LATE CENOZOIC VERTEBRATES FROM THE SOUTHERN PAMPEAN REGION: SYSTEMATIC AND BIO-CHRONOSTRATIGRAPHIC UPDATE

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Recibido: 30 de marzo de 2016 - Aceptado: 16 de mayo de 2016
Para citar este artículo: Cecilia M. Deschamps and Rodrigo L. Tomassini (2016). Late Cenozoic vertebrates
from the southern Pampean Region: systematic and bio-chronostratigraphic update. En: M. Martínez y D.
Olivera (Eds.), Palinología del Meso-Cenozoico de Argentina - Volumen en homenaje a Mirta Elena Quattrocchio.
Publicación Electrónica de la Asociación Paleontológica Argentina 16 (2): 202–225.
Link a este artículo: http://dx.doi.org/10.5710/PEAPA.16.05.2016.113
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RECONSTRUCTION OF LATE QUATERNARY
MARINE SEQUENCES, TIERRA DEL FUEGO
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Guler, Paolillo & Martz
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Borel, Guler, Navarro & Astini
1Comisión de Investigaciones Científicas (CIC), División Paleontología Vertebrados, Museo de La Plata, Universidad Nacional de La Plata, La Plata, Argentina.
2Instituto Geológico del Sur (INGEOSUR)-Consejo Nacional de Investigaciones Científicas y Técnicas, Departamento de Geología, Universidad Nacional del Sur,
Bahía Blanca, Argentina.
Asociación Paleontológica Argentina
Maipú 645 1º piso, C1006ACG, Buenos Aires
República Argentina
Tel/Fax (54-11) 4326-7563
Web: www.apaleontologica.org.ar
www.peapaleontologica.org.ar
ISSN 2469-0228
LATE CENOZOIC VERTEBRATES FROM THE
SOUTHERNPAMPEAN REGION: SYSTEMATIC
AND BIO-CHRONOSTRATIGRAPHIC UPDATE
CECILIA M. DESCHAMPS1
RODRIGO L. TOMASSINI2

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LATE CENOZOIC VERTEBRATES FROM THE
SOUTHERN PAMPEAN REGION: SYSTEMATIC AND
BIO-CHRONOSTRATIGRAPHIC UPDATE
CECILIA M. DESCHAMPS1ANDRODRIGO L. TOMASSINI2
1Comisión de Investigaciones C ientíficas (CIC), División Paleontología Vertebrados, Museo de La Plata, Universidad N acional de La Plata, La Plata, Argentina.
ceci@fcnym.unlp.edu.ar
2Instituto Geológico del Sur (INGEOSUR)-Consejo Nacional de Investigaciones Científicas y Técnicas, Departamento de Geología, Universidad Nacional del Sur,
Bahía Blanca, Argentina. rodrigo.tomassini@yahoo.com.ar
Abstract.The knowledge of the vertebrate systematics and bio-chronostratigraphy of Late Cenozoic from the southwest of the Buenos Aires
Province is updated. The study is focused on 12 localities that encompass the latest Miocene to the Holocene. Biostratigraphic units were iden-
tified and correlated to those of other areas of the Pampean Region. Farola Monte Hermoso, Bajo San José and Playa del Barco outstand
because they yielded a large amount of fossil remains. In turn, the quarries near Grünbein allowed refining the age of “Huayquerian” faunas
and their relationship with “Montehermosan” ones. The localities Cantera Seminario, Barrancas de Sarmiento, Cantera Vialidad, and Cantera
Relleno Sanitario are assigned to the latest Miocene-earliest Pliocene; Farola Monte Hermoso and Las Oscuras, to the Early Pliocene; Bajo San
José to the Middle Pleistocene; Puesto La Florida, Chacra Santo Domingo, and García del Río to the Late Pleistocene–Holocene; Playa del Barco
to the Late Pleistocene; Pliocene s.l., and Pleistocene–Holocene levels are exposed at Balneario Saldungaray.
Key words. Biostratigraphy. Mammals. Late Miocene–Holocene. Buenos Aires Province. Argentina.
Resumen.VERTEBRADOS DEL CENOZOICO TARDÍO DEL SUDOESTE DE LA REGIÓN PAMPEANA: ACTUALIZACIÓN SISTEMÁTICA Y BIO-
CRONOESTRATIGRÁFICA. Se realiza una actualización del conocimiento de la sistemática de los vertebrados y la bio-cronoestratigrafía
del Cenozoico tardío del sudoeste de la Provincia de Buenos Aires. El trabajo se enfoca en 12 localidades que abarcan desde el Mioceno más
tardío hasta el Holoceno. En ellas se identificaron unidades bioestratigráficas que se correlacionan con otras áreas de la Región Pampeana.
Se destacan Farola Monte Hermoso, Bajo San José y Playa del Barco como las localidades más fosilíferas. Por su parte, las canteras cer-
canas a la localidad de Grünbein se destacan por permitir la aproximación a las edades de faunas “huayquerienses” y su relación con las
“montehermosenses”. Las localidades Cantera Seminario, Barrancas de Sarmiento, Cantera Vialidad y Cantera Relleno Sanitario se asignan
al Mioceno más tardío–Plioceno más temprano; Farola Monte Hermoso y Las Oscuras al Plioceno Temprano; Bajo San José al Pleistoceno
Medio; Puesto La Florida, Chacra Santo Domingo y García del Río al Pleistoceno Tardío–Holoceno; Playa del Barco al Pleistoceno Tardío; en
Balneario Saldungaray afloran niveles asignados al Plioceno s.l. y al Pleistoceno–Holoceno.
Palabras clave. Bioestratigrafía. Mamíferos. Mioceno Tardío–Holoceno. Provincia de Buenos Aires. Argentina.
THE TEMPORAL scheme of the South American Cenozoic was
established in the XIX Century by Ameghino (e.g., Ameghino,
1889, 1898) on the basis of mammal assemblages of Pata-
gonia and central Argentina. Pascual et al. (1965) introduced
the first scheme of South American land-mammal ages
(SALMAs), following the proposal of Ameghino, which was
not substantially modified. The temporal calibration of the
continental Late Miocene–Holocene is based mostly on
mammal faunas from central Argentina. This interval in-
cludes the Chasicoan, Huayquerian, Montehermosan, Cha-
padmalalan, Marplatan, Ensenadan, Bonaerian, Lujanian
and Platan SALMAs and Stages/Ages (Cione and Tonni,
1995, and references therein).
The southwestern Buenos Aires Province represents an
outstanding area to study the biochronology and bios-
tratigraphy of this interval based on the analysis of mam-
mals because it has several outcrops bearing remains of at
least the last 10 My. Some of them were already well known
in the paleontological literature, for example Farola Monte
Hermoso (Darwin, 1846; Bravard, 1857; Ameghino, 1887,
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1889; Frenguelli, 1928, 1950; J.L. Kraglievich, 1946; Leanza,
1948; Bonaparte, 1960; more recently Tonni et al., 1992,
among others), Punta Alta (Darwin, 1846), Playa del Barco
(Ameghino, 1908; L. Kraglievich, 1926, 1934; Frenguelli, 1928;
Cabrera, 1929; J.L. Kraglievich, 1946; Parodi Bustos, 1962;
more recently Aramayo and Manera de Bianco, 1989; To-
massini et al., 2010). However, the idea to undertake in-
vestigations with a multidisciplinary approach began in the
1980s with the initiative of Dr. Mirta Quattrocchio by forming
a team to conduct geo-paleontological researches.
The Laboratory of Palynology of the Universidad Na-
cional del Sur headed by Dr. Quattrocchio was already well
known for the palynological studies in Argentina and
abroad. By those times the staff began to study the profiles
exposed along rivers, creeks, roads and railways cuts in the
area of Bahía Blanca in which Late Cenozoic sediments were
represented. We joined the field work together with paly-
nologists, sedimentologists and specialists in microinverte-
brates that were already part of the team, with the aim of
making our contribution from the point of view of vertebrate
paleontology. The common idea was to make the reconstruc-
tion of the geological and paleoenvironmental evolution of
the area.
During field work, several exposures appropriate for
multidisciplinary study were found. In some of them the
vertebrate record was scarce, but anyway they were sig-
nificant when making the correlation with other localities.
In this way, a wider span of time and geographic area could
be studied.
The first results were limited to specific localities (e.g.,
Quattrocchio et al., 1988; Deschamps and Borromei, 1992;
Deschamps and Tonni, 1992; Verzi and Deschamps, 1996;
Deschamps et al., 1998), but with time, data were used to
make bio-chronostratigraphic proposals (Deschamps, 2003,
2005), which were refined in subsequent papers (e.g., Verzi et
al., 2004a, 2008; Deschamps et al., 2012, 2013; Tomassini,
2012; Tomassini and Montalvo, 2013; Tomassini et al.,
2013a) even making inferences about environmental con-
ditions suggested by the recorded taxa. In this sense, ro-
dents were particularly important among mammals (Verzi
et al., 2004a; Quattrocchio et al., 2008; Deschamps et al.,
2009, 2012, 2013; Tomassini et al., 2013a; Vucetich et al.,
2014a,b, 2015).
The purpose of the present contribution is to provide an
update of both the stratigraphic proposal, and the mammal
systematics on which it is based, for the Late Miocene–
Holocene interval, within an area of the southwest of the
Buenos Aires Province between 38º 20’–39º S, and 61º
35’–62º 10’ W (Fig. 1). In this way, we wish to acknowledge
Dr. Mirta Quattrocchio and to offer this work as a tribute for
the influence she has had on the development of our careers.
GEOLOGICAL SETTING
The oldest sediments bearing vertebrate remains in this
area correspond to the Late Miocene interval and form the
regional substrate above which the present relief was
elaborated (Zárate, 2005). These are massive to coarsely
stratified, brownish red to yellowish sandy silts ending with
a massive carbonate level, known as “Pampean sediments”.
The exposures are generally isolated along the banks of
drainage systems. Different lithostratigraphic units were
named for these sediments (some of them without the re-
Figure 1. Location map showing the studied localities. Grünbein repre-
sents three quarries very close to each other: canteras Seminario,
Vialidad and Relleno Sanitario.

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quirements of the stratigraphic Argentinean code CAE,
1992), e.g., Arroyo Chasicó (Pascual, 1961), Epecuén (Pas-
cual, 1961), Pampiano (Fidalgo et al., 1973), La Norma (De
Francesco, 1992), Irene (Reig, 1955), Saldungaray and La
Toma (Furque, 1967) formations. Folguera and Zárate
(2009, 2011) gathered them as the Cerro Azul Formation
and interpreted that they represent distal sinorogenic fa-
cies that document the Andean tectonic dynamic. Folguera
and Zárate (2009) and Montalvo et al. (2012) proposed an
evolutionary, regional geological model to explain the geo-
graphical distribution and antiquity of the faunal emblages
found in the Cerro Azul Formation (see Verzi, 1999). According
to the fossil content it includes deposits of the Chasicoan
and Huayquerian ages (Fig. 2). The accumulation of these
sediments began after the regression of the Paranense sea,
identified in northeastern Argentina as Paraná and Entre
Ríos formations (sensu Chebli et al., 1999), and Barranca
Final Formation in northeastern Patagonia (Colorado Basin;
Zambrano, 1972). The establishment of these diverse
groups of environments that favored the development of
continental vertebrates was called Edad de las Planicies
Australes (the age of the austral plains) by Pascual and
Bondesio (1982). According to Zárate (2005) there was a
progressive trend towards cooling and aridization, with
alternating wetter and warmer conditions. In most sections
sedimentation was related to fluvial agents or water bodies;
eolian facies were subordinated, although through time they
became dominant.
Pliocene sediments were grouped together with those
Late Miocene ones as the “Araucanense”. They include the
Montehermosan and Chapadmalalan ages. Several expo-
sures, mainly represented by cliffs located in the Atlantic
coast, yielded abundant mammal remains, being the most
significant those of Farola Monte Hermoso and the area of
Mar del Plata-Miramar, which are mostly related to fluvial
environments.
The sedimentary record of the latest Pliocene–Pleistocene
is represented by fluvial and aeolian sequences which are
subject of several stratigraphic proposals in different areas
of the Buenos Aires Province (see Zárate, 2005). Landscape
reactivation occurs with the development of valleys carved
in the Mio–Pliocene substrate. The fluvial Late Pleistocene-
Holocene units are the equivalents to the Luján Formation
of northeastern Buenos Aires Province (Fidalgo et al., 1973):
Agua Blanca Formation (De Francesco, 1992, and modifica-
tions of Rabassa, 1989, and Zavala and Quattrocchio, 2001)
or part of the San José Sequence and Agua Blanca Sequence
(Zavala and Quattrocchio, 2001), as well as the Chacra La
Blanqueada Formation (Rabassa, 1989), the youngest flu-
vial unit, corresponding to overflow sediments. The eolian
sediments of this interval are included in the Saavedra For-
mation (De Francesco, 1992), equivalent to the La Postrera
Formation of eastern Buenos Aires Province (Fidalgo et al.,
1973), and Matadero Saldungaray Formation (Rabassa,
1989), which represents the youngest eolian sediments of
historical times.
Zavala and Quattrocchio (2001) produced a chronos-
tratigraphic chart in which they proposed the relationships
Figure 2. Stratigraphic chart showing the levels exposed at the studied
localities correlated with International and South American ages.

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among the lithostratigraphic units of the Late Cenozoic.
The finding of mammals in many of them (Verzi et al., 2004a,
2008; Deschamps, 2005; Tomassini et al., 2010, 2013a;
Deschamps et al., 2012, 2013) together with numerical
ages (e.g., Aramayo, 1997; Schultz et al., 2006) allowed im-
proving their temporal assignment.
STUDIED LOCALITIES
The localities representing the Late Miocene–Holo-
cene interval selected for this contribution will be listed
according to the age of the exposed sediments from oldest
to youngest. See complete list of taxa in Appendix 1.
Late Miocene–Pliocene
This interval was studied in quarries near Bahía Blanca
and cliffs of the Sauce Grande River and the Atlantic coast.
1) Cantera Seminario
Location: 38º 44’ 08’’ S, 62º 12’ 19’’ W; 58–68 m height (see
Grünbein in Figs. 1, 3.1).
Bearing unit: Cerro Azul Formation (sensu Folguera and
Zárate, 2009). The section is 11 m thick and was divided into
five levels. Fossils were found in the upper part of level 2,
below the calcrete crust.
Biostratigraphic units recognized in the sequence: type section
of the Xenodontomys ellipticus Zone (Verzi et al., 2008).
Age: Late Huayquerian (Late Miocene–earliest Pliocene; late
Messinian–early Zanclean; see below; Deschamps et al.,
2013).
Fossil content: the octodontid rodents Xenodontomys ellipti-
cus and Phtoramys cf. P. hidalguense are important biostrati-
graphic indicators (see Deschamps et al., 1998; Deschamps,
2005; Verzi et al., 2008 for details). Other taxa include:
Doellotatus cf. D. inornatus, D. cf. D. praecursor, Chorobates
sp., Paedotherium cf. P. minor, Tremacyllus cf. T. impressus,
Orthomyctera sp., cf. Palaeocavia) and Lagostomus sp. (we
follow Rasia, 2016 for the validity of “Lagostomopsis”) (Fig. 4).
2) Barrancas de Sarmiento
Location: 38º 42’ 05’’ S, 62º 15’ 51’’ W; 50 m height (Figs. 1,
3.2).
Bearing unit: Cerro Azul Formation (sensu Folguera and
Zárate, 2009).
Biostratigraphic units recognized in the sequence: Xenodonto-
mys ellipticus Zone (Verzi et al., 2008).
Age: Late Huayquerian (Late Miocene–earliest Pliocene; late
Messinian–early Zanclean; see below; Deschamps et al.,
2013).
Fossil content: Xenodontomys ellipticus is an important bios-
tratigraphic indicator (see Verzi and Deschamps, 1996;
Deschamps, 2005; Verzi et al., 2008 for details). Other taxa:
Paedotherium bonaerense, Lagostomus sp., ?Palaeocavia, and
Eutatini indet. (Fig. 5)
3) Cantera Vialidad
Location: 38º 45’ 19.89’’ S, 62º 09’ 39.75’’ W; 51–64 m
height (see Grünbein in Fig. 1, 3.3).
Bearing unit: Cerro Azul Formation (sensu Folguera and
Zárate, 2009).
Biostratigraphic units recognized in the sequence: Xenodonto-
mys ellipticus Zone (Verzi et al., 2008).
Age: Late Huayquerian (Late Miocene–earliest Pliocene; late
Messinian–early Zanclean; see below; Deschamps et al.,
2013). This deposit has a numerical dating of 5.28±0.04 Ma
(Schultz et al., 2006).
Fossil content: Xenodontomys ellipticus is an important bios-
tratigraphic indicator which allows correlations with Ba-
rrancas de Sarmiento and Cantera Seminario. Remains of
this rodent were found in the same level of the dating, and
also in overlying levels (Deschamps et al., 2013; Deschamps
and Tomassini, personal observations). Other unpublished
taxa include Paedotherium sp., and Chorobates villosissimus.
4) Cantera Relleno Sanitario
Location: 38º 46’ 24’’ S, 62º 09’ 25’’ W; 12–24 m height (see
Grünbein in Figs. 1, 3.4.)
Bearing unit: Cerro Azul Formation (sensu Folguera and
Zárate, 2009). This section has 8 m mean thickness divided
into five levels on the basis of calcrete crusts and paleosoils.
Materials were recovered from two levels at the middle of
the exposure.
Biostratigraphic units recognized in the sequence: Xenodon-
tomys ellipticus Zone (Verzi et al., 2008) because of the
presence of Phtoramys cf. P. hidalguense.
Age: Late Huayquerian (Late Miocene–earliest Pliocene; late
Messinian–early Zanclean; see below; Deschamps et al.,
2013).
Fossil content: From the lower Level 1 (paleosoil): cf. Borh-
yaenidium Phtoramys cf. P. hidalguense, Macrochorobates sp.,
Promacrauchenia sp.; Level 2 (calcrete level overlying the pa-

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leosoil): Chasicotatus cf. C. peiranoi, Chorobates villosissimus,
Macroeuphractus cf. M. morenoi, cf. Aspidocalyptus, cf.
Berthawyleria, Paedotherium cf. P. minor, Tremacyllus cf. T. im-
presus, and Promacrauchenia sp. (Fig. 6).
Figure 3. View of the exposures at the studied localities. 1, Cantera Seminario; 2, Barrancas de Sarmiento; 3, Cantera Vialidad; 4, Cantera Re-
lleno Sanitario; 5, Farola Monte Hermoso; 6, Las Oscuras; 7, Balneario Saldungaray; 8, Bajo San José; 9, Puesto La Florida; 10, Chacra Santo
Domingo; 11, García del Río; 12, Playa del Barco.

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5) Farola Monte Hermoso
Location: 38º 58’ 01’’ S, 61º 41’ 43’’ W; 0–10 m height (Figs.
1, 3.5).
Bearing unit: Monte Hermoso Formation (Zavala, 1993).
Biostratigraphic units recognized in the sequence: type sec-
tion of the Eumysops laeviplicatus Range Zone (Tomassini
et al., 2013a).
Age: Montehermosan (Early Pliocene; Zanclean; Tomassini
et al., 2013a).
Fossil content: Eumysops laeviplicatus, Eumysops formosus,
Eucelophorus cabrerai, Pithanotomys columnaris, Phugathe-
rium cataclisticum are important biostratigraphic indicators
(Deschamps et al., 2012, 2013; Tomassini et al., 2013a).
Other frequent taxa include Actenomys priscus, Paramyocas-
tor diligens (see Verzi et al., 2002), Paedotherium bonaerense,
Paedotherium typicum, Tremacyllus impressus, Doellotatus
inornatus, Eoauchenia primitiva, Pseudotypotherium sp. and
Plohophorus figuratus (Fig. 7). See complete list in Appendix 1.
Recently, the knowledge of this fauna has been greatly
increased with systematic, taphonomic, paleoenviron-
mental and paleobiogeographic contributions (e.g., Zurita
and Tomassini, 2006; Albino et al., 2009; Tomassini and
Montalvo, 2010, 2013; Miño-Boilini et al., 2011; Tomassini
et al., 2011, 2014a; Agnolin and Tomassini, 2012; Agnolin
et al., 2014).
Figure 4. Mammals found in Cantera Seminario. 1, osteoderm of
Doellotatus cf. D. inornatus; 2, two osteoderms of Doellotatus cf. D.
praecursor; 3, fragment of left mandible of Lagostomus sp.; 4, frag-
ment of right mandible of Phtoramys cf. P. hidalguense; 5, skull frag-
ment of Orthomyctera sp.; 6, skull and left mandible fragments of
Xenodontomys ellipticus.Anterior to the right (3,4) and to top (5,6).
Scale= 1 cm (1, 2), 5 cm (3), 5 mm (4–6).
Figure 5. Mammals found in Barrancas de Sarmiento. 1, skull frag-
ment and right mandible of Xenodontomys ellipticus; 2, skull fragment
of Paedotherium bonaerense. Anterior to the right (1) and to top (2).
Scales= 4 mm (1) and 1 cm (2).
Figure 6. Some of the specimens found in Cantera Relleno Sanitario.
1, mandible fragment of cf. Borhyaenidium; 2, mandible fragment of
Phto ramys cf. P. hidalgu ense ; 3, osteoderms of Aspido calyptus sp.;
4, carapace fragment of cf. Berthawyleria; 5, osteoderms of Macro-
euphractus cf. M. morenoi; 6, osteoderms of Chasicotatus sp.; 7, palate
fragment of Promacrauchenia sp. Anterior to left (2) and to the right
(7). Scales= 1 cm (1–6), 5 cm (7).

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Figure 7. Some of the mammals found in Farola Monte Hermoso. 1, left mandible fragment of Hyperdidelphys inexpectata (inverted); 2, skull
fragment in ventral view of Pseudotypotherium sp.; 3, skull in ventral view of Toxodon chapalmalensis; 4, skull fragment in ventral view of
Paedotherium bonaerense; 5–9, right mandible fragments and detail of dental series in occlusal view of: 5, Neophanomys sp.; 6, Actenomys
priscus;7,Pithanotomys columnaris;8,Palaeocavia sp.; 9, Eumysops laeviplicatus; 10, left mandible fragment and detail of dental series in
occlusal view (inverted) of Paramyocastor diligens; 11, skull fragment of Phugatherium cataclisticum.Anterior to right (1, 5–11) and to top (2–4).
Scales= 5 mm (A, E-J), 1 cm (B, D), 10 cm (C), and 2 cm (K).

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According to Tomassini et al. (2013a) this biostratigraphic
unit represents a brief lapse, included within a temporal
range whose approximate boundaries are <5.28 Ma and
4.5/5.0 Ma.
6) Las Oscuras
Location: 38º 44’ 48.55’’ S, 61º 44’ 01.04’’ W; 82 m height
(Fig. 1, 3.6).
Bear ing un it: Saldungaray-La Toma formations (sensu
Deschamps, 2005); Cerro Azul Formation (sensu Folguera
and Zárate, 2009).
Biostratigraphic units recognized in the sequence: Actenomys
priscus-Plohophorus cuneiformis Zone (Deschamps, 2005).
This unit may correspond to the Eumysops laeviplicatus
Range Zone defined in Farola Monte Hermoso (see dis-
cussion in Tomassini et al., 2013a).
Age: Montehermosan (Early Pliocene; Zanclean; sensu
Deschamps, 2005).
Fossil content: Actenomys priscus, Plohophorus cuneiformis,
Pseudotypotherium sp., Lagostomus sp., Orthomyctera sp.,
Dolicavia sp., and Epitherium laternarium (Deschamps et al.,
1989; Deschamps, 2005).
The record of Actenomys priscus, with similar characteristics
to the specimens recovered from Farola Monte Hermoso,
plus the absence of the different species of Xenodontomys,
support the proposed age.
Pleistocene–Holocene
This interval was studied in the banks of the Sauce
Grande River and Napostá Grande Creek.
7) Sauce Grande River valley
a-Balneario Saldungaray
Location: 38º 11’ 52.30’’ S, 61º 46’ 11.39’’ W; 20 m height
(Figs. 1, 3.7).
Bearing unit: The sequence begins with deposits of the Sal-
dungaray Formation at the water level. This unit is overlain
by coarse conglomerates and sands of the lower and upper
sections of the San José Sequence (Zavala and Quattrocchio,
2001). Rabassa (1989) assigned these two latter units to
the Agua Blanca Formation on the basis of two radiocarbon
datings (32,300 +/- 1,800 RCYBP; Figini et al., 1989; 27,500
+/- 670 RCYBP; Figini et al., 1989; Rabassa, 1989) but geo-
morphology and stratigraphic position suggest an older age
for these units. The profile ends with eolian deposits of the
Matadero Saldungaray Formation.
Biostratigraphic units recognized in the sequence: The recorded
taxa were insufficient to recognize any unit.
Age: Pliocene s.l. (Saldungaray Formation), Middle Pleisto-
cene (San José Sequence according to Zavala and Quattro-
cchio, 2001 and Deschamps, 2005), or Late Pleistocene
Agua Blanca Formation (according to Rabassa, 1989), His-
torical times–Present (Matadero Saldungaray Formation).
Fossil content: Mammal remains were very scarce. Saldun-
garay Formation: Paedotherium bonaerense; San José Se-
quence, lower section: Glossotherium sp. and Lama sp.; upper
section Lagostomus sp.; Matadero Saldungaray Formation:
Ctenomys talarum and Lepus europaeus.
b-Bajo San José
Location: 38º 29’ 12.10’’ S, 61º 46’ 59.60’’ W; 125 m height
(Figs. 1, 3.8).
Bearing unit: San José Sequence (Zavala and Quattrocchio,
2001), especially a sandy lens up to 1 m thick of the lower
section that yielded most of the small vertebrates, 2 m from
the base of the profile.
Biostratigraphic units recognized in the sequence: type section
of the Ctenomys kraglievichi Zone (Verzi et al., 2004a). The
zone was also recognized at Las Grutas-Punta Negra in
Necochea (southeastern Buenos Aires Province), as well
as in Camet and Constitución, in the cliffs north of Mar del
Plata.
Age: Bonaerian (Middle Pleistocene; Verzi et al., 2004a)
Fossil content: the ctenomyid rodent Ctenomys kraglievichi
as well as the dasypodid Tolypeutes sp. nov. (Scillato-Yané in
Deschamps, 2005) are important biostratigraphic indicators,
exclusive of the Bonaerian. Other taxa include: Pisces (Pi-
melodella aff. P. laticeps, Callichthys callichthys, Percichthys
sp., Corydoras cf. C. paleatus), turtles (Hydromedusa tectifera),
birds (Rhea sp., Chloephaga sp. 1, Chloephaga sp. 2, Porphyrio
sp., cf. Pseudoseisura cursor-Pseudoseisuropsis nehuen, Mo-
tacillinae indet.), marsupials (Lestodelphys sp.), dasypodids
(Chaetophractus villosus, Zaedyus pichiy, Eutatus seguini, Pro-
praopus sp.), glyptodontids (Glyptodon clavipes, Doedicurus
sp., Panochthus tuberculatus, Sclerocalyptus cf. S. ornatus),
sloths (Scelidotherium cf. S. leptocephalum, Glossotherium
sp., Lestodon armatus, Megatherium americanum), litopterns
(?Macraucheniopsis ensenadensis), notoungulates (Toxodon
sp.), cricetid rodents (Akodon cf. A. azarae, Akodon cf. A. inisca-

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DESCHAMPS AND TOMASSINI: LATE CENOZOIC VERTEBRATES FROM SOUTHERN PAMPEAN REGION
tus, Oxymycterus sp., Reithrodon auritus, Phyllotis sp., Lun-
domys sp.), caviomorph rodents (Microcavia sp., Galea sp.,
Lagostomus sp., Neochoerus cf. N. tarijensis, Myocastor colum-
naris), Gomphotheriidae indet., artiodactyls (Tayassuinae
indet., Lama sp., Cervidae indet.), perissodactyls (Hippidion
principale), and carnivores (Pseudalopex sp., cf. Herpailurus)
(Fig. 8). See complete list in Appendix 1.
The oldest records of Callichthys callichthys, Percichthys,
Porphyrio, Herpailurus, Lundomys, Oxymycterus, Phyllotis, and
Tayassuinae (Cione and López Arbarello, 1995; Pardiñas and
Deschamps, 1996; Prevosti, 2006; Pardiñas and Teta, 2011;
Gasparini, 2013) come from this site.
Some taxa are significant from a biogeographic point of
view. Among Osteichthyes, the pimelodid siluriformes
Pimelodella, Callichthys and Corydoras, and the Percichthy-
dae Percichthys are not simpatric today. The southern border
of the geographic distribution of Callichthys is currently
farther north within the Buenos Aires Province, and on the
contrary, Percichthys inhabits today the Austral Subregion
(Cione and López Arbarello, 1995). This is the southernmost
record of the turtle Hydromedu sa tectife ra which today
inhabits the Neotropical Region up to northern Argentina
(de la Fuente, 1992, 1999).
As well, other taxa are important in view of their paleo-
environmental meaning (for details see Pardiñas and
Deschamps, 1996; Deschamps, 1998; Deschamps et al.,
2000; Verzi et al., 2004a; Deschamps, 2005; Prevosti, 2006;
Pardiñas and Teta, 2011; Gasparini, 2013).
The birds record is outstanding because three orders are
represented, Anseriformes, Gruiformes and Passeriformes
(Tonni and Deschamps, 2001). Anseriformes, Family Anati-
dae, include several remains of small indeterminate anatids
and Chloephaga. This genus would be represented by two
new species. Gruiformes is represented by the Family
Rallidae, genus Porphyrio. Passeriformes are recorded by a
large furnariid similar to Pseudoseisura cursor and Pseudo-
seisuropsis nehuen (both from the Ensenadan of the Buenos
Aires Province; Tonni and Noriega, 2001) and an indetermi-
nate passeriid of the Family Motacillinae. Modern Pseudo-
seisura are widely distributed in South America inhabiting
arid environments, but both species of Porphyrio inhabit
intertropical South America. This means that Porphyrio
would join Callichthys, Hydromedusa and Lundomys in warm
and humid environments, and Chloephaga would join Perci-
chthys, Lestodelphys, Phyllotis and Akodon iniscatus among
the taxa adapted to more arid and/or colder environments.
c-Puesto La Florida
Location: 38º 35’ S, 61º 45’ W; 108 m height. This site is lo-
cated at the Sauce Grande River valley between Bajo San
José and Las Oscuras localities (Fig. 1, 3.9).
Bearing unit: middle and upper sections of the Agua Blanca
Sequence, Chacra La Blanqueada and Matadero Saldun-
garay formations (Zavala and Quattrocchio, 2001).
Biostratigraphic units recognized in the sequence: type section
of the Ozotoceros bezoarticus Zone in the upper section of
the Agua Blanca Sequence, and Bos taurus-Ovis aries Zone
in upper levels of the Chacra La Blanqueada and Matadero
Saldungaray formations (Deschamps, 2005).
Age: Lujanian (Late Pleistocene–Early Holocene) for the
Middle Section of the Agua Blanca Sequence; Platan (Late
Holocene) for the Upper Section of the Agua Blanca Se-
quence; Platan (Late Holocene)–Present for the Chacra La
Blanqueada Formation at this site; historical times–present
for the Matadero Saldungaray Formation (Deschamps,
2005). In the cliffs of the Sauce Grande River near Bajo San
José, Borromei (1995) reported radiocarbon datings for the
upper section of the Agua Blanca Sequence (5010±120 years
14C BP) and Chacra la Blanqueada Formation (2830±90
years 14C BP) which restrict the age to the Middle and Late
Holocene respectively. The Chacra La Blanqueada Forma-
tion was also dated on peat wood samples between 1570 ±
70 and 900±50 years 14C BP at La Toma locality (Rabassa,
1989; Rabassa et al., 1991).
Fossil content: Middle section of the Agua Blanca Sequence:
Lama guanicoe. Upper section of the Agua Blanca Sequence:
Rhea americana, cf. Anas, Chaetophractus villosus, Zaedyus
pichiy, Cavia aperea, and Ozotoceros bezoarticus. Chacra La
Blanqueada and Matadero Saldungaray formations: Bos
taurus.
8) Napostá Grande Creek valley
a-Chacra Santo Domingo
Location: 38º 33’ 45.14’’ S, 62º 04’ 17.27’’ W; 98 m height.
This site is in the middle valley of the Napostá Grande Creek;
access from Bahía Blanca City is through the road known as
La Carrindanga (Figs. 1, 3.10).
Bearing unit: middle and upper sections of the Agua Blanca

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DESCHAMPS AND TOMASSINI: LATE CENOZOIC VERTEBRATES FROM SOUTHERN PAMPEAN REGION
Sequence, Chacra La Blanqueada and Matadero Saldun-
garay formations (Zavala and Quattrocchio, 2001).
Biostratigraphic units recognized in the sequence: type sec-
tion of the Equus (Amerhippus)neogaeus-Macrauchenia pata-
chonica Zone, in the middle section of the Agua Blanca
Sequence (Deschamps, 2005), and type section of the Bos
taurus-Ovis aries Zone in the Matadero Saldungaray Forma-
tion.
Age: Lujanian (Late Pleistocene–Early Holocene) for the
Middle Section of the Agua Blanca Sequence; Platan (Late
Holocene) for the Upper Section of the Agua Blanca Se-
quence (this unit yielded neospecies and a radiocarbon
dating of 1960±100 14C years BP; see Deschamps and
Tonni, 1992); Platan (Late Holocene) for the Chacra La
Blanqueada Formation at this site; historical times for the
Matadero Saldungaray Formation (Deschamps, 2005).
Fossil content: Middle Section of the Agua Blanca Sequence:
scarce remains of Rheidae indet., Chaetophractus villosus,
Scelidotherium leptocephalum, Macrauchenia patachonica,
Lama guanicoe, Lamini indet., and Equus (A.) neogaeus. The
Upper Section yielded abundant remains, especially the
lower levels: Cyprinodontiformes indet., Anura indet., Rhea
sp., Nothura darwini, Tinamidae indet., Anas cf. A. platalea,
Dendrocygna sp., and Anatidae indet., Lestodelphys halli, Thy-
lamys cf. T. pusillus, Chaetophractus villosus, Zaedyus pichiy,
Holochilus brasiliensis, Calomys cf. C. laucha-musculinus, Rei-
throdon auritus, Ctenomys sp., Cavia aperea, Lama guanicoe,
Ozotoceros bezoarticus, and Pseudalopex aff. P. gymnocercus).
Chacra La Blanqueada Formation: Ctenomys talarum and
Lama guanicoe. Matadero Saldungaray Formation: Lama gua-
nicoe and Bos taurus (Fig. 9).
b-García del Río
Location: 38º 21’ 49.70’’ S, 62º 09’ 05.32’’ W, 184 m height.
Upstream of Napostá Grande village in the Napostá Grande
Creek (Figs. 1, 3.11).
Bearing units: Middle and upper sections of the Agua Blanca
Sequence, Chacra La Blanqueada and Matadero Saldun-
garay formations (Zavala and Quattrocchio, 2001).
Biostratigraphic units recognized in the sequence: the recorded
taxa were insufficient to recognize any unit.
Age: the Upper Section of the Agua Blanca Sequence has a
radiocarbon dating of 2610±60 years 14C BP (Quattrocchio
et al., 1998), Late Holocene. Chacra La Blanqueada has a ra-
diocarbon dating in this locality of 2342±47 years 14 C BP
(Tomassini et al., 2014b), Late Holocene.
Fossil content: Lama guanicoe was recorded in all units
(Deschamps, 2005). Also, in Chacra La Blanqueada Forma-
tion Ctenomys cf. C. talarum, Cavia aperea, and Chaetophrac-
tus villosus were recovered (Tomassini et al., 2014b).
10) Playa del Barco
Location: 39º 00’ 09’’ S, 61º 34’ 52’’W; 0–2 m height (Figs. 1,
3.12).
Bearing unit: San José Sequence (Zavala and Quattrocchio,
2001).
Biostratigraphic units recognized in the sequence: Equus
(Amerhippus) neogeus-Macrauchenia patachonica Zone (De-
schamps, 2005).
Age: Lujanian (Late Pleistocene–Early Holocene). A radio-
carbonic dating yielded an age of 16.440±320 14 C years
BF (Aramayo, 1997). Some levels could include Bonaerian
(Middle Pleistocene) fauna (see Zavala and Quattrocchio,
2001; Tomassini et al., 2010).
Fossil content: Equus (Amerhippus) neogeus, Macrauchenia
patachonica, Glyptodon reticulatus, Doedicurus clavicaudatus,
Figure 8. Some of the specimens found in Bajo San José. 1–7, Aves. 1, tarsus-metatarsus of Rhea sp.; 2–3, Chloephaga sp. 1; 2, left femur; 3,
left tarsus-metatarsus; 4–5, Chloephaga sp. 2; 4, right humerus; 5, proximal fragment of left humerus; 6, right humerus of Motacillinae indet.;
7, left coracoid of cf. Pseudoseisura-Pseudoseisuropsis; 8–13, Rodentia. 8, upper molars of Lundomys sp.; 9, right mandible (inverted) of Akodon
cf. A. iniscatus; 10, skull of Ctenomys kraglievichi; 11, palate fragment of Myocastor columnaris; 12, right mandible of Lagostomus sp.; 13, skull
of Neochoerus cf. N. tarijensis; 14–15, mandibles of Carnivora. 14, Pseudalopex sp.; 15, cf. Herpailurus; 16–20, Edentata. 16, carapace frag-
ment of Glyptodon clavipes; 17, osteoderm of Tolypeutes sp. nov.; 18, osteoderm of Eutatus seguini; 19, osteoderm of Zaedyus pichiy; 20, right
mandible fragment of Megatherium americanum; 21, left posterior autopodium of ?Macraucheniopsis ensenadensis; 22, 3rd left lower incisor
fragment of Toxodon sp.; 23, molariforms of Hippidion principale; 24, mandible fragment with incisor of Tayassuinae indet.; 25, molar of Gom-
photheriidae indet. Anterior to the right (8–10, 12–15, 24), to top (11), and to the left (20). Scale= 1 cm (2–7, 10–12, 14–15, 17–19), 1 mm
(8), 5 mm (9), 5 cm (1, 13, 21–23), 10 cm (16, 25).

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Eutatus seguini, Scelidotherium leptocephalum, Lestodon ar-
matus, Toxodon platensis, Notiomastodon platensis, Morenela-
phus bonaerense, Hippidion sp., Smilodon populator,
Neochoerus cf. N. tarijensis, among others (Fig. 10; see com-
plete list in Appendix 1).
SYSTEMATIC, BIOCHRONOSTRATIGRAPHIC AND
PALEOENVIRONMENTAL COMMENTS
As mentioned above, since the idea of Mirta Quattrocchio
of facing multidisciplinary studies, paleontologic survey in
southwestern Buenos Aires Province was increased, and is
still increasing today. This was reflected directly in enlarged
collections which in turn allowed improving the knowledge
of the vertebrate communities that inhabited the area
during the last 10 My. In this context, those localities in
which units formed by fluvial deposits are exposed (e.g.,
Farola Monte Hermoso, Bajo San José, Playa del Barco),
yielded the largest amounts and diversity of bone remains.
Together with pollen and ostracodes analyses, vertebrate
taxa helped inferring paleoenvironmental, paleoclimatic and
paleobiogeographic conditions both in the Mio–Pliocene
and Quaternary.
The age of the late Cenozoic continental deposits and
the included fauna is a major issue. Given the scarcity of nu-
merical dating, the age has been almost always determined
on the basis of fossil distribution, which makes boundaries
and temporal extension of biostratigraphic units at least un-
certain and controversial (see Cione and Tonni, 1995, 2005;
Verzi et al., 2008; Deschamps et al., 2013). Multidisciplinary
studies accomplished in the last years, including detailed
fieldwork, paleontological prospection with precise data of
stratigraphic provenance, systematics, sedimentological
analyses, sequential stratigraphy, taphonomy, magne-
tostratigraphy, among others, resulted in an improvement
of biochronostratigraphic schemes.
One of the main advances in this regard is the inference
of the age of “Huayquerian” and “Montehermosan” faunas.
Among mammal faunas, rodents are very useful as bios-
tratigraphic tools because of their wide geographic distri-
Figure 9. Some of the specimens found in Chacra Santo Domingo,
Napostá Grande Creek. 1, Aves, right humerus of Anas cf. A. platalea;
2, tibia-fibula of Bufonidae indet.; 3, left mandible of Lestodelphys
halli; 4, fragments of skull and mandible of Reithrodon auritus; 5, right
mandible of Holochilus brasiliensis (inverted); 6, mandible of Cteno-
mys sp.; 7, osteoderms of Chaetophractus villosus; 8, osteoderm of
Zaedyus pichiy; 9, p4 of Pseudalopex aff. P. gymnocercus.Anterior to
the right (3–4, 6) and to the left (5). Scales= 1 cm (1–8) and 5 mm
(9).
Figure 10. Some of the specimens found in Playa del Barco. 1, skull of
Eutatus seguini; 2, fragment of right maxilla of Toxodon platensis; 3,
left hemimandible of Cervidae indet.; 4, fragment of skull of Morenela-
phus sp.; 5, fragment of right hemimandible of Notiomastodon sp.
Anterior to the right. Scales= 5 cm (1–3), 10 cm (4–5).

bution, and high reproductive and rapid evolutionary rates
(Vianey-Liaud et al., 2011). The knowledge of the systematics
and phylogeny of several groups of rodents recorded in
these intervals has been largely improved in recent years
(e.g., Octodontidae, Ctenomyidae, Echimyidae, Hydrochoeri-
dae). This turned out to be quite significant because many of
them are good biostratigraphic indicators (Vucetich et al.,
2005; Verzi, 2008 and literature therein; Olivares 2009;
Olivares et al., 2012; Deschamps et al., 2013 and literature
therein).
In the study area, “Huayquerian” faunas were found in
Cantera Seminario, Cantera Relleno Sanitario, Cantera Via-
lidad, and Barrancas de Sarmiento. These localities have
in common the record of Xenodontomys ellipticus which is
an octodontid rodent that pertains to the Chas ichimys-
Xenodontomys lineage. The polarity shown by their anage-
netic evolutionary pattern led Verzi et al. (2004b) to propose
that X. ellipticus is younger than X. simpsoni (from Los Sali-
trales Formation, Buenos Aires Province, and several lo-
calities of the Cerro Azul Formation in La Pampa Province)
and older than X. elongatus (found in the Cerro Azul Forma-
tion cropping out at Caleufú, La Pampa Province). It is note-
worthy that two other lineages of octodontid rodents
(Neophanomys and Reigechimys; Verzi et al., 2011; Sostillo
et al., 2014) support the scheme based on the lineage of
Xenodontomys. The trend toward increasing hypsodonty
observed in the lineage of Xenodontomys and in other
caviomorph rodents is related to adaptations to open envi-
ronments within the climatic deterioration of the Late
Miocene (Verzi, 2001). Given that Cantera Vialidad yielded
remains of Xenodontomys ellipticus in the same levels and
above those which have a numerical dating of 5.28±0.04
Ma (Schultz et al., 2006) it may be concluded that “Huay-
querian” faunas in this area are latest Miocene–earliest
Pliocene in age.
On the other hand, “Montehermosan” faunas were found
in Farola Monte Hermoso and Las Oscuras. Deposits of the
Monte Hermoso Formation in its type locality Farola Monte
Hermoso were accumulated in a dynamic fluvial environ-
ment of high-sinuosity rivers (“muddy fine-grained rivers”
in Miall, 1985). In these localities, none of the species of
Xenodontomys has been recorded, being instead abundant
Actenomys priscus, the most derived representative of the
lineage Xenodontomys–Actenomys (Verzi, 2008). In addition,
when these specimens are compared to specimens of A.
priscus found in levels assigned to the Chapadmalalan (from
the area of Mar del Plata-Miramar), the latter display a more
derived dental morphology (Deschamps, 2003; Tomassini
et al., 2013a). Preliminary observations (Tomassini, 2012)
showed that the specimens of Neophanomys found in
Farola Monte Hermoso are also more derived than the
species recognized for the Huayquerian Stage/Age of La
Pampa (N. pristinus and N. recens), Catamarca (N. biplicatus)
and Mendoza (N. biplicatus). Hence the Montehermosan
assemblages cannot be older than Early Pliocene because
the evolutionary stage of these octodontids (and also other
groups of mammals; see Tomassini, 2012; Deschamps et
al., 2012; Tomassini et al, 2013a) supports the idea that the
bearing sediments of the Monte Hermoso Formation are
younger than those of the Cerro Azul Formation at Caleufú
with “Huayquerian” fauna.
Another group of rodents found in the area that turned
out to be very indicative from a biochronologic point of
view are the giant capybaras. The study of the dental evo-
lution of this family resulted in a new interpretation of their
taxonomy and systematics which involved the ontogenetic
change (Vucetich et al., 2005, 2014a,b, 2015; Deschamps
et al., 2007, 2009, 2013). Currently, a single taxon is recog-
nized for each level, and although they were not found in a
single stratigraphic sequence to test the proposal, the
accompanying fauna supports the different age inferred for
each taxon. In “Huayquerian” assemblages only the genus
Cardiatherium, with different species, is recorded (Vucetich
et al., 2005; 2014b). Instead in “Montehermosan” and
“Chapadmalalan” assemblages, Phugatherium is recorded,
with two species in the study area, P. cataclisticum in Farola
Monte Hermoso and P. novum in the area of Mar del Plata-
Miramar (Deschamps et al., 2012, 2013). Capybaras were
one of the keys to suggest that a single biostratigraphic
unit could be determined in the Monte Hermoso Forma-
tion at Farola Monte Hermoso, different form the one
recognized in the area of Mar del Plata-Miramar. This is
supported by other rodent lineages such as the different
species of the echimyid rodent Eumysops (Olivares et al.,
2012) found in these localities (Deschamps et al., 2012;
Tomassini et al., 2013a).
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DESCHAMPS AND TOMASSINI: LATE CENOZOIC VERTEBRATES FROM SOUTHERN PAMPEAN REGION

Concerning the age of the assemblages, the determina-
tion of the extension and the boundaries of the represented
Stage/Age or SALMA has been long debated, especially
those between Huayquerian and Montehermosan. A com-
mon use is to extend the boundaries of the different bios-
tratigraphic units represented in a certain interval in order
to obtain a continuous sequence, even without numerical
dating or faunistic record that support these interpreta-
tions. In recent years, taphonomic and sedimentological
studies carried out in several localities of the Pampean Re-
gion suggested that most assemblages actually represent
a very short interval (e.g., Arroyo Chasicó, Laguna Chillhué,
Caleufú, Farola Monte Hermoso among others; Tomassini
and Montalvo, 2013; Tomassini et al., 2013a,b). We suggest
restricting the assemblage duration to the represented in-
terval, considering the existence of hiatuses between the
following or previous assemblages instead of extending
the duration up to the contiguous unit. In this sense, the
assemblages would be like temporal windows in the strati-
graphic column, which only show the moment of the assem-
blage, being the rest hidden. Their relative chronology, and
partly the extension of the hiatuses between each other
are given by the interpretation of taxonomic differences
derived from the processes of anagenesis, extinction and
migration (Montalvo et al., 2012; Tomassini et al., 2013b).
This idea was somehow implicit when the non-contempo-
raneity of some “Huayquerian” assemblages was proposed
(e.g., Verzi et al., 2008; Deschamps et al., 2013).
Taking a look at the time represented in the studied lo-
calities according to the mammal record (see Fig. 2), it is
evident that the interval between the Montehermosan and
Bonaerian (Chapadmalalan, Marplatan and Ensenadan, or
following our scheme, the Late Pliocene–Early Pleistocene)
is not represented in the area or has not been found yet.
During this interval, even the sedimentological record is
poor, because this area would have been affected by ero-
sion processes and no deposition (Quattrocchio et al., 2008).
Certainly the regional geological model proposed to explain
the geographical distribution and antiquity of the faunal
associations will help in elucidating this issue.
The Bonaerian is represented at Bajo San José. The
deposits of the San José Sequence in this locality were
accumulated by a braided river (Borromei, 1990). The age of
the locality was inferred through the record of Ctenomys
kraglievichi. This large and peculiar octodontid rodent was
also found in Pleistocene localities of the Atlantic coast
(Necochea, northern Mar del Plata, and also Uruguay; Verzi
et al., 2004a). No absolute dating is known so far for the
levels bearing Ctenomys kraglievichi, but biochronological
and paleomagnetic data suggest a relative dating of this
unit. Among the first ones, the association with Tolypeutes
sp. nov. and Hippidion principale, together with Megatherium
americanum, Glyptodon clavipes and Panochthus tubercula-
tus, whose biochrons encompass the Bonaerian–Lujanian.
Regarding paleomagnetic data, Ctenomys kraglievichi is
recorded at least 2.2 m above the Bruhnes-Matuyama
magnetostratigraphic boundary in northern Mar del Plata,
which suggests a younger age than 0.78 Ma.
With respect to the paleoclimatic inferences, C. kraglievichi
is associated in Bajo San José and the other localities, with
other caviomorph rodents that represent an immigration
event triggered by an important warm climatic pulse (Vuce-
tich et al., 1997; Vucetich and Verzi, 2002). The finding of the
specimens of Necochea was quite significant. This rodent
appears in a single sequence with other micromammal re-
mains. The extinction of the taxa found in older levels is
accompanied by the sudden appearance of C. kraglievichi
associated with the single record of a post-Pliocene eu-
mysopine echimyid rodent at this latitude, and the single
dasyproctid recorded in the Pleistocene of Argentina. Both
species and C. kraglievichi are clearly Brazilian immigrants
to the southern-southeastern Buenos Aires Province. In
Bajo San José, C. kraglievichi is associated with sigmodon-
tine rodents (e.g., Lundomys; Pardiñas and Deschamps, 1996)
and a tayassuine also suggesting a strong warm pulse.
This warm pulse is in agreement with the relative high sea
level proposed for the deposition of the San José Sequence
through the analysis of sequence stratigraphy (Zavala
and Quattrocchio, 2001). The climatic change identified in
the C. kraglievichi Zone may correspond to the warm pulse
at 0.4 Ma of the MIS 11 (see discussion in Verzi et al.,
2004a).
Mammal remains from the Late Pleistocene in the area
are scarce, but suggest that it was a mostly arid period.
After the influence of immigrant mammals entering through
the Panamá corridor from Central and North America in the
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set of events known as GABI (Great American Biotic Inter-
change), the composition of the mammal assemblages was
already established. The major changes observed since the
extinction of the megafauna are mostly due to responses to
climatic-environmental change. The reaction is more evi-
dent in those populations that inhabit the extremes of the
geographical distribution of the species (Millien et al., 2006,
and literature therein). Precisely, the southwest of the
Buenos Aires Province is an ecotonal area between the
Guayano-Brasileña and Andino-Patagónica Subregions
(sensu Ringuelet, 1961), where the extremes of the geo-
graphical distribution of the species from both subregions
are in close interaction.
This interval is recorded in Puesto La Florida, Chacra La
Blanqueada, García del Río, Balneario Saldungaray, and
Playa del Barco. The deposits are similar to those found in
the banks of rivers and creeks of the east of the Buenos
Aires Province (the Pampa Ondulada and Interserrana)
with Lujanian deposits. They correspond mainly to channel
deposits of plains rivers with differences related to the
proximity of the ranges.
Holocene deposits are recorded in the same localities,
overlying the Late Pleistocene levels. They are also similar
to those of the Pampa Ondulada and Interserrana where the
Platan was recognized. Most of the remains were found in
the upper levels of the middle section of the Agua Blanca
Sequence. In this sector of the profile, a conspicuous lami-
nation is observed. The best represented locality of this in-
terval is Chacra Santo Domingo, where a Brazilian and/or
aquatic vertebrate fauna (fish, anurans, Anas platalea, Den-
drocygna, Holochilus brasiliensis and Cavia aperea) agree
with the hydrophytic communities found in pollen analyses.
The southern expansion of Brazilian fauna coexisted with
central and Patagonian elements (Chaetophractus villosus,
Zaedyus pichiy, Lama guanicoe, Reithrodon auritus, Pseudalo-
pex gymnocercus, among others) suggesting the ameliora-
tion of previous arid and semiarid conditions. As well, water
bodies could have locally modified the arid conditions favoring
the ingression of the Brazilian fauna, and the presence of
endemic forms could have been favored by the influence of
the nearby ranges (Quattrocchio et al., 1988; Deschamps
and Tonni, 1992).
ACKNOWLEDGMENTS
This contribution is dedicated to Dr. Mirta E. Quattrocchio who
greatly influenced and helped in our careers. The revisions of Dr.
M.G. Vucetich and Dr. D.H. Verzi greatly improved the manuscript.
CMD thanks Mr. Heraclio Ortiz who helped enormously in fieldwork
with enthusiasm and good humor, and found many of the studied
specimens. Research was partially supported by the Agencia Na-
cional de Promoción Científica y Tecnológica (PICT 2012-1483 and
PICT 2012-2674), and Programa de Incentivos N645, UNLP, Ar-
gentina.
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Doi: 10.5710/PEAPA.16.05.2016.113
Recibido: 30 de marzo de 2016
Aceptado: 16 de mayo de 2016
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DESCHAMPS AND TOMASSINI: LATE CENOZOIC VERTEBRATES FROM SOUTHERN PAMPEAN REGION
APPENDIX 1. Systematic list. Record in the studied localities.
Taxa Localities
CS BSar CV CRS FMH LO BalS BSJ PLF CSD GdR PdB
Class Osteichthyes
Order Siluriformes
Pimelodella aff. P. laticeps Eigenmann, 1917 X
Callichthys callichtys Linné, 1758 X
Corydoras cf. C. paleatus (Jenyns, 1842) X
Siluriformes indet.X
Trichomycteridae indet.X
Order Perciformes
Percichthys sp.X
Plesiopercichthys dimartinoi Agnolin et al., 2014 X
Order Characiformes
Characidae indet.X
Class Amphibia
Order Anura
Rhinella cf. R. pisanoi Casamiquela, 1967 X
Rhinella cf.R. schneideri Werner, 1894 X
Ceratophrys ameghinorum Fernicola, 2001 X
Lepidobatrachus australis Nicoli, 2015 X
Leptodactylus sp. X
Class Reptilia
Order Chelonii
Chelonoidis australis (Moreno, 1889) X
Hydromedusa tectifera (Cope, 1869) X
Order Squamata
Tupinambis sp.X
Callopistes bicuspidatus Chani, 1976 X
Colubridae indet.X
aff. Bothrops Wagler, 1824 X
Boa sp.X
Class Aves
Order Anseriformes
Anas platalea Vieillot, 1816 X X
Anas sp.X
Chloephaga sp. 1 X
Chloephaga sp. 2 X
Dendrocygna sp. X
Dendrocygninae indet.X
Anatidae indet.X
Order Tinamiformes

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Taxa Localities
CS BSar CV CRS FMH LO BalS BSJ PLF CSD GdR PdB
Nothura parvula Tambussi, 1989 X
Nothura darwini Gray, 1840 X X
Eudromia cf. E. elegans Geoffroy St. Hillaire, 1832 X
Eudromia olsoni Tambussi and Tonni, 1985 X
Tinamidae indet. X
Order Rheiformes
Heterorhea dabbenei Rovereto, 1914 X
Hinasuri nehuensis Tambussi, 1995 X
Rhea americana (Linné, 1758) X
Rhea sp.X X
Order Ralliformes
Mesembriornis milneedwardsi Moreno, 1889 X
Chunga incerta Tonni, 1974 X
Order Gruiformes
Porphyrio sp. X
Order Ciconiiformes
Vultur gryphus Linné, 1758 X
Dryornis pampeanus Moreno and Mercerat, 1891 X
Order Passeriformes
Pseudoseisura-Pseudoseisuropsis X
Motacillinae indet. X
Class Mammalia
Order Didelphimorphia
Thylatheridium pascuali Reig, 1958 X
Thylamys contrerasi Mones, 1980 X
Thylamys pusillus (Desmarest, 1804) X
Thylophorops aff.T. perplana Ameghino, 1904 X
Lutreolina tracheia Rovereto, 1914 X
Lutreolina biforata Rovereto, 1914 X
Hyperdidelphys inexpectata Ameghino, 1889 X
Hyperdidelphys parvula Rovereto, 1914 X
Sparassocynus bahiai Mercerat, 1899 X
Lestodelphys halli (Thomas, 1921) X
Lestodelphys sp.X
Order Sparassodonta
Notocynus hermosicus Mercerat, 1891 X
Achlysictis lelongi Ameghino, 1891 X
Borhyaenidium sp.X
Order Polydolopimorphia
Argyrolagus palmeri Ameghino, 1904 X
Microtragulus argentinus Ameghino, 1904 X

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Taxa Localities
CS BSar CV CRS FMH LO BalS BSJ PLF CSD GdR PdB
Order Cingulata
Euphractini sp. “a” nov. Scillato-Yané, 1982 X
Holozaedyus laevisculptus Rovereto, 1914 X
Zaedyus pichiy (Desmarest, 1804) X X X
Chaetophractus villosus (Desmarest, 1804) X X X X
Tolypeutes matacus (Desmarest, 1804)
Tolypeutes sp. nov. (Scillato Yané in Deschamps, 2005) X
Macrochorobates chapalmalensis Scillato-Yané 1980 X
Macrochorobates sp. X
Chorobates villosissimus (Rovereto, 1914) X X X
Chorobates rescens (Ameghino, 1887) X
Chorobates sp. X
Macroeuphractus retusus Ameghino, 1887 X
Macroeuphractus cf. M. morenoi (Lydekker, 1894) X
Propraopus sp. X
Eutatus seguini Gervais, 1867 X X
“Eutatus” praepampaeus Ameghino, 1904 X
Doellotatus inornatus (Rovereto, 1914) X X
Doellotatus cf. D. praecursor (Rovereto, 1914) X
Doellotatus chapadmalensis Bordas, 1933 X
Ringueletia simpsoni (Bordas, 1933) X
Chasicotatus cf. C. peiranoi Esteban and Nasif, 1996 X
Plaina cf. P. intermedia (Ameghino, 1888) X
Pampatherium sp.X
Eosclerocalyptus lineatus Ameghino, 1888 X
Sclerocalyptus ornatus (Owen, 1845) X
Neosclerocalyptus sp. X
Berthawyleria sp. X
Aspidocalyptus sp. X
Trachycalyptus sp. nov. Scillato-Yané et al., 1995 X
Panochthus tuberculatus (Owen, 1839) X
Panochthus sp.X
Doedicurus sp. X
Doedicurus clavicaudatus (Owen, 1847) X
Glyptodon clavipes Owen, 1839 X X
Glyptodon reticulatus Owen, 1845 X
Nopachtus cabrerai Zamorano et al., 2011 X
Plohophorus figuratus Ameghino, 1887 X
Plohophorus cuneiformis Ameghino, 1904 X X
Plohophoroides sp.X
cf. Hoplophorus X

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Taxa Localities
CS BSar CV CRS FMH LO BalS BSJ PLF CSD GdR PdB
Phlyctaenopyga trouessarti (Moreno, 1888) X
Eleutherocercus antiquus (Ameghino, 1887) X
Palaeodaedicurus antiquus Ameghino, 1889 X
Order Tardigrada
Proscelidodon patrius Ameghino, 1889 X
Scelidotherium leptocephalum Owen, 1839 X X X
Scelidotheriumcf. S. tarijenseGervais and Ameghino, 1880 X
Glossotherium sp. X X X
Lestodon armatus Gervais, 1855 X X
Lestodon sp.X
Megatherium americanum Cuvier, 1796 X X
Myrmecophaga caroloameghinoi Kraglievich, 1934 X
Order Rodentia
Phtoramyscf. P. hidalguense Pascual, Pisano and Ortega, 1965 X X
Phtoramys homogenidens Ameghino, 1887 X
aff.Neophanomys biplicatus Rovereto, 1914 X
Neophanomys sp.X
Pithanotomys columnaris Ameghino, 1887 X
Pithanotomys macer Ameghino, 1888 X
Pseudoplataeomys formosus Kraglievich, 1934 X
Eucelophorus cabrerai Kraglievich, 1927 X
Xenodontomys ellipticus Kraglievich, 1927 X X X
Actenomys priscus (Owen, 1840) X X
Eumysops laeviplicatus Ameghino, 1888 X
Eumysops formosus Ameghino, 1906 X
Ctenomys talarum Thomas, 1898 X X X
Ctenomys sp.X
Ctenomys kraglievichi (Rusconi, 1930) X
Myocastor columnaris Rusconi, 1929 X
Paramyocastor diligens (Ameghino, 1888) X
Lagostomus incisus (Ameghino, 1888) X
Lagostomus sp.X X X X X
Lagostomus maximus (Desmarest, 1817)
Palaeocavia sp.X X X
Neocavia depressidens Parodi and Kraglievich, 1948 X
Neocavia sp.X
Dolicavia sp. X
Galea sp. X
Microcavia sp. X X
Cavia aperea Erxleben, 1777 X X X
Orthomyctera sp. X X X

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Taxa Localities
CS BSar CV CRS FMH LO BalS BSJ PLF CSD GdR PdB
Prodolichotis sp.X
Caviodon australis (Ameghino, 1888) X
Cardiomys sp.X
Phugatherium cataclisticum Ameghino, 1889 X
Neochoerus cf.N. tarijensis (Ameghino, 1902) X X
Telicomys giganteus Ameghino, 1904 X
Phyllotini gen. et sp. nov. Bond et al., 1998 X
Necromys bonapartei (Reig, 1978) X
Auliscomys formosus Reig, 1978 X
Reithrodon auritus (Fischer, 1814) X X X
Lundomys sp. X
Holochilus brasiliensis (Desmarest, 1819) X
Akodon azarae (Fischer, 1829) X
Akodon iniscatus Thomas, 1919 X
Oxymycterus sp.X
Calomys laucha (Fischer, 1814) - C. musculinus (Thomas, 1913) X
Phyllotis sp. X
Order Lagomorpha
Lepus europaeus Linné, 1758 X
Order Notoungulata
Paedotherium bonaerense Ameghino, 1887 X X X
Paedotherium typicum Ameghino, 1887 X
Paedotherium cf. P. minor Cabrera, 1937 X X
Paedotherium sp. X
Tremacyllus impressus Ameghino, 1888 X X
Tremacyllus cf. T. impressus X
Hemihegetotherium sp.
Pseudotypotherium sp.X X
Toxodon chapalmalensis Ameghino, 1908 X
Toxodon platensis Owen, 1837 X X
Alitoxodon vetustum Rovereto, 1914 X
Trigodon gaudryi Ameghino, 1882 X
Trigodon minor Rovereto, 1914 X
Xotodon prominens Ameghino, 1889 X
Xotodon ambrosetti Rovereto, 1914 X
Xotodon sp.X
Order Litopterna
Eoauchenia primitiva Ameghino, 1887 X
Epitherium laternarium Ameghino, 1888 X X
Diplasiotherium robustum Rovereto, 1914 X
Promacrauchenia antiqua Ameghino, 1889 X

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Taxa Localities
CS BSar CV CRS FMH LO BalS BSJ PLF CSD GdR PdB
Promacrauchenia kraglievichi Parodi, 1931 X
Promacrauchenia sp.X
Macraucheniopsis ensenadensis (Ameghino, 1888) X
Macrauchenia patachonica Owen, 1838 X X
Order Proboscidea
Notiomastodon platensis (Ameghino, 1888) X
Gomphotheriidae indet. X
Order Artiodactyla
Tayassuinae indet. X
Lama sp.X
Lama guanicoe (Müller, 1776) X X X
Ozotoceros bezoarticus (Linné, 1758) X X
Morenelaphus bonaerense Carette, 1922 X
Ovis aries Linné, 1758 X X
Bos taurus Linné, 1758 X X
Order Perissodactyla
Equus (Amerhippus) neogaeus Lund, 1840 X X
Hippidion principale (Lund, 1846) X
Hippidion sp.X
Order Carnivora
Parahyaenodon argentinus Ameghino, 1904 X
Tetraprothomo argentinus Ameghino, 1908 X
Cyonasua clausa Ameghino, 1904 X
Smilodon populator Lund, 1842 X
Pseudalopex sp.X
Pseudalopex gymnocercus (Fischer, 1814) X
cf. Herpailurus X
BalS, Balneario Saldungaray; BSar, Barrancas de Sarmiento; BSJ, Bajo San José; CSD, Chacra Santo Domingo; CRS, Cantera Relleno Sanitario;
CS, Cantera Seminario; CV, Cantera Vialidad; FMH, Farola Monte Hermoso; GDR, García del Río; LO, Las Oscuras; PdB, Playa del Barco; PLF,
Puesto La Florida.