radiation, the sigmodontines (the biggest Neotropical diversification of
terrestrial mammals), failed to provide an appropriate performance
colonizing fresh-water habitats.

Thank you in advance for your time and help. Kind regards,\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/image1/image1}

\end{center}
\end{figure}

Ulyses Pardi\selectlanguage{ngerman}ñas

Corresponding author

ulyses@cenpat-conicet.gob.ar

Neotropics contain four of the largest river basins of the Earth
(Amazonas, Orinoco, La Plata and São Francisco), covering about
two-thirds of the continent (Ayres \& Clutton-Brock, 1992). The most
impressive and famous, the Amazon River drains about 7,050,000
km\textsuperscript{2} (out of the 17,840,000 in the continent) and has
more than 1,000 tributaries (Knapp et al., 2021). If there also
considered two of the largest wetlands of the world, the Pantanal and
Iberá-Ñeembucú (Junk, 2013), the entire region can be categorized as
plenty of surface freshwater (Hurlbert et al., 1981; Clapperton, 1993).
In sharp contrast with the latter, sigmodontines (Cricetidae:
Sigmodontinae), the most speciose and widely distributed group of
rodents shows about 10\% of its diversity specialized (i.e. with
amphibious adaptations) to exploit this kind of habitats (Pardiñas et
al., 2017). The intriguing aspect is why this noticeable mammal
radiation has such a modest performance in semi aquatic environments?
The present note aims to discuss whether sigmodontine colonization of
fresh water reflects undervaluation (i.e., the group, for any reason,
failed to exploit extensively the habitat), pauperization (i.e., during
the past, the group had a greater amphibious diversity today
extinguished), or a combination of both.

Two recent compilations (Patton et al., 2005; Pardiñas et al., 2017)
containing an exhaustive list of sigmodontine rodents were used as basic
data (Appendix 1). Each species was typified as semiaquatic or
non-semiaquatic according to a combination of external morphological
traits and natural history data. Semiaquatic forms are those showing at
least two of the following features (listed in alphabetical order): 1)
body pelage composed by two layers, including a wooly underfur and a
superficial overfur; 2) continuous comb of stiff hairs along the
metatarsal margins and between the digits fringing the sole of the pes;
3) midventral hairs conspicuously longer than hairs on the dorsal and
lateral surfaces of the tail; 4) moderately-developed webbing between
digits II, III, and IV of the manus; 5) mystacial vibrissae highly
developed, numerous, and stiff; 6) nostrils high in the snout,
anterolaterally placed and posteriorly enlarged by a small diverticulum
flanked by a developed ala nasi ventralis; 7) noticeable small
interdigital and metacarpal pedal pads; 8) prismatic cross-section of
basal tail; and 9) well-developed interdigital webbing between pedal
digits II, III, and IV. The selected external features have been
highlighted as indicative of adaptation to aquatic habitats in
sigmodontines and other muroids reflecting important activities
developed into fresh-water bodies (rivers, streams, lakes, marshes) such
as dispersal, foraging, nesting, and reproduction (e.g., Hershkovitz,
1966, 1969; Pine et al., 1981, Voss, 1988; Sierra de Soriano, 1965,
1969; Starrett \& Fisler, 1970; Massoia, 1976; Miller \& Anderson, 1977;
Esher et al., 1978; Kerbis Peterhans \& Patterson, 1995; Weksler, 2006;
Santori et al., 2008, Rowe et al., 2014).

The analyzed data demonstrates that only a few sigmodontines can be
considered as semiaquatic (Appendix 1), according to the following
detail: 1) all the recognized Ichthyomyini (20 species in 6 genera); 2)
a few members of Oryzomyini (15 species belonging to the
genera\emph{Amphinectomys} {[}1 sp.{]}, \emph{Holochilus}
{[}7{]},\emph{Lundomys} {[}1{]}, and \emph{Nectomys} {[}6{]}). Other 5
genera, including 3 oryzomyines (i.e., \emph{Oryzomys} ,
\emph{Pseudoryzomys} and\emph{Sigmodontomys} ) and 2 akodontines (i.e.,
\emph{Gyldenstolpia} and\emph{Scapteromys} ) have been associated to
aquatic habitats (e.g., Hershkovitz, 1966; Ávila-Pires, 1972; Massoia,
1976; Esher et al., 1978; Voss and Myers, 1991; Voss and Carleton, 1993;
Pardiñas et al., 2009). However, available data on natural history and
morphology contradict the consideration of these forms as semiaquatic.
For instance,\emph{Scapteromys} spp. is a well-studied case exemplifying
rats with remarkable swimming abilities but spending their vital time in
riverine habitats including the construction of galleries, nesting on
dry ground, and climbing activities (e.g., Massoia and Fornes 1964,
Hershkovitz 1966, Barlow 1969). \emph{Oryzomys palustris} has also
demonstrated capacities to face aquatic activities but not so deep
morphological adaptations (e.g., Esher et al., 1978; Weksler, 2006).
Overall, these sigmodontines are considered here as representing the
guild of ``waders'' according to the definitions provided by Kerbis
Peterhans and Patterson (1995: 346); ``waders'' combine adaptations to
live in periodically flooding environments. Although tenuously reputed
as semiaquatic (e.g., Pearson, 1951; Hershkovitz, 1970; Bianchini \&
Delupi, 1993), \emph{Mindomys} (Oryzomyini) and
\emph{Neotomys}(Euneomyini) can be discarded as integrating any of the
previous categories advanced (see Pardiñas et al. 2015, Brito et al.
2021). Summarizing, semiaquatic mode of life was adopted by 7\% and 11\%
of the living species (n=489) and genera (n=90), respectively, while
representing ``waders'' are 6\% and 3\%, respectively (Appendix 1). To
conclude that it corresponds to a little fraction of the subfamily
diversity is straightforward. However, the topic has also an
asymmetrical geographic component rather than strictly quantitative.
First, most of the ichthyomyine diversity is associated with streams and
rivers of Andean and mountain regions in northwestern South and Middle
America (Voss 1988, 2015a). Second, vast portions of tropical,
subtropical, and temperate South American eastern lowland rivers and
wetlands are inhabited almost exclusively by a handful of oryzomyines,
mostly belonging to \emph{Holochilus} and \emph{Nectomys} (e.g.,
Hershkovitz, 1955; Bonvicino and Weksler, 2015; Chiquito, 2015; Prado et
al., 2021). Finally, the southern portion of the continent lacks any
representative of this mode of life, being the southernmost
expressions\emph{Holochilus brasiliensis} and the rare \emph{Holochilus
lagigliai}both reaching the northern limit of Patagonia (Formoso et al.
2010, Pardiñas et al. 2013; Figure 1).

It is well-known that small mammal adaptation to live in fresh water is
challenging due to several factors, including locomotion,
thermoregulation, feeding strategy, and risk predation (e.g., Fish 1992,
Voss 1988, Fish et al. 2002). In addition, focusing on semiaquatic
sigmodontines, some limitations are directly avoided by intrinsic
specializations. For example, heat loss is minimized through fur
insulation (Santori et al. 2008). In this context, ichthyomyines
encompass a variety of morphological features likely representing
extreme adaptations to dive, swim, and prey invertebrates in clear and
rapid waters (Starrett and Fisler 1970; Voss 1988; Salazar-Bravo et al.,
2023). But semiaquatic specializations are not restricted to this tribe
because oryzomyine genera connected to the exploitation of fresh waters
also bear noticeable traits (e.g. large interdigital webbing, pes
enlargement, laterally compressed large tails, dorsally flattened heads,
small ears, integumental folds to the close of the nostrils, wool-hairs
well developed, etc.; Hershkovitz 1955, Sierra de Soriano 1965, 1969,
Massoia 1976). The above demonstrates that both main clades with
sigmodontines, Oryzomyalia and Sigmodontalia have been capable to handle
the challenge imposed by continental waters. Why so few sigmodontines,
in a continent plenty of aquatic resources, adopted this mode of life?

Although the topic is controversial, apparently the history of the
sigmodontines started in northern South America through colonization
from Central and North America by the latest Miocene (Prevosti et al.
2021, Ronez et al. 2021b and the references cited therein, Candela et
al. 2023, Romano et al. 2023). A commonplace biological possibility is
that the semiaquatic niche was already occupied by other mammals when
sigmodontine radiation begun. This hypothesis (niche saturation; e.g.,
Northfield et al. 2010, Cassini 2020) directs the attention to mammal
groups previously established in South America and currently having
semiaquatic representatives such as marsupials and caviomorph rodents.
Among the former, the poverty of living forms allied to waters is
remarkable, being \emph{Chironectes} the sole exception (Pine et al.
1981, Stein and Patton 2008). Caviomorphs embrace a few but emblematic
amphibious taxa such as \emph{Hydrochoerus} and \emph{Myocastor} and
others that revealed noticeable dive abilities (\emph{Cuniculus} ; e.g.
Patton et al. 2015). More indeed, the paleontological record indicates a
Mio-Pleistocene blossom of potentially semiaquatic forms including
entire disappear families and subfamilies (e.g., Neoepiblemidae,
Potamarchinae; Vucetich et al. 2015, Kerber et al. 2016). However, seems
hard to surmise any kind of competition among these groups and ancient
sigmodontines, taking in mind the overwhelming body-size differences.

A second plausible explanation on the poverty of semiaquatic
sigmodontines is simply time. The temporal window of the first main
sigmodontine dichotomy (i.e., the separation between Oryzomyalia and
Sigmodontalia) is estimated from molecular-based phylogenies in about 8
MA (Parada et al. 2021). Although the oldest fossils are markedly
younger (about 5.7 MA; see Candela et al. 2023, Romano et al. 2023), we
can suspect a bias regarding the paleontological record from suitable
areas in northern South America (see Ronez et al. 2023 for a synthesis).
Was the evolutionary time insufficient to allow a more diverse
adaptation to the aquatic niche? This question has not an easy answer.
However, it can be partially falsified by the ichthyomyines. If an
entire clade had the time to evolve a definite array of semiaquatic
adaptations is hard to understand why this process was not more
widespread. However, even when Oryzomyini seems to be one of the first
tribes to split (around 6 MA according to Parada et al. 2021), the
subclade containing semiaquatic forms (clade D) emerges later
(Percequillo et al. 2021). This temporal contrast between the two main
groups of amphibious sigmodontines could be partially explanatory of the
also important differential specialization level showed by them. To
complicate the overall picture, evolutionary rates are supposed to be
faster among animalivorous than in herbivorous muroids (Maestri et al.
2017).

In a fruitful discussion about body size and aquatic environments, Wolff
and Guthrie (1985) selected the risk predation as a main worldwide
explanation of larger bodies characterizing semiaquatic mammals. In one
hand, predation can be posed as the limiting factor that shaped the
Sigmodontinae evolutionary quantitative performance in continental
waters. Although rarely documented, occasional ingestion by fishes of
sigmodontine individuals fallen to waters seems widespread (e.g., Mann
Fischer 1978, Pardiñas et al., 2004; Vitule et al. 2015). On the other
hand, fresh water Neotropical fish assemblages are noticeably rich (just
the Amazon basin embraces \textgreater{}3000 species described; Junk
2007) and include a large variety of voracious kinds capable to exercise
potential predatory control (e.g., several piranhas Serrasalmidae,
electric eel \emph{Electrophorus electricus} , etc.; Reis et al. 2016).
But waterbodies are not only plagued of predatory fishes since the guild
of animalivorous predators also embraces a large diversity of turtles,
caimans, snakes, and even mammals. Although still scarcely known, fossil
assemblages from Late Miocene-Pliocene deposits in northern South
America are eloquent about an important paleodiversity of predatory
fishes and reptiles (e.g., Carrillo-Briceño et al. 2019, Cadena et al.
2020).

There is enough evidence to advance a working hypothesis capable to
provide an explanation integrating several of the topics raised above.
By the late Miocene, paleogeographic reconstructions indicate a northern
South America plenty of salty and fresh waterbodies (e.g., Lundberg et
al. 1998, McDermott 2021 and the references cited therein) and this was
the physical territory faced by earliest sigmodontines (Ronez et al.
2021b). Lineages diversified in lowlands were limited to exploit
continental waters mostly by non-mammal predators including a large
variety of fishes and reptiles recorded as fossils (e.g.,
Sánchez-Villagra et al. 2010). An ancient clade that had the chance to
colonize the growing Andean ranges was capable to produce an entire
group (Ichthyomyini) devoted of shallow and clear rivers and streams
mostly free of predatory animals (Reis et al. 2016). At the same time
that ichthyomyines begun its noticeable radiation a few oryzomyine
lowland lineages started to occupy pounds and marshes with a
comparatively lower risk of predation. They evolved following a tendency
to increase body-size as a co-evolutionary response to avoid predation
and herbivorous specialization (Wolff and Guthrie 1985).

But there is another non-excluding and exciting possibility in order to
explain semiaquatic living sigmodontines scarcity: extinctions. The
paleontological record for the subfamily is still mostly conformed by
disperse pieces and is more than insufficient to obtain a pale vision of
their past. However, even biased to southern South America and,
therefore, scarcely representing tropical and subtropical past areas
(Pardiñas et al. 2003, Ronez et al. 2023), there are several indications
of a greater diversity of preterit semiaquatic forms. Since fossils are
not much than isolated molars and cranial fragments it is clear that
morphological similarities are the base of our conjectures about extinct
taxa connection with fresh waters.

Discarding \selectlanguage{english}+\emph{Megalomys} , a Caribbean oryzomyines extinguished in
historical times and dubiously associated to aquatic environments (see
Miljutin 2010 for a detailed analysis), at least other 6 fossil genera
deserve attention (Figure 2). \selectlanguage{english}+\emph{Reigomys primigenus} , originally
described as a species of \emph{Holochilus} (see Steppan 1996), is an
enigmatic oryzomyine from the Pleistocene deposits of Tarija basin,
Bolivia (Hoffstetter 1973, Pardinas and Barbiere 2018).
\selectlanguage{english}+\emph{Noronhomys vespuccii} , another large oryzomyine endemic of
Noronha Island (Brazil) was described as a Quaternary form allied also
to \emph{Holochilus} (Carleton and Olson 1999). \selectlanguage{english}+\emph{Carletonomys
cailoi} , a giant oryzomyine from Buenos Aires Province (Argentina)
Pleistocene sediments, was associated to \emph{Holochilus}
and\emph{Lundomys} (Pardinas 2008). A still undescribed also giant
oryzomyine, probably a new genus closely related to \emph{Lundomys} , is
represented by a hemimaxillary unearthed from Late Pleistocene deposits
in southernmost Santa Fe Province (Argentina). Finally, the enigmatic
\selectlanguage{english}+\emph{Ichthyurodon ameghinoi} , originally described as a Pleistocene
Phyllotini (Steppan and Pardinas 1998) was reinterpreted as a
specialized Oryzomyini allied to \emph{Lundomys} (Barbiere 2019). If
these genera represent semiaquatic sigmodontines, a plausible hypothesis
based on craniodental morphology, bearing-sediments, associated fossil
taxa, and phylogeny (Carleton and Olson 1999, Machado et al. 2013), the
present unbalanced faunal scenario (semiaquatic versus terrestrial
sigmodontines) could be tempered.

Any working hypothesis has the risk to be discarded by speculative, more
in times when science is signed by a marked quantitative tendency. In
this context, concomitant evidences could bring additional support. A
past richest diversity of semiaquatic sigmodontines is not only limited
to extinct taxa but also to more ample geographical ranges. Selected
noticeable examples are the Quaternary occurrence of
\emph{Lundomys}registered from Minas Gerais in Brazil (Voss and Carleton
1993) to southern Buenos Aires Province in Argentina (Pardinas and Teta
2011). Its widespread past range (covering more than 15 degrees of
latitude) contrast with its current geographic distribution restricted
to less than 10 recording localities in Uruguay and southernmost Brazil
(Voss 2015b, Brandao and Fegies 2017). Large populations belonging
to\emph{Holochilus} have been recorded in Holocene deposits (Nuapua
locality) of southern Bolivian Chaco (Pardinas and Galliari 1998) where
today is neither \emph{Holochilus} nor permanent water (Coltorti et al.
2012). Extensive occurrence of the same genus is also recorded along the
Patagonian Rivers Limay and Negro as testify Holocene material from
archaeological sites (e.g. Fernandez et al. 2011, Pardinas and Teta
2011). Finally, the progressive loss of wetlands and associated mammals
during the last thousands of years was recurrent in western Argentina
(Lopez and Chiavazza 2021; Figure 2).

Up to this point and aimed to extract any biological worldwide signature
from the discussed topic seems relevant to compare sigmodontine
semiaquatic performance against other groups of muroids. The single
grossly equivalent subfamily, judged on richness and geographical
diversity is Murinae (Muridae), including about 145 genera and 656
species (Denys et al. 2017). This amazing muroid radiation,
characterized by a long history traced by confident fossils at least to
12 Ma (Kimura et al. 2021) and developed on four continents (i.e.,
Africa, Asia, Australia, and Europe) embraces very few members adapted
to fresh waters. Even considering jointly amphibious and ``waders,''
less of 10 genera can be highlighted (e.g., \emph{Colomys}
,\emph{Crossomys} , \emph{Dasymys} , \emph{Hydromys} ,
\emph{Nilopegamys} ,\emph{Waiomys} ; Helgen 2005, Rowe et al. 2014).
Taken uncritically these numbers, to note that this is a poorer
situation that the scenario showed by sigmodontines is obvious. To
observe that changing the framework the semiaquatic performance achieved
by the sigmodontines looks successful invites to further explorations.
To conclude that continental waterbodies resulted partially refractory
to muroid colonization seems indisputable.

The contemporary scarcity of semiaquatic sigmodontines seems the result
of a combination of an underexploited habitat (due to risk predation)
plus a pauperization process. Interestingly, even from fossil or current
record is Oryzomyini the single lineage to develop semiaquatic
specializations within the clade Oryzomyalia (a group currently
comprising 12 tribes; Pardinas et al. 2021). Ronez et al. (2021a) also
pointed out the uniqueness of oryzomyines in colonizing islands
partially highlighting their capacity to face marine barriers. Both
issues reinforce the idea that not all the tribes have the same
evolutionary capacity (or ecological opportunity? Alhajeri et al. 2016)
and this challenging notion can be representing a fresh avenue to
research sigmodontine history.

Literature cited

ALHAJERI, B.H., J.J. SCHENK \& S.J. STEPPAN. 2016. Ecomorphological
diversification following continental colonization in muroid rodents
(Rodentia: Muroidea). Biological Journal of the Linnean Society,
117:463--481.

AVILA-PIRES, F.D., 1972. A new subspecies of \emph{Kunsia fronto}(Winge,
1888) from Brazil (Rodentia, Cricetidae). Revista Brasileira de
Biologia, 32:419-422.

AYRES, J.M. \& T.H. CLUTTON-BROCK. 1992. River boundaries and species
range size in Amazonian primates. American Naturalist, 140:531--537.

BARBIERE, F. (2019). Estudio de la diversidad de sigmodontinos
(Mammalia, Rodentia) plio-pleistocenicos de Argentina, con enfasis en la
tribu Phyllotini (Unpublished doctoral dissertation). Universidad
Nacional de Tucuman, Argentina.

BARLOW, J.C., 1969. Observations on the biology of rodents in Uruguay.
Royal Ontario Museum, Life Science Contributions, 75:1-59.

BIANCHINI, J.C. \& H. DELUPI. 1993. Mammalia. In: Fauna de agua dulce de
la Republica Argentina (Zulma A. de Castellanos, dir.). 44, Fasc. 2
(Actualizacion), 79 pp., La Plata.

BONVICINO, C.R. \& M. WEKSLER. 2015. Genus \emph{Nectomys} Peters, 1861.
In: (J.L. Patton, U.F.J Pardinas and G. D'Elia, eds.) Mammals of South
America, Volume 2 -- Rodents. The University of Chicago Press, Chicago.
pp. 369--377.

BRITO, J., TINOCO, N., CURAY, J. \& PARDINAS, U.F.J. 2021. New
morphological data on the rare sigmodontine \emph{Mindomys
hammondi}(Rodentia, Cricetidae), an arboreal oryzomyine from
north-western Andean montane forests. Neotropical Biodiversity and
Conservation, 16(3): 397-410.

BRANDAO MV \& AC FEGIES. 2017. Range extension of \emph{Lundomys
molitor} (Winge, 1887) (Mammalia: Rodentia: Cricetidae) to eastern Rio
Grande do Sul state, Brazil. Check List 13(3): 2101.

CADENA E.-A., et al. 2020. The anatomy, paleobiology, and evolutionary
relationships of the largest extinct side-necked turtle. Science
Advances 6 (7): eaay4593.

CANDELA A, et al. 2023. The late Miocene mammals from the Humahuaca
Basin (Northwestern Argentina) provide new evidence on the initial
stages of the Great American Biotic Interchange. Papers in Paleontology,
in press.

CARLETON, M.D. \& S.L. OLSON. 1999. Amerigo Vespucci and the Rat of
Fernando de Noronha: a New Genus and Species of Rodentia (Muridae:
Sigmodontinae) from a Volcanic Island Off Brazil's Continental Shelf.
American Museum Novitates, 3256, 59 pp.

CARRILLO-BRICENO, J.D., A.E. REYES-CESPEDES, R. SALAS-GISMONDI AND R.
SANCHEZ. 2019. A new vertebrate continental assemblage from the
Tortonian of Venezuela. Swiss Journal of Palaeontology (2019)
138:237--248.

CASSINI, M.H. 2020. A review of the critics of invasion biology. Biol
Rev Camb Philos Soc 95(5):1467-1478.

CHIQUITO, E.A. 2015. Sistematica do genero \emph{Nectomys} Peters, 1861
(Cricetidae: Sigmodontinae). Doctoral Dissertation, Centro de Energia
Nuclear na Agricultura, Escola Superior de Agricultura ``Luiz de
Queiroz'', Universidade de Sao Paulo, Brazil.

CLAPPERTON, C. 1993. Quaternary geology and geomorphology of South
America. Elsevier, Amsterdam.

COLTORTI, M., J.D. FAZIA, F. PAREDES RIOS \& G. TITO. 2012. Nuagapua
(Chaco, Bolivia): Evidence for the latest occurrence of megafauna in
association with human remains in South America. Journal of South
American Earth Sciences 33 (2012) 56-67.

DENYS, C., P. J. TAYLOR \& K. P. APLIN. 2017. Family MURIDAE (TRUE MICE
AND RATS, GERBILS AND RELATIVES). In: Wilson DE, Lacher TE, Mittermeier
RA, eds. Handbook of the mammals of the world, volume 7. Rodents II.
Barcelona: Lynx Edicions, 536--597.

ESHER, R.J., WOLFE, J.L. \& LAYNE, J.N. 1978. Swimming behavior of Rice
Rats (\emph{Oryzomys palustris} ) and Cotton Rats (\emph{Sigmodon
hispidus} ). Journal of Mammalogy, 59: 551-558.

FERNANDEZ, F. J., L. DEL PAPA, G. J. MOREIRA, L. PRATES, \& L. J. M.

DE SANTIS. 2011. Small mammal remains recovered from two archaeological
sites in the middle and lower Negro River valley (Late Holocene,
Argentina): taphonomic issues and paleoenvironmental implications.
Quaternary International 245:136--147.

FISH, F. E. 1992. Aquatic locomotion. Pp. 34--63 in Mammalian
energetics: interdisciplinary views of metabolism and reproduction (T.
Tomasi and T. Horton, eds.). Cornell University Press, Ithaca, New York.

FISH, F. E., J. SMELSTOYS, R. V. BAUDINETTE, \& P. S. REYNOLDS. 2002.
Fur does not fly, it floats: buoyancy of pelage in semi-aquatic mammals.
Aquatic Mammals 28:103--112.

FORMOSO, A., UDRIZAR-SAUTHIER, D. \& PARDINAS, U. F. J. 2010. Mammalia,
Rodentia, Sigmodontinae, \emph{Holochilus brasiliensis} (Desmarest,
1819): distribution extention. Check List, Journal of Species List and
Distribution, 6(2):195-197.

HELGEN, K.M. (2005) The amphibious murines of New Guinea (Rodentia,
Muridae): the generic status of \emph{Baiyankamys} and description of a
new species of \emph{Hydromys} . Zootaxa, 913, 1--20.

HERSHKOVITZ, P. 1955. South American Marsh Rats, genus\emph{Holochilus}
, with a summary of sigmodont rodents. Fieldiana, Zoology, 37: 639-673 +
13 plates.

HERSHKOVITZ, P. 1966. South American swamp and fossorial rats of the
scapteromyine group (Cricetinae, Muridae), with comments on the glans
penis in murid taxonomy. Zeitschrift fur Saugetierkunde 31:81--149.

HERSHKOVITZ, P. 1969. The recent mammals of the Neotropical Region: A
zoogeographic and ecological review. The Quarterly Review of Biology
44:1--70

HERSHKOVITZ P. 1970. Supplementary notes on Neotropical \emph{Oryzomys
dimidiatus} and \emph{Oryzomys hammondi} (Cricetinae). Journal of
Mammalogy 51: 789--794.

HOFFSTETTER, R. 1963. La faune Pleistocene de Tarija (Bolivie). Note
preliminaire. Bulletin du Museum National D'Histoire Naturelle, 2eme
Serie, 35: 194--203.

HURLBERT, S.H., RODRIGUEZ, G. \& SANTOS, N.D. (Eds.). 1981. Aquatic
biota of Tropical South America, Part 2: Anarthropoda. San Diego State
University, San Diego, California, xi + 298 pp.

JUNK, W.J. 2007. Freshwater fishes of South America: Their biodiversity,
fisheries, and habitats---a synthesis, Aquatic Ecosystem Health \&
Management, 10:2, 228-242

JUNK, W.J. (2013). Current state of knowledge regarding South America
wetlands and their future under global climate change. Aquatic Sciences
75, 113-131.

KERBER, L., NEGRI, F.R., RIBEIRO, A.M., VUCETICH, M.G., \& DE
SOUZA-FILHO, J.P. 2016. Late Miocene potamarchine rodents from
southwestern Amazonia, Brazil---with description of new taxa. Acta
Palaeontologica Polonica 61 (1): 191--203.

KERBIS PETERHANS, J.C. \& B.D. PATTERSON. 1995. The Ethiopian water
mouse \emph{Nilopegamys} Osgood, with comments on semi-aquatic
adaptations in African Muridae. Zoological Journal of the Linnean
Society, 113: 329-349.

KIMURA Y, FLYNN LJ \& JACOBS LL (2021) Tempo and mode: Evidence on a
protracted split from a dense fossil record. Front. Ecol. Evol.
9:642814.

KNAPP, G.W., RAMOS, V.A., AVILA, H.F., MINKEL, C.W., GADE, D.W.,
GRIFFIN, E.C., GERMANI, G. \& DORST, J.P. 2021. South America.
Encyclopedia Britannica, February 7, 2021.
https://www.britannica.com/place/South-America.

LOPEZ, J.M. \& H. CHIAVAZZA. 2021. Ancient wetlands in the arid
environments of Central Western Argentina: a palaeoecological
perspective based on archaeological small mammal remains. Journal of
South American Earth Sciences 106 (2021) 103023.

LUNDBERG, J.G., L.G. MARSHALL, J. GUERRERO, B. HORTON, M. CLAUDIA, S.L.
MALABARBA, \& F.WESSELINGH. 1998. The stage for Neotropical fish
diversification: A history of tropical South American rivers. Pp. 13-48,
in (Malabarba LR, Reis RE, Vari RP, Lucena ZMS, Lucena CAS. Eds.)
Phylogeny and classification of Neotropical Fishes. Porto Alegre,
Edipucrs, 603 p.

MCDERMOTT, A. 2021. A sea in the Amazon. Did the Caribbean sweep into
the western Amazon millions of years ago, shaping the region's rich
biodiversity? PNAS 2021 Vol. 118 No. 10 e2102396118.

MACHADO, L.F., Y.L.R. LEITE, A.U. CHRISTOFF \& L.G. GIUGLIANO. 2014.
Phylogeny and biogeography of tetralophodont rodents of the tribe
Oryzomyini (Cricetidae: Sigmodontinae). Zool. Scri. 43: 119--130.

MAESTRI R, MONTEIRO LR, FORNEL R, UPHAM NS, PATTERSON BD, \& DE FREITAS
TRO. 2017. The ecology of a continental evolutionary radiation: is the
radiation of sigmodontine rodents

adaptive? Evolution 71(3):610--632.

MANN FISCHER G. 1978. Los pequenos mamiferos de Chile. Marsupiales,
quiropteros, edentados y roedores. Gayana, Zoologia 40: 1--342.

MASSOIA E. 1976. Mammalia. En: Fauna de Agua Dulce de la Republica
Argentina (R Ringuelet, dir.). Fundacion Editorial Ciencia y Cultura,
Buenos Aires 44:1-128.

MASSOIA, E. \& FORNES, A., 1964. Notas sobre el genero\emph{Scapteromys}
(Rodentia -Cricetidae). I. Sistematica, distribucion geografica y rasgos
etoecologicos de \emph{Scapteromys tumidus}(Waterhouse). Physis, Seccion
C, 24:279-297.

MILJUTIN A. 2010. Notes on the external morphology, ecology, and origin
of \emph{Megalomys desmarestii} (Sigmodontinae, Cricetidae, Rodentia),
the extinct rat of Martinique Island, Lesser Antilles. Estonianian
Journal of Ecology 59: 216--229.

MILLER, L.M. \& S. ANDERSON. 1977. Bodily proportions of Uruguayan
myomorph rodents. American Museum Novitates 2615, 1-10.

NORTHFIELD, T.D., B.S. GRETCHEN, A.R. IVES, \& W.E. SNYDER. 2010. Niche
saturation reveals resource partitioning among consumers. Ecol Lett
13(3):338-348.

PARADA, A., J. HANSON, \& G. D'ELIA. 2021. Ultraconserved elements
improve the resolution of difficult nodes within the rapid radiation of
Neotropical sigmodontine rodents (Cricetidae: Sigmodontinae). Systematic
Biology, in press.

PARDINAS, U.F.J. 2008. A new genus of oryzomyine rodent (Cricetidae:
Sigmodontinae) from the Pleistocene of Argentina. J. Mammal. 89:
1270--1278.

PARDINAS, U.F.J. \& BARBIERE, F. 2018. The Pleistocene record attributed
to the cricetid genus \emph{Nectomys} (Rodentia, Sigmodontinae):
Unexpected connections. Mammalia, 82(2): 201-206.

PARDINAS, U. F. J. \& GALLIARI, C. A. 1998. Sigmodontinos (Rodentia,
Muridae) del Holoceno inferior de Bolivia. Revista Espanola de
Paleontologia, 13 (1): 17-25, Madrid.

PARDINAS, U. F. J. \& TETA, P. 2011. Fossil history of the marsh rats of
the genus \emph{Holochilus} and \emph{Lundomys} (Cricetidae,
Sigmodontinae) in southern South America. Estudios Geologicos, 67 (1):
111-129.

PARDINAS, U.F.J., CIRIGNOLI, S., LABORDE, J. \& RICHIERI. A. 2004.
Nuevos datos sobre la distribucion de \emph{Irenomys tarsalis}(Philippi,
1900) (Rodentia: Sigmodontinae) en Argentina. Mastozoologia Neotropical,
11: 99-104.

PARDINAS, U.F.J., CURAY, J., BRITO, J. \& CANON, C. 2021. A unique
cricetid experiment in the northern high--Andean Paramos deserves tribal
recognition. Journal of Mammalogy, Journal of Mammalogy,
102(1):155--172, 2021. DOI:10.1093/jmammal/gyaa147.

PARDINAS, U. F. J., D'ELIA, G. \& ORTIZ, P. E. 2003. Sigmodontinos
fosiles (Rodentia, Muroidea, Sigmodontinae) de America del Sur: estado
actual de su conocimiento y prospectiva. Mastozoologia Neotropical, 9
(2): 209-252.

PARDINAS, U. F. J., D'ELIA, G. \& TETA, P. 2008 {[}2009{]}. Una
introduccion a los mayores sigmodontinos vivientes: revision
de\emph{Kunsia} Hershkovitz, 1966 y descripcion de un nuevo genero
(Rodentia: Cricetidae). Arquivos do Museu Nacional, Rio de Janeiro, 66
(3-4): 509-594.

PARDINAS UFJ, MYERS P, LEON-PANIAGUA L, ORDONEZ-GARZA N, COOK J,
KRY\selectlanguage{polish}Š\selectlanguage{english}TUFEK B, HASLAUER R, BRADLEY R, SHENBROT G, \& PATTON J. 2017a.
Family Cricetidae (true hamsters, voles, lemmings and New World rats and
mice). In: Wilson DE, Lacher TE, Mittermeier RA, eds. Handbook of the
mammals of the world, volume 7. Rodents II. Barcelona: Lynx Edicions,
204--279.

PARDI\selectlanguage{ngerman}ÑAS, U.F.J., TETA, P. \& SALAZAR-BRAVO, J. 2015. A new tribe of
Sigmodontinae rodents (Cricetidae). Mastozoología Neotropical, 22 (1):
171-186.

PARDIÑAS, U.F.J., TETA, P., VOGLINO, D., \& FERNÁNDEZ, F. 2013.
Enlarging rodent diversity in west-central Argentina: a new species of
the genus \emph{Holochilus} (Cricetidae, Sigmodontinae). Journal of
Mammalogy, 94(1):231-240.

PATTON, J.L., U.F.J. PARDIÑAS \& G. D'ELÍA. 2015. Mammals of South
America, Volume 2: Rodents. University of Chicago Press, Chicago,
Illinois. pp. 1336.

PEARSON, O.P. 1951. Mammals in the highlands of southern Peru. Bull.
Mus. Comp. Zool. 106(3):117-- 174.

PERCEQUILLO AR, PRADO JRD, ABREU EF, DALAPICOLLA J, PAVAN AC, DE ALMEIDA
CHIQUITO E, BRENNAND P, STEPPAN SJ, LEMMON AR, LEMMON EM, \& WILKINSON
M. 2021. Tempo and mode of evolution of oryzomyine rodents (Rodentia,
Cricetidae, Sigmodontinae): a phylogenomic approach. Molecular
Phylogenetics and Evolution 159:107120.

PINE, R. H., N. E. PINE \& S. D. BRUNER. 1981. Mammalia. Pp. 267-298,
in: Aquatic Biota of Tropical South America, Part 2: Anarthropoda
(Hurlbert, S. H., G. Rodriguez and N. D. Santos, eds.). San Diego State
University, San Diego, California.

PRADO, J.R., L.L. KNOWLES \& A.R. PERCEQUILLO. 2021. New species
boundaries and the diversification history of marsh rat taxa clarify
historical connections among ecologically and geographically distinct
wetlands of South America. Molecular Phylogenetics and Evolution 155
(2021) 106992.

PREVOSTI, F. J., ROMANO, C., FORASIEPI, A., HEMMING, S., BONINI, R.,
CANDELA, A., CERDEÑO, E., MADDOZO JAEN, M. C., ORTÍZ, P., PUJOS, F.,
RASIA, L., SCHMIDT, G., TAGLIORETTI, M., MACPHEE, R., \& PARDIÑAS, U. F.
J. 2021. New radiometric 40Ar--39Ar dates and faunistic analyses refine
evolutionary dynamics of Neogene vertebrate assemblages in southern
South America. Scientific Reports 11:9830.

REIS, R. E., J. S. ALBERT, F. DI DARIO, M. M. MINCARONE, P. PETRY \& L.
A. ROCHA. 2016. Fish biodiversity and conservation in South America.
Journal of Fish Biology doi:10.1111/jfb.13016

ROMANO CO, R BONINI, S HEMMING, M CENIZO, UFJ PARDIÑAS, \& FJ PREVOSTI.
2023. Advances in the understanding of Neogene mammalian fauna in the
Pampean region (Central Argentina) through revising ``biozone''
hypotheses based on new dates and biochronological analyses.
Ameghiniana, in press.

RONEZ, C., BRITO, J., HUTTERER, R., MARTIN, R. \& PARDIÑAS, U.F.J.
2021a. Tribal allocation and biogeographical significance of one of the
largest sigmodontine rodent, the extinct Galápagos
\emph{Megaoryzomys}(Cricetidae). Historical Biology, 33: 1920-1932.

RONEZ C, JD CARRILLO-BRICEÑO, P HADLER, MR SÁNCHEZ-VILLAGRA \& UFJ
PARDIÑAS. 2023. Pliocene sigmodontine rodents (Mammalia: Cricetidae) in
Northernmost South America: test of biogeographic hypotheses and revised
evolutionary scenarios. Royal Society Open Science, in press.

RONEZ, C., R.A. MARTIN, T.S. KELLY, F. BARBIÈRE \& U.F.J. PARDIÑAS.
2021b. A brief critical review of sigmodontine rodent origins, with
emphasis on paleontological data. Mastozoología Neotropical,
https://doi.org/10.31687/saremMN.21.28.1.0.07

ROWE K. C., A. S. ACHMADI \& J. A. ESSELSTYN. 2014. Convergent evolution
of aquatic foraging in a new genus and species (Rodentia: Muridae) from
Sulawesi Island, Indonesia. Zootaxa 3815 (4): 541--564.

SÁNCHEZ-VILLAGRA, M.R., O.A. AGUILERA, \& A.A. CARLINI (eds). 2010.
Urumaco and Venezuelan paleontology: The fossil record of the northern
Neotropics. Bloomington: Indiana University Press. 286 pp.

SIERRA DE SORIANO, B. 1965. Algunas estructuras externas relacionadas
con la vida anfibia en dos especies del género \emph{Holochilus} Brandt,
1835, (Muridae, Cricetinae). Revista de la Facultad de Humanidades y
Ciencias, 22:209-220.

SIERRA DE SORIANO, B. 1969. Algunos caracteres externos de cricetinos y
su relación con el grado de adaptación a la vida acuática (Rodentia).
Physis, 28 (77): 471-486.

SALAZAR-BRAVO J, TINOCO N, ZEBALLOS H, BRITO J, ARENAS-VIVEROS D,
MARÍN-C D, RAMÍREZ-FERNÁNDEZ JD, PERCEQUILLO AR, LEE, JR. TE, SOLARI S,
COLMENARES-PINZON J, NIVELO C, RODRÍGUEZ HERRERA B, MERINO W, MEDINA CE,
MURILLO-GARCÍA O, PARDIÑAS UFJ. 2023. Systematics and diversification of
the Ichthyomyini (Cricetidae, Sigmodontinae) revisited: evidence from
molecular, morphological, and combined approaches. PeerJ 11:e14319
https://doi.org/10.7717/peerj.14319

SANTORI, R.T., M.V. VIEIRA, O. ROCHA-BARBOSA, J.A. MAGNAN-NETO, \& N.
GOBBI. 2008. Water absorption of the fur and swimming behavior of
semiaquatic and terrestrial oryzomine rodents. Journal of Mammalogy,
89(5):1152--1161.

STARRETT, A., \& G. F. FISLER.1970. Aquatic adaptations of the water
mouse, \emph{Rheomys underwoodi} . Contrib. Sci., Los Angeles Co. Mus.,
182: 1-14.

STEIN, B.R. \& J.L. PATTON. 2008. Genus \emph{Chironectes} Illiger,
1811. In: (A.L. Gardner, ed.) Mammals of South America, Volume 1 --
marsupials, xenarthrans, shrews, and bats. The University of Chicago
Press, Chicago. pp. 14--17.

STEPPAN, S.J. 1996. A new species of \emph{Holochilus} (Rodentia:
Sigmodontinae) from the middle Pleistocene of Bolivia and its
phylogenetic significance. J. Vert. Paleontol. 16: 522--530.

STEPPAN, S. J. \& PARDIÑAS, U. F. J. 1998. Two new fossil muroids
(Sigmodontinae: Phyllotini) from the Early Pleistocene of Argentina:
phylogeny and paleoecology. Journal of Vertebrate Paleontology, 18 (3):
640-649, Lawrence.

VITULE, J.R.S., M.O. FREITAS, V.M. RIBEIRO \& H. BORNATOWSKI. 2015.
First records of Sigmodontinae (Mammalia) predation by \emph{Oligosarcus
hepsetus} (Cuvier, 1829) (Characiformes, Characidae) in Atlantic Rain
Forest rivers of southern Brazil. Pan-American Journal of Aquatic
Sciences 10(4): 328-331.

VOSS RS. 1988. Systematics and ecology of ichthyomyine rodents
(Muroidea): patterns of morphological evolution in a small adaptive
radiation. Bulletin of the American Museum of Natural History 188:
258--493.

VOSS RS. 2015a. Tribe Ichthyomyini Vorontsov, 1959. In: Patton JL,
Pardiñas UFJ, D'Elía G, eds.

Mammals of South America, Vol 2 - Rodents. Vol. 2. Chicago, London: The
University of

Chicago Press, 279--291.

VOSS RS. 2015b. Genus \emph{Lundomys} Voss and Carleton, 1993. In:
Patton JL, Pardiñas UFJ, D'Elía G, eds. Mammals of South America, Vol 2
- Rodents. Vol. 2. Chicago, London: The University of

Chicago Press, 346--348.

VOSS, R.S. \& CARLETON, M.D., 1993. A new genus for \emph{Hesperomys
molitor} Winge and \emph{Holochilus magnus} Hershkovitz, with comments
on phylogenetic relationships and oryzomyine monophyly. American Museum
Novitates, 3085:1-39.

VOSS, R.S. \& MYERS, P., 1991. \emph{Pseudoryzomys simplex} (Rodentia:
Muridae) and the significance of Lund's collections from the caves of
Lagoa Santa, Brazil. Bulletin of the American Museum of Natural History,
206:414-432.

VUCETICH, M.G., ARNAL, M., DESCHAMPS, C.M., PÉREZ, M.E., \& VIEYTES,
E.C. 2015. A brief history of caviomorph rodents as told by the fossil
record. In: A.I. Vasallo, and D. Antenucci (Eds.), Biology of caviomorph
rodents: diversity and evolution. SAREM Series A, Mammalogical Research,
Sociedad Argentina para el Estudio de los Mamíferos, Mendoza, p. 11--62.

WOLFF, J.O. \& R.D. GUTHRIE. 1985. Why are aquatic small mammals so
large? Oikos 45: 365-373.

Figure legends

Figure 1. Generalized distributions of the two sigmodontine rodent
groups containing semiaquatic forms superimposed on a map of Middle and
South America highlighting current main fluvial systems.

Figure 2. Some of the fossil craniodental remains of sigmodontines
conjectured to be semiaquatic extinguished taxa plus Pleistocene maximum
range of the \emph{Lundomys molitor} (colored area to the right) and
Holocene extension of the distribution of \emph{Holochilus} (colored
area to the left). Based on several sources.

Data Accessibilty Statement

The datasets generated and analyzed during the current study are
included (Appendix 1); fossils mentioned or discussed are available in
the following public biological repositories: CNP: Colección de
Mamíferos, Centro Nacional Patagónico, Puerto Madryn, Chubut,

Argentina; FMNH: Field Museum, Chicago, Illinois, United States; MLP:
Museo de La Plata, La Plata, Argentina.

Competing Interests Statement

The authors declare no conflict of interest.

Author Contributions section

UFJP and ECC contribute equally to the conceptualization, design, and
writing of this contribution.

Acknowledgements

The topic treated here was enriched through discussions, during field
works and through years, with C. Galliari. S. Bogan helped with valuable
bibliography and his huge knowledge on recent and fossil fishes; F.
Carlini also shared literature. This manuscript was completed during a
sabbatical term spend by the senior author at the Oman National Natural
History Museum (Muscat, Oman). Cabinet work was funded by Agencia grant
(PICT) 2020-2068.

Appendix 1. A list of living genera and species of sigmodontine rodents
indicating those considered semiaquatic and ``waders.'' Compilation
based largely on Patton et al. (2015) and Pardiñas et al. (2017) with
modifications; numbers updated to May 2023.\selectlanguage{english}
\begin{longtable}[]{@{}lllllll@{}}
\toprule
& \textbf{Total} & \textbf{Total} & \textbf{Semiaquatic} &
\textbf{Semiaquatic} & \textbf{''Waders''} &
\textbf{''Waders''}\tabularnewline
\midrule
\endhead
& \textbf{Genera} & \textbf{Species} & \textbf{Genera} &
\textbf{Species} & \textbf{Genera} & \textbf{Species}\tabularnewline
ORYZOMYALIA & & & & & &\tabularnewline
INCERTAE SEDIS & & & & & &\tabularnewline
\emph{ABRAWAYAOMYS} & 1 & & & & &\tabularnewline
\emph{Abrawayaomys chebezi} & & 1 & & & &\tabularnewline
\emph{Abrawayaomys ruschii} & & 1 & & & &\tabularnewline
\emph{CHINCHILLULA} & 1 & & & & &\tabularnewline
\emph{Chinchillula sahamae} & & 1 & & & &\tabularnewline
\emph{DELOMYS} & 1 & & & & &\tabularnewline
\emph{Delomys altimontanus} & & 1 & & & &\tabularnewline
\emph{Delomys dorsalis} & & 1 & & & &\tabularnewline
\emph{Delomys sublineatus} & & 1 & & & &\tabularnewline
ABROTRICHINI & & & & & &\tabularnewline
\emph{ABROTHRIX} & 1 & & & & &\tabularnewline
\emph{Abrothrix andina} & & 1 & & & &\tabularnewline
\emph{Abrothrix hirta} & & 1 & & & &\tabularnewline
\emph{Abrothrix illutea} & & 1 & & & &\tabularnewline
\emph{Abrothrix jelskii} & & 1 & & & &\tabularnewline
\emph{Abrothrix lanosa} & & 1 & & & &\tabularnewline
\emph{Abrothrix longipilis} & & 1 & & & &\tabularnewline
\emph{Abrothrix manni} & & 1 & & & &\tabularnewline
\emph{Abrothrix olivacea} & & 1 & & & &\tabularnewline
\emph{Abrothrix sanborni} & & 1 & & & &\tabularnewline
\emph{Abrothrix xanthorhina} & & 1 & & & &\tabularnewline
\emph{CHELEMYS} & 1 & & & & &\tabularnewline
\emph{Chelemys megalonyx} & & 1 & & & &\tabularnewline
\emph{GEOXUS} & 1 & & & & &\tabularnewline
\emph{Geoxus annectens} & & 1 & & & &\tabularnewline
\emph{Geoxus lafkenche} & & 1 & & & &\tabularnewline
\emph{Geoxus michaelseni} & & 1 & & & &\tabularnewline
\emph{Geoxus valdivianus} & & 1 & & & &\tabularnewline
\emph{NOTIOMYS} & 1 & & & & &\tabularnewline
\emph{Notiomys edwardsii} & & 1 & & & &\tabularnewline
\emph{PAYNOMYS} & 1 & & & & &\tabularnewline
\emph{Paynomys macronyx} & & 1 & & & &\tabularnewline
AKODONTINI & & & & & &\tabularnewline
\emph{AKODON} & 1 & & & & &\tabularnewline
\emph{Akodon aerosus} & & 1 & & & &\tabularnewline
\emph{Akodon affinis} & & 1 & & & &\tabularnewline
\emph{Akodon albiventer} & & 1 & & & &\tabularnewline
\emph{Akodon azarae} & & 1 & & & &\tabularnewline
\emph{Akodon baliolus} & & 1 & & & &\tabularnewline
\emph{Akodon boliviensis} & & 1 & & & &\tabularnewline
\emph{Akodon budini} & & 1 & & & &\tabularnewline
\emph{Akodon caenosus} & & 1 & & & &\tabularnewline
\emph{Akodon cursor} & & 1 & & & &\tabularnewline
\emph{Akodon dayi} & & 1 & & & &\tabularnewline
\emph{Akodon diauarum} & & 1 & & & &\tabularnewline
\emph{Akodon dolores} & & 1 & & & &\tabularnewline
\emph{Akodon fumeus} & & 1 & & & &\tabularnewline
\emph{Akodon iniscatus} & & 1 & & & &\tabularnewline
\emph{Akodon josemariarguedasi} & & 1 & & & &\tabularnewline
\emph{Akodon juninensis} & & 1 & & & &\tabularnewline
\emph{Akodon kadiweu} & & 1 & & & &\tabularnewline
\emph{Akodon kofordi} & & 1 & & & &\tabularnewline
\emph{Akodon kotosh} & & 1 & & & &\tabularnewline
\emph{Akodon lindberghi} & & 1 & & & &\tabularnewline
\emph{Akodon lutescens} & & 1 & & & &\tabularnewline
\emph{Akodon mollis} & & 1 & & & &\tabularnewline
\emph{Akodon montensis} & & 1 & & & &\tabularnewline
\emph{Akodon mystax} & & 1 & & & &\tabularnewline
\emph{Akodon oenos} & & 1 & & & &\tabularnewline
\emph{Akodon orophilus} & & 1 & & & &\tabularnewline
\emph{Akodon paranaensis} & & 1 & & & &\tabularnewline
\emph{Akodon pervalens} & & 1 & & & &\tabularnewline
\emph{Akodon philipmyersi} & & 1 & & & &\tabularnewline
\emph{Akodon polopi} & & 1 & & & &\tabularnewline
\emph{Akodon reigi} & & 1 & & & &\tabularnewline
\emph{Akodon sanctipaulensis} & & 1 & & & &\tabularnewline
\emph{Akodon siberiae} & & 1 & & & &\tabularnewline
\emph{Akodon simulator} & & 1 & & & &\tabularnewline
\emph{Akodon spegazzinii} & & 1 & & & &\tabularnewline
\emph{Akodon subfuscus} & & 1 & & & &\tabularnewline
\emph{Akodon surdus} & & 1 & & & &\tabularnewline
\emph{Akodon sylvanus} & & 1 & & & &\tabularnewline
\emph{Akodon toba} & & 1 & & & &\tabularnewline
\emph{Akodon torques} & & 1 & & & &\tabularnewline
\emph{Akodon varius} & & 1 & & & &\tabularnewline
\emph{BIBIMYS} & 1 & & & & &\tabularnewline
\emph{Bibimys chacoensis} & & 1 & & & &\tabularnewline
\emph{Bibimys labiosus} & & 1 & & & &\tabularnewline
\emph{Bibimys torresi} & & 1 & & & &\tabularnewline
\emph{BLARINOMYS} & 1 & & & & &\tabularnewline
\emph{Blarinomys breviceps} & & 1 & & & &\tabularnewline
\emph{BRUCEPATTERSONIUS} & 1 & & & & &\tabularnewline
\emph{Brucepattersonius griserufescens} & & 1 & & & &\tabularnewline
\emph{Brucepattersonius iheringi} & & 1 & & & &\tabularnewline
\emph{Brucepattersonius nebulosus} & & 1 & & & &\tabularnewline
\emph{Brucepattersonius soricinus} & & 1 & & & &\tabularnewline
\emph{CASTORIA} & 1 & & & & &\tabularnewline
\emph{Castoria angustidens} & & 1 & & & &\tabularnewline
\emph{DELTAMYS} & 1 & & & & &\tabularnewline
\emph{Deltamys araucaria} & & 1 & & & &\tabularnewline
\emph{Deltamys kempi} & & 1 & & & &\tabularnewline
\emph{GYLDENSTOLPIA} & 1 & & & & 1 &\tabularnewline
\emph{Gyldenstolpia fronto} & & 1 & & & & 1\tabularnewline
\emph{Gyldenstolpia planaltensis} & & 1 & & & & 1\tabularnewline
\emph{JUSCELINOMYS} & 1 & & & & &\tabularnewline
\emph{Juscelinomys candango} & & 1 & & & &\tabularnewline
\emph{Juscelinomys huanchacae} & & 1 & & & &\tabularnewline
\emph{KUNSIA} & 1 & & & & &\tabularnewline
\emph{Kunsia tomentosus} & & 1 & & & &\tabularnewline
\emph{LENOXUS} & 1 & & & & &\tabularnewline
\emph{Lenoxus apicalis} & & 1 & & & &\tabularnewline
\emph{MICROXUS} & 1 & & & & &\tabularnewline
\emph{Microxus mimus} & & 1 & & & &\tabularnewline
\emph{NECROMYS} & 1 & & & & &\tabularnewline
\emph{Necromys amoenus} & & 1 & & & &\tabularnewline
\emph{Necromys lactens} & & 1 & & & &\tabularnewline
\emph{Necromys lasiurus} & & 1 & & & &\tabularnewline
\emph{Necromys lilloi} & & 1 & & & &\tabularnewline
\emph{Necromys obscurus} & & 1 & & & &\tabularnewline
\emph{Necromys punctulatus} & & 1 & & & &\tabularnewline
\emph{Necromys urichi} & & 1 & & & &\tabularnewline
\emph{OXYMYCTERUS} & 1 & & & & &\tabularnewline
\emph{Oxymycterus amazonicus} & & 1 & & & &\tabularnewline
\emph{Oxymycterus caparoae} & & 1 & & & &\tabularnewline
\emph{Oxymycterus dasytrichus} & & 1 & & & &\tabularnewline
\emph{Oxymycterus delator} & & 1 & & & &\tabularnewline
\emph{Oxymycterus hiska} & & 1 & & & &\tabularnewline
\emph{Oxymycterus hucucha} & & 1 & & & &\tabularnewline
\emph{Oxymycterus inca} & & 1 & & & &\tabularnewline
\emph{Oxymycterus itapeby} & & 1 & & & &\tabularnewline
\emph{Oxymycterus josei} & & 1 & & & &\tabularnewline
\emph{Oxymycterus juliacae} & & 1 & & & &\tabularnewline
\emph{Oxymycterus nasutus} & & 1 & & & &\tabularnewline
\emph{Oxymycterus nigrifrons} & & 1 & & & &\tabularnewline
\emph{Oxymycterus paramensis} & & 1 & & & &\tabularnewline
\emph{Oxymycterus quaestor} & & 1 & & & &\tabularnewline
\emph{Oxymycterus rufus} & & 1 & & & &\tabularnewline
\emph{Oxymycterus wayku} & & 1 & & & &\tabularnewline
\emph{Oxymycterus willkaurco} & & 1 & & & &\tabularnewline
\emph{PODOXYMYS} & 1 & & & & &\tabularnewline
\emph{Podoxymys roraimae} & & 1 & & & &\tabularnewline
\emph{SCAPTEROMYS} & 1 & & & & 1 &\tabularnewline
\emph{Scapteromys aquaticus} & & 1 & & & & 1\tabularnewline
\emph{Scapteromys meridionalis} & & 1 & & & & 1\tabularnewline
\emph{Scapteromys tumidus} & & 1 & & & & 1\tabularnewline
\emph{THALPOMYS} & 1 & & & & &\tabularnewline
\emph{Thalpomys cerradensis} & & 1 & & & &\tabularnewline
\emph{Thalpomys lasiotis} & & 1 & & & &\tabularnewline
\emph{THAPTOMYS} & 1 & & & & &\tabularnewline
\emph{Thaptomys nigrita} & & 1 & & & &\tabularnewline
ANDINOMYINI & & & & & &\tabularnewline
\emph{ANDINOMYS} & 1 & & & & &\tabularnewline
\emph{Andinomys edax} & & 1 & & & &\tabularnewline
\emph{PUNOMYS} & 1 & & & & &\tabularnewline
\emph{Punomys kofordi} & & 1 & & & &\tabularnewline
\emph{Punomys lemminus} & & 1 & & & &\tabularnewline
EUNEOMYINI & & & & & &\tabularnewline
\emph{EUNEOMYS} & 1 & & & & &\tabularnewline
\emph{Euneomys chinchilloides} & & 1 & & & &\tabularnewline
\emph{Euneomys fossor} & & 1 & & & &\tabularnewline
\emph{Euneomys mordax} & & 1 & & & &\tabularnewline
\emph{Euneomys petersoni} & & 1 & & & &\tabularnewline
\emph{IRENOMYS} & 1 & & & & &\tabularnewline
\emph{Irenomys tarsalis} & & 1 & & & &\tabularnewline
\emph{NEOTOMYS} & 1 & & & & &\tabularnewline
\emph{Neotomys ebriosus} & & 1 & & & &\tabularnewline
NEOMICROXINI & & & & & &\tabularnewline
\emph{NEOMICROXUS} & 1 & & & & &\tabularnewline
\emph{Neomicroxus bogotensis} & & 1 & & & &\tabularnewline
\emph{Neomicroxus latebricola} & & 1 & & & &\tabularnewline
ORYZOMYINI & & & & & &\tabularnewline
\emph{''HANDLEYOMYS''} & 1 & & & & &\tabularnewline
\emph{``Handleyomys'' alfaroi} & & 1 & & & &\tabularnewline
\emph{``Handleyomys'' chapmani} & & 1 & & & &\tabularnewline
\emph{``Handleyomys'' guerrerensis} & & 1 & & & &\tabularnewline
\emph{``Handleyomys'' melanotis} & & 1 & & & &\tabularnewline
\emph{``Handleyomys'' rhabdops} & & 1 & & & &\tabularnewline
\emph{``Handleyomys'' rostratus} & & 1 & & & &\tabularnewline
\emph{``Handleyomys'' saturatior} & & 1 & & & &\tabularnewline
\emph{AEGIALOMYS} & 1 & & & & &\tabularnewline
\emph{Aegialomys baroni} & & 1 & & & &\tabularnewline
\emph{Aegialomys galapagoensis} & & 1 & & & &\tabularnewline
\emph{Aegialomys ica} & & 1 & & & &\tabularnewline
\emph{Aegialomys xanthaeolus} & & 1 & & & &\tabularnewline
\emph{AMPHINECTOMYS} & 1 & & 1 & & &\tabularnewline
\emph{Amphinectomys savamis} & & 1 & & 1 & &\tabularnewline
\emph{CERRADOMYS} & 1 & & & & &\tabularnewline
\emph{Cerradomys akroai} & & 1 & & & &\tabularnewline
\emph{Cerradomys goytaca} & & 1 & & & &\tabularnewline
\emph{Cerradomys langguthi} & & 1 & & & &\tabularnewline
\emph{Cerradomys maracajuensis} & & 1 & & & &\tabularnewline
\emph{Cerradomys marinhus} & & 1 & & & &\tabularnewline
\emph{Cerradomys scotti} & & 1 & & & &\tabularnewline
\emph{Cerradomys subflavus} & & 1 & & & &\tabularnewline
\emph{Cerradomys vivoi} & & 1 & & & &\tabularnewline
\emph{DRYMOREOMYS} & 1 & & & & &\tabularnewline
\emph{Drymoreomys albimaculatus} & & 1 & & & &\tabularnewline
\emph{EREMORYZOMYS} & 1 & & & & &\tabularnewline
\emph{Eremoryzomys mesocaudis} & & 1 & & & &\tabularnewline
\emph{Eremoryzomys polius} & & 1 & & & &\tabularnewline
\emph{EURYORYZOMYS} & 1 & & & & &\tabularnewline
\emph{Euryoryzomys emmonsae} & & 1 & & & &\tabularnewline
\emph{Euryoryzomys lamia} & & 1 & & & &\tabularnewline
\emph{Euryoryzomys legatus} & & 1 & & & &\tabularnewline
\emph{Euryoryzomys macconnelli} & & 1 & & & &\tabularnewline
\emph{Euryoryzomys nitidus} & & 1 & & & &\tabularnewline
\emph{Euryoryzomys russatus} & & 1 & & & &\tabularnewline
\emph{HANDLEYOMYS} & 1 & & & & &\tabularnewline
\emph{Handleyomys fuscatus} & & 1 & & & &\tabularnewline
\emph{Handleyomys intectus} & & 1 & & & &\tabularnewline
\emph{HOLOCHILUS} & 1 & & 1 & & &\tabularnewline
\emph{Holochilus brasiliensis} & & 1 & & 1 & &\tabularnewline
\emph{Holochilus chacarius} & & 1 & & 1 & &\tabularnewline
\emph{Holochilus lagigliai} & & 1 & & 1 & &\tabularnewline
\emph{Holochilus nanus} & & 1 & & 1 & &\tabularnewline
\emph{Holochilus oxe} & & 1 & & 1 & &\tabularnewline
\emph{Holochilus sciureus} & & 1 & & 1 & &\tabularnewline
\emph{Holochilus venezuelae} & & 1 & & 1 & &\tabularnewline
\emph{HYLAEAMYS} & 1 & & & & &\tabularnewline
\emph{Hylaeamys acritus} & & 1 & & & &\tabularnewline
\emph{Hylaeamys laticeps} & & 1 & & & &\tabularnewline
\emph{Hylaeamys megacephalus} & & 1 & & & &\tabularnewline
\emph{Hylaeamys oniscus} & & 1 & & & &\tabularnewline
\emph{Hylaeamys perenensis} & & 1 & & & &\tabularnewline
\emph{Hylaeamys tatei} & & 1 & & & &\tabularnewline
\emph{Hylaeamys yunganus} & & 1 & & & &\tabularnewline
\emph{LUNDOMYS} & 1 & & 1 & & &\tabularnewline
\emph{Lundomys molitor} & & 1 & & 1 & &\tabularnewline
\emph{MELANOMYS} & 1 & & & & &\tabularnewline
\emph{Melanomys caliginosus} & & 1 & & & &\tabularnewline
\emph{Melanomys chrysomelas} & & 1 & & & &\tabularnewline
\emph{Melanomys columbianus} & & 1 & & & &\tabularnewline
\emph{Melanomys idoneus} & & 1 & & & &\tabularnewline
\emph{Melanomys robustulus} & & 1 & & & &\tabularnewline
\emph{Melanomys zunigae} & & 1 & & & &\tabularnewline
\emph{MICROAKODONTOMYS} & 1 & & & & &\tabularnewline
\emph{Microakodontomys transitorius} & & 1 & & & &\tabularnewline
\emph{MICRORYZOMYS} & 1 & & & & &\tabularnewline
\emph{Microryzomys altissimus} & & 1 & & & &\tabularnewline
\emph{Microryzomys minutus} & & 1 & & & &\tabularnewline
\emph{MINDOMYS} & 1 & & & & &\tabularnewline
\emph{Mindomys hammondi} & & 1 & & & &\tabularnewline
\emph{Mindomys kutuku} & & 1 & & & &\tabularnewline
\emph{NEACOMYS} & 1 & & & & &\tabularnewline
\emph{Neacomys aletheia} & & 1 & & & &\tabularnewline
\emph{Neacomys amoenus} & & 1 & & & &\tabularnewline
\emph{Neacomys auriventer} & & 1 & & & &\tabularnewline
\emph{Neacomys carceleni} & & 1 & & & &\tabularnewline
\emph{Neacomys dubosti} & & 1 & & & &\tabularnewline
\emph{Neacomys elieceri} & & 1 & & & &\tabularnewline
\emph{Neacomys guianae} & & 1 & & & &\tabularnewline
\emph{Neacomys jau} & & 1 & & & &\tabularnewline
\emph{Neacomys leilae} & & 1 & & & &\tabularnewline
\emph{Neacomys macedoruizi} & & 1 & & & &\tabularnewline
\emph{Neacomys marajoara} & & 1 & & & &\tabularnewline
\emph{Neacomys minutus} & & 1 & & & &\tabularnewline
\emph{Neacomys musseri} & & 1 & & & &\tabularnewline
\emph{Neacomys oliveirai} & & 1 & & & &\tabularnewline
\emph{Neacomys paracou} & & 1 & & & &\tabularnewline
\emph{Neacomys pictus} & & 1 & & & &\tabularnewline
\emph{Neacomys rosalindae} & & 1 & & & &\tabularnewline
\emph{Neacomys serranensis} & & 1 & & & &\tabularnewline
\emph{Neacomys spinosus} & & 1 & & & &\tabularnewline
\emph{Neacomys tenuipes} & & 1 & & & &\tabularnewline
\emph{Neacomys vargasllosai} & & 1 & & & &\tabularnewline
\emph{Neacomys vossi} & & 1 & & & &\tabularnewline
\emph{Neacomys xingu} & & 1 & & & &\tabularnewline
\emph{NECTOMYS} & 1 & & 1 & & &\tabularnewline
\emph{Nectomys apicalis} & & 1 & & 1 & &\tabularnewline
\emph{Nectomys magdalenae} & & 1 & & 1 & &\tabularnewline
\emph{Nectomys palmipes} & & 1 & & 1 & &\tabularnewline
\emph{Nectomys rattus} & & 1 & & 1 & &\tabularnewline
\emph{Nectomys saturatus} & & 1 & & 1 & &\tabularnewline
\emph{Nectomys squamipes} & & 1 & & 1 & &\tabularnewline
\emph{NEPHELOMYS} & 1 & & & & &\tabularnewline
\emph{Nephelomys albigularis} & & 1 & & & &\tabularnewline
\emph{Nephelomys auriventer} & & 1 & & & &\tabularnewline
\emph{Nephelomys caracolus} & & 1 & & & &\tabularnewline
\emph{Nephelomys childi} & & 1 & & & &\tabularnewline
\emph{Nephelomys devius} & & 1 & & & &\tabularnewline
\emph{Nephelomys keaysi} & & 1 & & & &\tabularnewline
\emph{Nephelomys levipes} & & 1 & & & &\tabularnewline
\emph{Nephelomys maculiventer} & & 1 & & & &\tabularnewline
\emph{Nephelomys meridensis} & & 1 & & & &\tabularnewline
\emph{Nephelomys moerex} & & 1 & & & &\tabularnewline
\emph{Nephelomys nimbosus} & & 1 & & & &\tabularnewline
\emph{Nephelomys pectoralis} & & 1 & & & &\tabularnewline
\emph{Nephelomys pirrensis} & & 1 & & & &\tabularnewline
\emph{Nephelomys ricardopalmai} & & 1 & & & &\tabularnewline
\emph{NESORYZOMYS} & 1 & & & & &\tabularnewline
\emph{Nesoryzomys fernandinae} & & 1 & & & &\tabularnewline
\emph{Nesoryzomys narboroughi} & & 1 & & & &\tabularnewline
\emph{Nesoryzomys swarthi} & & 1 & & & &\tabularnewline
\emph{OECOMYS} & 1 & & & & &\tabularnewline
\emph{Oecomys auyantepui} & & 1 & & & &\tabularnewline
\emph{Oecomys bicolor} & & 1 & & & &\tabularnewline
\emph{Oecomys catherinae} & & 1 & & & &\tabularnewline
\emph{Oecomys cleberi} & & 1 & & & &\tabularnewline
\emph{Oecomys concolor} & & 1 & & & &\tabularnewline
\emph{Oecomys flavicans} & & 1 & & & &\tabularnewline
\emph{Oecomys franciscorum} & & 1 & & & &\tabularnewline
\emph{Oecomys mamorae} & & 1 & & & &\tabularnewline
\emph{Oecomys matogrossensis} & & 1 & & & &\tabularnewline
\emph{Oecomys paricola} & & 1 & & & &\tabularnewline
\emph{Oecomys phaeotis} & & 1 & & & &\tabularnewline
\emph{Oecomys rex} & & 1 & & & &\tabularnewline
\emph{Oecomys roberti} & & 1 & & & &\tabularnewline
\emph{Oecomys rutilus} & & 1 & & & &\tabularnewline
\emph{Oecomys speciosus} & & 1 & & & &\tabularnewline
\emph{Oecomys superans} & & 1 & & & &\tabularnewline
\emph{Oecomys sydandersoni} & & 1 & & & &\tabularnewline
\emph{Oecomys tapajinus} & & 1 & & & &\tabularnewline
\emph{Oecomys trinitatis} & & 1 & & & &\tabularnewline
\emph{OLIGORYZOMYS} & 1 & & & & &\tabularnewline
\emph{Oligoryzomys andinus} & & 1 & & & &\tabularnewline
\emph{Oligoryzomys arenalis} & & 1 & & & &\tabularnewline
\emph{Oligoryzomys melanostoma} & & 1 & & & &\tabularnewline
\emph{Oligoryzomys brendae} & & 1 & & & &\tabularnewline
\emph{Oligoryzomys chacoensis} & & 1 & & & &\tabularnewline
\emph{Oligoryzomys costaricensis} & & 1 & & & &\tabularnewline
\emph{Oligoryzomys delicatus} & & 1 & & & &\tabularnewline
\emph{Oligoryzomys destructor} & & 1 & & & &\tabularnewline
\emph{Oligoryzomys flavescens} & & 1 & & & &\tabularnewline
\emph{Oligoryzomys fulvescens} & & 1 & & & &\tabularnewline
\emph{Oligoryzomys griseolus} & & 1 & & & &\tabularnewline
\emph{Oligoryzomys guille} & & 1 & & & &\tabularnewline
\emph{Oligoryzomys longicaudatus} & & 1 & & & &\tabularnewline
\emph{Oligoryzomys mattogrossae} & & 1 & & & &\tabularnewline
\emph{Oligoryzomys messorius} & & 1 & & & &\tabularnewline
\emph{Oligoryzomys microtis} & & 1 & & & &\tabularnewline
\emph{Oligoryzomys moojeni} & & 1 & & & &\tabularnewline
\emph{Oligoryzomys nigripes} & & 1 & & & &\tabularnewline
\emph{Oligoryzomys pachecoi} & & 1 & & & &\tabularnewline
\emph{Oligoryzomys rupestris} & & 1 & & & &\tabularnewline
\emph{Oligoryzomys stramineus} & & 1 & & & &\tabularnewline
\emph{Oligoryzomys utiaritensis} & & 1 & & & &\tabularnewline
\emph{Oligoryzomys vegetus} & & 1 & & & &\tabularnewline
\emph{Oligoryzomys yatesi} & & 1 & & & &\tabularnewline
\emph{OREORYZOMYS} & 1 & & & & &\tabularnewline
\emph{Oreoryzomys balneator} & & 1 & & & &\tabularnewline
\emph{ORYZOMYS} & 1 & & & & 1 &\tabularnewline
\emph{Oryzomys albiventer} & & 1 & & & & 1\tabularnewline
\emph{Oryzomys couesi} & & 1 & & & & 1\tabularnewline
\emph{Oryzomys dimidiatus} & & 1 & & & & 1\tabularnewline
\emph{Oryzomys gorgasi} & & 1 & & & & 1\tabularnewline
\emph{Oryzomys palustris} & & 1 & & & & 1\tabularnewline
\emph{Oryzomys texensis} & & 1 & & & & 1\tabularnewline
\emph{PATTONIMUS} & 1 & & & & &\tabularnewline
\emph{Pattonimus ecominga} & & 1 & & & &\tabularnewline
\emph{Pattonimus musseri} & & 1 & & & &\tabularnewline
\emph{PSEUDORYZOMYS} & 1 & & & & 1 &\tabularnewline
\emph{Pseudoryzomys simplex} & & 1 & & & & 1\tabularnewline
\emph{SCOLOMYS} & 1 & & & & &\tabularnewline
\emph{Scolomys melanops} & & 1 & & & &\tabularnewline
\emph{Scolomys ucayalensis} & & 1 & & & &\tabularnewline
\emph{SIGMODONTOMYS} & 1 & & & & 1 &\tabularnewline
\emph{Sigmodontomys alfari} & & 1 & & & & 1\tabularnewline
\emph{SOORETAMYS} & 1 & & & & &\tabularnewline
\emph{Sooretamys angouya} & & 1 & & & &\tabularnewline
\emph{TANYUROMYS} & 1 & & & & &\tabularnewline
\emph{Tanyuromys aphrastus} & & 1 & & & &\tabularnewline
\emph{Tanyuromys thomasleei} & & 1 & & & &\tabularnewline
\emph{TRANSANDINOMYS} & 1 & & & & &\tabularnewline
\emph{Transandinomys bolivaris} & & 1 & & & &\tabularnewline
\emph{Transandinomys talamancae} & & 1 & & & &\tabularnewline
\emph{ZYGODONTOMYS} & 1 & & & & &\tabularnewline
\emph{Zygodontomys brevicauda} & & 1 & & & &\tabularnewline
\emph{Zygodontomys brunneus} & & 1 & & & &\tabularnewline
PHYLLOTINI & & & & & &\tabularnewline
\emph{ANDALGALOMYS} & 1 & & & & &\tabularnewline
\emph{Andalgalomys olrogi} & & 1 & & & &\tabularnewline
\emph{Andalgalomys pearsoni} & & 1 & & & &\tabularnewline
\emph{AULISCOMYS} & 1 & & & & &\tabularnewline
\emph{Auliscomys boliviensis} & & 1 & & & &\tabularnewline
\emph{Auliscomys pictus} & & 1 & & & &\tabularnewline
\emph{Auliscomys sublimis} & & 1 & & & &\tabularnewline
\emph{CALASSOMYS} & 1 & & & & &\tabularnewline
\emph{Calassomys apicalis} & & 1 & & & &\tabularnewline
\emph{CALOMYS} & 1 & & & & &\tabularnewline
\emph{Calomys achaku} & & 1 & & & &\tabularnewline
\emph{Calomys boliviae} & & 1 & & & &\tabularnewline
\emph{Calomys callidus} & & 1 & & & &\tabularnewline
\emph{Calomys callosus} & & 1 & & & &\tabularnewline
\emph{Calomys cerqueirai} & & 1 & & & &\tabularnewline
\emph{Calomys chinchilico} & & 1 & & & &\tabularnewline
\emph{Calomys expulsus} & & 1 & & & &\tabularnewline
\emph{Calomys fecundus} & & 1 & & & &\tabularnewline
\emph{Calomys frida} & & 1 & & & &\tabularnewline
\emph{Calomys hummelincki} & & 1 & & & &\tabularnewline
\emph{Calomys laucha} & & 1 & & & &\tabularnewline
\emph{Calomys lepidus} & & 1 & & & &\tabularnewline
\emph{Calomys miurus} & & 1 & & & &\tabularnewline
\emph{Calomys musculinus} & & 1 & & & &\tabularnewline
\emph{Calomys sorella} & & 1 & & & &\tabularnewline
\emph{Calomys tener} & & 1 & & & &\tabularnewline
\emph{Calomys tocantinsi} & & 1 & & & &\tabularnewline
\emph{Calomys venustus} & & 1 & & & &\tabularnewline
\emph{ELIGMODONTIA} & 1 & & & & &\tabularnewline
\emph{Eligmodontia bolsonensis} & & 1 & & & &\tabularnewline
\emph{Eligmodontia dunaris} & & 1 & & & &\tabularnewline
\emph{Eligmodontia hirtipes} & & 1 & & & &\tabularnewline
\emph{Eligmodontia moreni} & & 1 & & & &\tabularnewline
\emph{Eligmodontia morgani} & & 1 & & & &\tabularnewline
\emph{Eligmodontia puerulus} & & 1 & & & &\tabularnewline
\emph{Eligmodontia typus} & & 1 & & & &\tabularnewline
\emph{GALENOMYS} & 1 & & & & &\tabularnewline
\emph{Galenomys garleppii} & & 1 & & & &\tabularnewline
\emph{GRAOMYS} & 1 & & & & &\tabularnewline
\emph{Graomys chacoensis} & & 1 & & & &\tabularnewline
\emph{Graomys domorum} & & 1 & & & &\tabularnewline
\emph{Graomys edithae} & & 1 & & & &\tabularnewline
\emph{Graomys griseoflavus} & & 1 & & & &\tabularnewline
\emph{LOXODONTOMYS} & 1 & & & & &\tabularnewline
\emph{Loxodontomys micropus} & & 1 & & & &\tabularnewline
\emph{Loxodontomys pikumche} & & 1 & & & &\tabularnewline
\emph{PHYLLOTIS} & 1 & & & & &\tabularnewline
\emph{Phyllotis alisosiensis} & & 1 & & & &\tabularnewline
\emph{Phyllotis amicus} & & 1 & & & &\tabularnewline
\emph{Phyllotis andium} & & 1 & & & &\tabularnewline
\emph{Phyllotis anitae} & & 1 & & & &\tabularnewline
\emph{Phyllotis bonariensis} & & 1 & & & &\tabularnewline
\emph{Phyllotis camiari} & & 1 & & & &\tabularnewline
\emph{Phyllotis caprinus} & & 1 & & & &\tabularnewline
\emph{Phyllotis darwinii} & & 1 & & & &\tabularnewline
\emph{Phyllotis definitus} & & 1 & & & &\tabularnewline
\emph{Phyllotis gerbillus} & & 1 & & & &\tabularnewline
\emph{Phyllotis haggardi} & & 1 & & & &\tabularnewline
\emph{Phyllotis limatus} & & 1 & & & &\tabularnewline
\emph{Phyllotis limatus} & & 1 & & & &\tabularnewline
\emph{Phyllotis magister} & & 1 & & & &\tabularnewline
\emph{Phyllotis nogalaris} & & 1 & & & &\tabularnewline
\emph{Phyllotis occidens} & & 1 & & & &\tabularnewline
\emph{Phyllotis osgoodi} & & 1 & & & &\tabularnewline
\emph{Phyllotis osilae} & & 1 & & & &\tabularnewline
\emph{Phyllotis pearsoni} & & 1 & & & &\tabularnewline
\emph{Phyllotis pehuenche} & & 1 & & & &\tabularnewline
\emph{Phyllotis rupestris} & & 1 & & & &\tabularnewline
\emph{Phyllotis stenops} & & 1 & & & &\tabularnewline
\emph{Phyllotis tucumanus} & & 1 & & & &\tabularnewline
\emph{Phyllotis vaccarum} & & 1 & & & &\tabularnewline
\emph{Phyllotis xanthopygus} & & 1 & & & &\tabularnewline
\emph{SALINOMYS} & 1 & & & & &\tabularnewline
\emph{Salinomys delicatus} & & 1 & & & &\tabularnewline
\emph{TAPECOMYS} & 1 & & & & &\tabularnewline
\emph{Tapecomys primus} & & 1 & & & &\tabularnewline
\emph{Tapecomys wolffsohni} & & 1 & & & &\tabularnewline
REITHRODONTINI & & & & & &\tabularnewline
\emph{REITHRODON} & 1 & & & & &\tabularnewline
\emph{Reithrodon auritus} & & 1 & & & &\tabularnewline
\emph{Reithrodon caurinus} & & 1 & & & &\tabularnewline
\emph{Reithrodon typicus} & & 1 & & & &\tabularnewline
RHAGOMYINI & & & & & &\tabularnewline
\emph{RHAGOMYS} & 1 & & & & &\tabularnewline
\emph{Rhagomys longilingua} & & 1 & & & &\tabularnewline
\emph{Rhagomys rufescens} & & 1 & & & &\tabularnewline
\emph{Rhagomys septentrionalis} & & 1 & & & &\tabularnewline
THOMASOMYINI & & & & & &\tabularnewline
\emph{AEPEOMYS} & 1 & & & & &\tabularnewline
\emph{Aepeomys lugens} & & 1 & & & &\tabularnewline
\emph{Aepeomys reigi} & & 1 & & & &\tabularnewline
\emph{CHILOMYS} & 1 & & & & &\tabularnewline
\emph{Chilomys carapazi} & & 1 & & & &\tabularnewline
\emph{Chilomys fumeus} & & 1 & & & &\tabularnewline
\emph{Chilomys instans} & & 1 & & & &\tabularnewline
\emph{Chilomys georgeledecii} & & 1 & & & &\tabularnewline
\emph{Chilomys neisi} & & 1 & & & &\tabularnewline
\emph{Chilomys percequilloi} & & 1 & & & &\tabularnewline
\emph{Chilomys weksleri} & & 1 & & & &\tabularnewline
\emph{RHIPIDOMYS} & 1 & & & & &\tabularnewline
\emph{Rhipidomys albujai} & & 1 & & & &\tabularnewline
\emph{Rhipidomys austrinus} & & 1 & & & &\tabularnewline
\emph{Rhipidomys baturiteensis} & & 1 & & & &\tabularnewline
\emph{Rhipidomys bezerrensis} & & 1 & & & &\tabularnewline
\emph{Rhipidomys caracolensis} & & 1 & & & &\tabularnewline
\emph{Rhipidomys cariri} & & 1 & & & &\tabularnewline
\emph{Rhipidomys caucensis} & & 1 & & & &\tabularnewline
\emph{Rhipidomys couesi} & & 1 & & & &\tabularnewline
\emph{Rhipidomys emiliae} & & 1 & & & &\tabularnewline
\emph{Rhipidomys fulviventer} & & 1 & & & &\tabularnewline
\emph{Rhipidomys gardneri} & & 1 & & & &\tabularnewline
\emph{Rhipidomys ipukensis} & & 1 & & & &\tabularnewline
\emph{Rhipidomys itoan} & & 1 & & & &\tabularnewline
\emph{Rhipidomys latimanus} & & 1 & & & &\tabularnewline
\emph{Rhipidomys leucodactylus} & & 1 & & & &\tabularnewline
\emph{Rhipidomys macconnelli} & & 1 & & & &\tabularnewline
\emph{Rhipidomys macrurus} & & 1 & & & &\tabularnewline
\emph{Rhipidomys mastacalis} & & 1 & & & &\tabularnewline
\emph{Rhipidomys modicus} & & 1 & & & &\tabularnewline
\emph{Rhipidomys nitela} & & 1 & & & &\tabularnewline
\emph{Rhipidomys ochoagrateroli} & & 1 & & & &\tabularnewline
\emph{Rhipidomys ochrogaster} & & 1 & & & &\tabularnewline
\emph{Rhipidomys similis} & & 1 & & & &\tabularnewline
\emph{Rhipidomys tenuicauda} & & 1 & & & &\tabularnewline
\emph{Rhipidomys tribei} & & 1 & & & &\tabularnewline
\emph{Rhipidomys venezuelae} & & 1 & & & &\tabularnewline
\emph{Rhipidomys venustus} & & 1 & & & &\tabularnewline
\emph{Rhipidomys wetzeli} & & 1 & & & &\tabularnewline
\emph{THOMASOMYS} & 1 & & & & &\tabularnewline
\emph{Thomasomys andersoni} & & 1 & & & &\tabularnewline
\emph{Thomasomys antoniobracki} & & 1 & & & &\tabularnewline
\emph{Thomasomys apeco} & & 1 & & & &\tabularnewline
\emph{Thomasomys aureus} & & 1 & & & &\tabularnewline
\emph{Thomasomys auricularis} & & 1 & & & &\tabularnewline
\emph{Thomasomys australis} & & 1 & & & &\tabularnewline
\emph{Thomasomys baeops} & & 1 & & & &\tabularnewline
\emph{Thomasomys bombycinus} & & 1 & & & &\tabularnewline
\emph{Thomasomys burneoi} & & 1 & & & &\tabularnewline
\emph{Thomasomys caudivarius} & & 1 & & & &\tabularnewline
\emph{Thomasomys cinereiventer} & & 1 & & & &\tabularnewline
\emph{Thomasomys cinereus} & & 1 & & & &\tabularnewline
\emph{Thomasomys cinnameus} & & 1 & & & &\tabularnewline
\emph{Thomasomys contradictus} & & 1 & & & &\tabularnewline
\emph{Thomasomys daphne} & & 1 & & & &\tabularnewline
\emph{Thomasomys dispar} & & 1 & & & &\tabularnewline
\emph{Thomasomys eleusis} & & 1 & & & &\tabularnewline
\emph{Thomasomys emeritus} & & 1 & & & &\tabularnewline
\emph{Thomasomys erro} & & 1 & & & &\tabularnewline
\emph{Thomasomys fumeus} & & 1 & & & &\tabularnewline
\emph{Thomasomys gracilis} & & 1 & & & &\tabularnewline
\emph{Thomasomys hudsoni} & & 1 & & & &\tabularnewline
\emph{Thomasomys hylophilus} & & 1 & & & &\tabularnewline
\emph{Thomasomys incanus} & & 1 & & & &\tabularnewline
\emph{Thomasomys ischyrus} & & 1 & & & &\tabularnewline
\emph{Thomasomys kalinowskii} & & 1 & & & &\tabularnewline
\emph{Thomasomys ladewi} & & 1 & & & &\tabularnewline
\emph{Thomasomys laniger} & & 1 & & & &\tabularnewline
\emph{Thomasomys macrotis} & & 1 & & & &\tabularnewline
\emph{Thomasomys monochromos} & & 1 & & & &\tabularnewline
\emph{Thomasomys nicefori} & & 1 & & & &\tabularnewline
\emph{Thomasomys niveipes} & & 1 & & & &\tabularnewline
\emph{Thomasomys notatus} & & 1 & & & &\tabularnewline
\emph{Thomasomys onkiro} & & 1 & & & &\tabularnewline
\emph{Thomasomys oreas} & & 1 & & & &\tabularnewline
\emph{Thomasomys paramorum} & & 1 & & & &\tabularnewline
\emph{Thomasomys pardignasi} & & 1 & & & &\tabularnewline
\emph{Thomasomys popayanus} & & 1 & & & &\tabularnewline
\emph{Thomasomys praetor} & & 1 & & & &\tabularnewline
\emph{Thomasomys princeps} & & 1 & & & &\tabularnewline
\emph{Thomasomys pyrrhonotus} & & 1 & & & &\tabularnewline
\emph{Thomasomys rosalinda} & & 1 & & & &\tabularnewline
\emph{Thomasomys salazari} & & 1 & & & &\tabularnewline
\emph{Thomasomys silvestris} & & 1 & & & &\tabularnewline
\emph{Thomasomys taczanowskii} & & 1 & & & &\tabularnewline
\emph{Thomasomys ucucha} & & 1 & & & &\tabularnewline
\emph{Thomasomys vestitus} & & 1 & & & &\tabularnewline
\emph{Thomasomys vulcani} & & 1 & & & &\tabularnewline
WIEDOMYINI & & & & & &\tabularnewline
\emph{JULIOMYS} & 1 & & & & &\tabularnewline
\emph{Juliomys ossitenuis} & & 1 & & & &\tabularnewline
\emph{Juliomys pictipes} & & 1 & & & &\tabularnewline
\emph{Juliomys rimofrons} & & 1 & & & &\tabularnewline
\emph{Juliomys ximenezi} & & 1 & & & &\tabularnewline
\emph{PHAENOMYS} & 1 & & & & &\tabularnewline
\emph{Phaenomys ferrugineus} & & 1 & & & &\tabularnewline
\emph{WIEDOMYS} & 1 & & & & &\tabularnewline
\emph{Wiedomys cerradensis} & & 1 & & & &\tabularnewline
\emph{Wiedomys pyrrhorinos} & & 1 & & & &\tabularnewline
\emph{WILFREDOMYS} & 1 & & & & &\tabularnewline
\emph{Wilfredomys oenax} & & 1 & & & &\tabularnewline
''SIGMODONTALIA'' & & & & & &\tabularnewline
ICHTHYOMYINI & & & & & &\tabularnewline
\emph{ANOTOMYS} & 1 & & 1 & & &\tabularnewline
\emph{Anotomys leander} & & 1 & & 1 & &\tabularnewline
\emph{CHIBCHANOMYS} & 1 & & 1 & & &\tabularnewline
\emph{Chibchanomys trichotis} & & 1 & & 1 & &\tabularnewline
\emph{DAPTOMYS} & 1 & & 1 & & &\tabularnewline
\emph{Daptomys ferreirai} & & 1 & & 1 & &\tabularnewline
\emph{Daptomys mussoi} & & 1 & & 1 & &\tabularnewline
\emph{Daptomys oyapocki} & & 1 & & 1 & &\tabularnewline
\emph{Daptomys peruviensis} & & 1 & & 1 & &\tabularnewline
\emph{Daptomys venezuelae} & & 1 & & 1 & &\tabularnewline
\emph{ICHTHYOMYS} & 1 & & 1 & & &\tabularnewline
\emph{Ichthyomys hydrobates} & & 1 & & 1 & &\tabularnewline
\emph{Ichthyomys orientalis} & & 1 & & 1 & &\tabularnewline
\emph{Ichthyomys pinei} & & 1 & & 1 & &\tabularnewline
\emph{Ichthyomys pittieri} & & 1 & & 1 & &\tabularnewline
\emph{Ichthyomys stolzmanni} & & 1 & & 1 & &\tabularnewline
\emph{Ichthyomys tweedii} & & 1 & & 1 & &\tabularnewline
\emph{NEUSTICOMYS} & 1 & & 1 & & &\tabularnewline
\emph{Neusticomys monticolus} & & 1 & & 1 & &\tabularnewline
\emph{Neusticomys orcesi} & & 1 & & 1 & &\tabularnewline
\emph{Neusticomys vossi} & & 1 & & 1 & &\tabularnewline
\emph{RHEOMYS} & 1 & & 1 & & &\tabularnewline
\emph{Rheomys mexicanus} & & 1 & & 1 & &\tabularnewline
\emph{Rheomys raptor} & & 1 & & 1 & &\tabularnewline
\emph{Rheomys thomasi} & & 1 & & 1 & &\tabularnewline
\emph{Rheomys underwoodi} & & 1 & & 1 & &\tabularnewline
SIGMODONTINI & & & & & &\tabularnewline
\emph{SIGMODON} & 1 & & & & &\tabularnewline
\emph{Sigmodon alleni} & & 1 & & & &\tabularnewline
\emph{Sigmodon alstoni} & & 1 & & & &\tabularnewline
\emph{Sigmodon arizonae} & & 1 & & & &\tabularnewline
\emph{Sigmodon fulviventer} & & 1 & & & &\tabularnewline
\emph{Sigmodon hirsutus} & & 1 & & & &\tabularnewline
\emph{Sigmodon hispidus} & & 1 & & & &\tabularnewline
\emph{Sigmodon inopinatus} & & 1 & & & &\tabularnewline
\emph{Sigmodon leucotis} & & 1 & & & &\tabularnewline
\emph{Sigmodon mascotensis} & & 1 & & & &\tabularnewline
\emph{Sigmodon ochrognathus} & & 1 & & & &\tabularnewline
\emph{Sigmodon peruanus} & & 1 & & & &\tabularnewline
\emph{Sigmodon planifrons} & & 1 & & & &\tabularnewline
\emph{Sigmodon toltecus} & & 1 & & & &\tabularnewline
\emph{Sigmodon zanjonensis} & & 1 & & & &\tabularnewline
\textbf{TOTALS} & \textbf{90} & \textbf{489} & \textbf{10} & \textbf{35}
& \textbf{5} & \textbf{13}\tabularnewline
\textbf{\%} & & & \textbf{11} & \textbf{7} & \textbf{6} &
\textbf{3}\tabularnewline
\bottomrule
\end{longtable}\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/Figure-1/Figure-1}

\end{center}
\end{figure}\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/Figure-2/Figure-2}

\end{center}
\end{figure}

\selectlanguage{english}
\FloatBarrier
\end{document}

