ArticlePDF Available

The Tinguiririca Fauna of Chile and the early stages of "modernization" of South American mammal faunas

Authors:

Figures

Content may be subject to copyright.
1 Submitted on September 14, 2006. Accepted on February 19, 2008.
2 Case Western Reserve University, Department of Anatomy. Cleveland, OH 44106, USA. E-mail: dcroft@case.edu.
3 American Museum of Natural History, Division of Paleontology. New York, NY 10024, USA. E-mail: jflynn@amnh.org.
4 University of California, Department of Earth Science. Santa Barbara, CA 93106, USA. E-mail: wyss@geol.ucsb.edu.
Arquivos do Museu Nacional, Rio de Janeiro, v.66, n.1, p.191-211, jan./mar.2008
ISSN 0365-4508
THE TINGUIRIRICA FAUNA OF CHILE AND THE EARLY STAGES
OF “MODERNIZATION” OF SOUTH AMERICAN MAMMAL FAUNAS1
(With 7 figures)
DARIN A. CROFT2
JOHN J. FLYNN 3
ANDRÉ R. WYSS4
ABSTRACT: The evolution of South American Cenozoic mammal communities is generally seen as
encompassing three distinct “faunal strata”. The recently formalized Tinguirirican South American Land
Mammal “Age” (SALMA) represents the earliest interval within Simpson’s second faunal stratum and presents
an exceptional opportunity to investigate a remarkable period of faunal “modernization” in South America.
Of the 25 species currently recognized from the Tinguiririca Fauna, 17 are notoungulates, illustrating the
group’s diversity and abundance during this interval. Two-thirds of notoungulate species are hypsodont, in
marked contrast with earlier faunas, indicating the nearly simultaneous convergent appearance of this
feature in several notoungulate clades. The most diverse and abundant notoungulates at Tinguiririca are
archaeohyracids (six species, the highest diversity for any locality known to date), notohippids (four species),
and interatheriids (two species). Large, brachydont notoungulates are scarce. In addition to the fauna from
the type locality in central Chile, several Patagonian faunas of Tinguirirican age provide important
complementary taxonomic and biogeographic data. Hegetotheriids are absent from the Tinguiririca Fauna
but are reported from Tinguirirican faunules in Patagonia. Trachytheriine mesotheriids are uncommon during
the Tinguirirican; they have previously been reported only from Rocas Bayas in Rio Negro, though a recently
prepared Chilean specimen indicates presence of the group just north of Tinguiririca during this SALMA.
Faunal hypsodonty, cenograms, and rainfall estimates have previously been used to suggest that the
Tinguiririca Fauna is the earliest open-habitat community in South America. This conclusion is corroborated
herein through an ecological diversity analysis (EDA) that consolidates browsers and grazers into a single
dietary category, to counter potential errors in hypsodonty-based dietary interpretations of extinct taxa. The
statistically significant results of a multivariate discriminant model based on this EDA confirm the resemblance
of the Tinguiririca Fauna to modern open habitat communities, further supporting the presence of open
habitats in high latitude South America by earliest Oligocene time, despite the apparent lack of a substantial
regional climatic shift across the Eocene-Oligocene Transition in Argentine Patagonia.
Key words: South American Land Mammal “Age”. Notoungulate. Ecological diversity analysis. Tinguiririca
Fauna. Chile.
RESUMO: A Fauna de Tinguiririca do Chile e os primeiros estágios de “modernização” das faunas de mamíferos
sul-americanos.
A evolução das comunidades de mamíferos cenozóicos sul-americanos é geralmente vista como abrangendo
três “estratos faunísticos” distintos. A recentemente formalizada “Idade” Tinguiririquense de Mamíferos
Terrestres Sul-americanos representa o intervalo mais antigo do segundo estrato faunístico de Simpson e
fornece uma oportunidade excepcional para se investigar um período notável de “modernização” faunística
na América do Sul. Das 25 espécies atualmente reconhecidas para a Fauna de Tinguiririca, 17 são de
notoungulados, ilustrando a diversidade e a abundância do grupo durante este intervalo. Dois terços das
espécies de notoungulados são hipsodontes, em contraste marcante com as faunas mais antigas, indicando
um surgimento convergente quase simultâneo desta característica em vários clados de notoungulados. Os
mais diversos e abundantes notoungulados em Tinguiririca são os representantes de Archaeohyracidae (seis
espécies, a mais alta diversidade para qualquer localidade conhecida), de Notohippidae (quatro espécies), e
de Interatheriidae (duas espécies). Notoungulados de grande porte braquiodontes são raros. Além da fauna
da localidade tipo no centro Chile, várias faunas da Patagônia, de idade Tinguiririquense, fornecem importantes
dados taxonômicos e biogeográficos complementares. Os representantes de Hegetotheriidae estão ausentes
192 D.A.CROFT, J.J.FLYNN & A.R.WYSS
Arq. Mus. Nac., Rio de Janeiro, v.66, n.1, p.191-211, jan./mar.2008
da Fauna de Tinguiririca, mas são reportados para a fáunula Tinguiririquense na Patagônia. Os
Trachytheriinae, representantes dos Mesotheriidae, não são comuns no Tinguiririquense; eles foram
previamente registrados apenas para Rocas Bayas em Rio Negro, embora um espécime recentemente preparado
indique a presença do grupo apenas ao norte de Tinguiririca durante a “Idade” de Mamíferos Terrestres Sul-
americanos. A hipsodontia faunística, os cenogramas e as chuvas estimadas foram previamente utilizados
para sugerir que a Fauna de Tinguiririca é a mais antiga comunidade de habitat aberto na América do Sul.
Esta conclusão é aqui corroborada através de uma análise de diversidade ecológica (ADE), que consolida
pastadores e ramoneadores em uma única categoria de dieta alimentar, indo contra erros potenciais de
interpretação de uma dieta com base na hipsodontia de táxons extintos. Os resultados estatisticamente
significantes de um modelo discriminante multivariado nesta ADE confirmam a semelhança da Fauna de
Tinguiririca com as comunidades de habitat aberto, suportando, além disso, a existência de habitats abertos
em altas latitudes na América do Sul durante o início do Oligoceno, apesar da aparente ausência de mudanças
climáticas regionais substanciais durante a transição Eoceno-Oligoceno na Patagônia Argentina.
Palavras-chave: “Idade” Mamíferos Terrestres Sul-americanos. Notoungulados. Análise de diversidade
ecológica. Fauna de Tinguiririca. Chile.
INTRODUCTION
The evolution of South American Cenozoic mammal
communities is generally described as a succession
of three “faunal strata” (SIMPSON, 1980; FLYNN & WYSS,
1998; Fig.1). The oldest of these – spanning roughly
the Paleocene-Eocene –, consists of communities
dominated by the continent’s “original inhabitants”
(e.g., endemic ungulates, marsupials, xenarthrans)
(MARSHALL & MUIZON, 1988). The second stratum is
marked by the arrival of rodents (WYSS et al., 1993)
and primates (HOFFSTETTER, 1969) and the
appearance of notable morphological advances
within many of the original endemic clades. The
final stratum is marked by extensive late Cenozoic
interchange with North America and the extinction
of many of the last remaining endemic clades (WEBB,
1976; MARSHALL et al., 1982). The recently formalized
Tinguirirican South American Land Mammal “Age”
(SALMA) represents the earliest interval within
Simpson’s second faunal stratum (WYSS et al., 1994;
FLYNN et al., 2003). As such, the Tinguiririca Fauna
of central Chile (the best-sampled and most diverse
fauna of Tinguirirican age) presents an exceptional
opportunity to investigate the transition from
Stratum 1 to 2, a remarkable period of faunal
“modernization” in South America (PASCUAL et al.,
1985; FLYNN & WYSS, 1998; FLYNN et al., 2007).
In addition to the fauna from the type locality in
central Chile, a handful of Tinguirirican SALMA
faunas occur in Patagonia (see FLYNN et al., 2003);
although most of these faunas remain poorly
sampled, they provide important, complementary
taxonomic and biogeographic data. One of these,
Cañadón Blanco in Chubut, Argentina, discovered
by Santiago Roth (ROTH, 1901, 1903), was long
mistakenly considered a temporally mixed fauna
(e.g., SIMPSON, 1967). In light of our findings in Chile,
most of the fossils from Cañadón Blanco are now
seen as pertaining to the Tinguirirican (WYSS et al.,
1994; FLYNN et al., 2003), but the locality has yet to
be relocated. Ameghino (AMEGHINO, 1901, 1902a)
designated a faunally distinctive interval at the
Gran Barranca south of Lago Colhué Huapí in
Chubut as the “Astraponotéen plus supérieure”
(APS) level; he later subsumed the APS within the
Mustersan SALMA, but this post-Mustersan/pre-
Deseadan faunal interval is now recognized as
pertaining to the Tinguirirican as well (WYSS et al.,
1994; BOND et al., 1996; FLYNN et al., 2003; see
also KAY et al., 1999; CARLINI et al., 2005). Other
smaller Argentine faunules of Tinguirirican age
include Rocas Bayas in Río Negro province and a
variety of others in Chubut (e.g., Laguna La
Bombilla, Lomas Blancas/La Curandera, Campo
de Velázquez/Paso de Indios, and Laguna Seca)
(BOND et al., 1997; HITZ et al., 2000; FLYNN et al.,
2003). The new Chilean locality of Cachapoal may
also be of Tinguirirican age (FLYNN & WYSS, 2004;
HITZ et al., 2006) as might other recently discovered
central Chilean localities yielding characteristic
Tinguirirican taxa (e.g., various archaeohyracid
and interatheriid species).
The purpose of the present brief report is twofold: to
provide an overview of Tinguirirican ungulates in a
biogeographic context and to apply a new
ecomorphological method of paleohabitat
reconstruction to the Tinguiririca Fauna. We
recognize that the names Notohippidae,
Notopithecinae, Trachytheriinae, Archaeohyracidae,
and Hegetotheriinae likely refer to paraphyletic
groups, but we continue to use them in their
traditional sense until phylogenetically based names
of the relevant clades are formally defined.
FAUNA OF CHILE AND THE EARLY STAGES OF “MODERNIZATION” OF SOUTH AMERICA MAMMAL FAUNAS 193
Arq. Mus. Nac., Rio de Janeiro, v.66, n.1, p.191-211, jan./mar.2008
RESULTS AND DISCUSSION
UNGULATE DIVERSITY AND BIOGEOGRAPHY
Ungulates are the most conspicuous component
of the Tinguiririca Fauna, accounting for more than
two-thirds of alpha diversity (Tab.1). Nearly all of
these are notoungulates (Fig.2), a group whose
diversity peaked in the Oligocene (CIFELLI, 1985b;
MARSHALL & CIFELLI, 1989; CROFT, 1999). Many of
these ungulates are present in other Tinguirirican
faunas and are important biochronologically,
permitting the recognition of Tinguirirican faunas
in other parts of the continent (HITZ et al., 2000,
2006; CROFT et al., 2003a; REGUERO et al., 2003a).
The following section provides an overview of the
major groups of Tinguirirican ungulates in their
biogeographic and temporal contexts. Figure 3
provides a map of the main Tinguirirican localities
and other localities discussed in the text. Recent
studies suggest that the peculiar “Divisadero Largo
Fauna” of west-central Argentina – generally
considered to be late Eocene (BOND, 1991; FLYNN &
SWISHER, 1995; FLYNN et al., 2003) – is a mixed fauna
including both ?early-middle Eocene specimens (from
the Divisadero Largo Formation) and ?early Miocene
specimens (from the overlying Mariño Formation)
(CERDEÑO et al., 2005; LÓPEZ & MANASSERO, 2006). We
therefore follow these authors in rejecting the
“Divisaderan” SALMA, and below we treat specimens
from this locality as either Eocene or Miocene in age.
NOTOSTYLOPIDAE
A single specimen from the type locality of the
Tinguiririca Fauna marks the last appearance of
the Notostylopidae (WYSS et al., 1994; FLYNN et al.,
2003) but additional unprepared notostylopid
specimens may be present in the Chilean
collections. The Tinguiririca notostylopid most
closely resembles Otronia muehlbergi from the
Mustersan of Chubut (SIMPSON, 1967) and
Boreastylops lumbrerensis from the Casamayoran
of Salta Province (VUCETICH, 1980), but likely
represents a new species (WYSS et al., 1994).
Notostylopids are first recorded from the
Itaboraian and Riochican of Chubut (BOND,
1986). They are abundant and characteristic
components of Patagonian Casamayoran faunas
(SIMPSON, 1948, 1984; BOND, 1986) and are
present in both subdivisions of that SALMA,
the Vacan and Barrancan (CIFELLI, 1985a).
Fig.1- “Three stratum” model of mammalian faunal
succession in South America highlighting major events in
ungulate evolution. The three strata are calibrated to the
timescale on the left, but the events listed for each stratum
are not. FA and LA represent First Appearance and Last
Appearance, respectively. The SALMA sequence is based
primarily on FLYNN & SWISHER (1995) and FLYNN et al. (2003);
the four youngest SALMAs have been consolidated to
increase legibility.
194 D.A.CROFT, J.J.FLYNN & A.R.WYSS
Arq. Mus. Nac., Rio de Janeiro, v.66, n.1, p.191-211, jan./mar.2008
Notostylops itself is especially well-represented in
Casamayoran assemblages (e.g., SIMPSON, 1932a,
1948; RIGGS & PATTERSON, 1935), forming the basis
for Ameghino’s original designation for these
faunas, the “Notostylops beds” (SIMPSON, 1984).
Otronia is the only described Mustersan
notostylopid (SIMPSON, 1948; BOND, 1986), although
LÓPEZ (1997) has noted a new notostylopid species
from Antofagasta de la Sierra, an Eocene fauna of
uncertain SALMA assignation.
The Tapado Fauna documents the presence of
notostylopids in central Chile during the late Eocene,
probably during the Casamayoran (WYSS et al., 1996;
FLYNN et al., 2005a). Notostylopids have not been
recorded from the Divisadero Largo Fauna of Mendoza
province (SIMPSON et al., 1962). This absence is likely
an artifact of sampling given that notostylopids were
present throughout Patagonia, northwest Argentina,
and central Chile during this interval.
INTERATHERIIDAE
The Tinguirirican is unique among SALMAs in
documenting the co-occurrence of both traditional
subfamilies of interatheriids: low-crowned
notopithecines and higher crowned interatheriines
(WYSS et al., 1994; HITZ et al., 2000, 2006; FLYNN et
al., 2003). In this regard, the interatheriids mimic
the Tinguirirican SALMA as a whole, in that various
“archaic” taxa co-occur with members of clades
marked by more derived morphologies (WYSS et al.,
1993, 1994; FLYNN et al., 2003).
TABLE 1. Tinguiririca faunal list and corresponding ecomorphological variables for each taxon.
Dietary abbreviations: FR, frugivore; FO, folivore; I, insectivore; O, omnivore. Locomotor abbreviations: A, arboreal;
T, terrestrial. Body mass categories: I, 1-200 g; II, 201-400 g; III, 401-800 g; IV, 801-1600 g; V, 1.6-3.2 kg; VI, 3.2-
6.4 kg; VII, 6.4-12.8 kg; VIII, 12.8-25.6 kg; IX, 25.6-51.2 kg; X, 51.2-102.4 kg; XI, 102.4-204.8 kg; XII, 204.8+ kg.
TAXON ORDER FAMILY DIET LOCOMOTION MASS
Klohnia charrieri Marsupialia Groeberiidae FR A I
Polydolops abanicoi Marsupialia Polydolopidae FR A IV
Pascualdelphys fierroensis Marsupialia (Didelphimorphia) I A I
gen. et sp. indet. Xenarthra Dasypodidae O T V
Pseudoglyptodon chilensis Xenarthra Phyllophaga (i.s.) FO T VI
Indaleciinae gen. et sp. nov. Incertae sedis incer tae sedis FO T III
gen. et sp. nov. Rodentia ?Dasyproctidae FR T IV
?Prolagostomus sp. Rodentia Chinchillidae FO T III
gen. et sp. nov. Notoungulata Notostylopidae FO T VI
Notopithecinae gen. et sp. nov. Notoungulata Interatheriidae FO T I
Santiagorothia chiliensis Notoungulata Interatheriidae FO T IV
Archaeotypotherium tinguiriricaense Notoungulata Archaeohyracidae FO T V
Archaeotypotherium pattersoni Notoungulata Archaeohyracidae FO T VI
Protarchaeoh yrax gr acilis Notoungulata Archaeohyracidae FO T IV
Protarchaeohyrax intermedium Notoungulata Archaeohyracidae FO T II
Pseudhyrax strangulatus Notoungulata Archaeohyracidae FO T V
Pseudhyrax eutrachytheroides Notoungulata Archaeohyracidae FO T V
cf. Rhyphodon sp. Notoungulata Isotemnidae FO T XI
Trigonolophodon cf. elegans Notoungulata Homalodotheriidae FO T IX
Periphragnis sp. Notoungulata Homalodotheriidae FO T IX
Eomorphippus sp. nov. Notoungulata Notohippidae FO T VIII
“Eomorphippus” cf. pascuali Notoungulata Notohippidae FO T VII
gen. et sp. nov. A (large) Notoungulata Notohippidae FO T VIII
gen. et sp. nov. B (small) Notoungulata Notohippidae FO T VI
incertae sedis Notoungulata Leontiniidae FO T X
FAUNA OF CHILE AND THE EARLY STAGES OF “MODERNIZATION” OF SOUTH AMERICA MAMMAL FAUNAS 195
Arq. Mus. Nac., Rio de Janeiro, v.66, n.1, p.191-211, jan./mar.2008
The Tinguiririca Fauna itself includes two
interatheriids: Santiagorothia (a basal interatheriine;
Fig.2D) and a new species of basal interatheriid (HITZ
et al., 2000, 2006; FLYNN et al., 2003). Besides in the
Tinguiririca Valley, Santiagorothia occurs at virtually
every Tinguirirican locality in Patagonia with the
exception of Cañadón Blanco (HITZ et al., 2000),
whereas the new basal interatheriid appears to be
endemic to central Chile (HITZ et al., 2006). The
interatheriine Eopachyrucos occurs in the
Tinguirirican APS level of Gran Barranca, Cañadón
Blanco, and Rocas Bayas; the interatheriine
Proargyrohyrax has been reported from the Gran
Barranca (LÓPEZ et al., 2005) and Lomas Blancas (HITZ
et al., 2000). Outside of Chile, basal interatheriids of
Tinguirirican age have only been reported from the
Gran Barranca (e.g., La Cancha; LÓPEZ et al., 2005).
Interestingly, a basal interatheriid distinct from that
Fig.2- Representative notoungulate specimens from the Tinguiririca Fauna of central Chile. A, SGO PV 2923, holotype
palate of Archaeotypotherium tinguiriricaense, occlusal view (cast); B, SGO PV 2998, palate referred to Protarchaeohyrax
intermedium, occlusal view (cast); C, SGO PV 3046, skull of Eomorphippus sp. nov.; D, SGO PV 2914, holotype skull and
mandibles of Santiagorothia chiliensis (left lateral view, reversed); E, SGO PV 2900, skull referred to Archaeotypotherium
tinguiriricaense, right lateral view. Scale bar = 1cm.
196 D.A.CROFT, J.J.FLYNN & A.R.WYSS
Arq. Mus. Nac., Rio de Janeiro, v.66, n.1, p.191-211, jan./mar.2008
of the Tinguiririca Fauna occurs at the more recently
discovered locality of Cachapoal (HITZ et al., 2006); at
least one currently unidentified species of
interatheriine is also present in that fauna.
The only interatheriids present prior to the
Tinguirirican are basal members of the clade (i.e.,
notopithecines or non-interatheriines), the earliest
occurrence of which is in the Riochican of Patagonia
(SIMPSON, 1935b, 1967; BOND, 1986). Notopithecus and
similar forms are abundant and characteristic of
Casamayoran faunas (SIMPSON, 1967), although they
are apparently restricted to the Barrancan (younger)
subdivision in Patagonia (CIFELLI, 1985a).
Guilielmoscottia occurs in the Mustersan of Patagonia
(SIMPSON, 1967; MARSHALL et al., 1983), and may also
occur in the Tinguirirican (LÓPEZ et al., 2005). A
diminutive basal interatheriid, Punapithecus, has
been described from the indeterminate Eocene fauna
of Antofagasta de la Sierra (LÓPEZ & BOND, 1995;
LÓPEZ, 1997). Two other small basal interatheriids
are now known from Eocene deposits in Chile, a
new diminutive taxon from the Tapado Fauna and
Antepithecus from the Azufre Fauna (HITZ et al.,
2006). As is the case for notostylopids, interatheriids
are absent from Divisadero Largo, probably due to
small sample sizes.
Fig.3- Map of primary localities discussed in the text; localities with Tinguirirican-aged intervals are designated by a star.
FAUNA OF CHILE AND THE EARLY STAGES OF “MODERNIZATION” OF SOUTH AMERICA MAMMAL FAUNAS 197
Arq. Mus. Nac., Rio de Janeiro, v.66, n.1, p.191-211, jan./mar.2008
SHOCKEY et al. (2004) reported a small, indeterminate
interatheriine from the Paleogene fauna of Santa
Rosa in the lowland Peruvian Amazon. That locality
has been considered late Eocene (possibly
Mustersan) in age (CAMPBELL et al., 1996, 2004;
CAMPBELL, 2004), which would make this taxon the
earliest known interatheriine. The interatheriine
and the other notoungulates from Santa Rosa are
more indicative of an Oligocene age for the fauna,
however (SHOCKEY et al., 2004), and given the general
reliability of notoungulates for biochronologic
correlation, this age assignment seems more likely.
Regardless, Santa Rosa is the northernmost record
of interatheriids in South America prior to the
middle Miocene.
MESOTHERIIDAE
Mesotheriids are rare in Tinguirirican faunas; no
specimens have been collected from the type locality
in Chile, nor have any been reported from the APS
level at Gran Barranca or Cañadón Blanco (FLYNN et
al., 2003). A trachytheriine specimen from Rocas
Bayas in Río Negro, Argentina does record the
presence of the clade in western Argentina during
this interval, however (BOND et al., 1997). Additionally,
we have identified a trachytheriine upper molar from
the Cachapoal Fauna of central Chile. Cachapoal may
correlate with or predate a level preliminarily dated
at 29.3 ± 0.1 Ma (i.e., early Deseadan SALMA or older)
and thus may be of Tinguirirican age (FLYNN & WYSS,
2004). This chronological assessment is supported
by the occurrence of Protarchaeohyrax and
Archaeotypotherium at Cachapoal, both typical
Tinguirirican archaeohyracids (CROFT et al., 2003a;
FLYNN et al., 2003; REGUERO et al., 2003a; see also
below). A relatively large mesotheriid (?trachytheriine)
mandible from a third central Chilean fauna of
potential Tinguirirican age further documents the
presence of mesotheriids in central Chile at this time.
The clade has long been reported from Divisadero
Largo of Mendoza, Argentina (SIMPSON & MINOPRIO,
1949) and this was thought to be the oldest
occurrence of mesotheriids (REGUERO & CASTRO, 2004).
It appears these specimens more likely derive from
the overlying Mariño Formation, however, and are
therefore Miocene in age (CERDEÑO et al., 2005).
Mesotheriids apparently increased in abundance
after the Tinguirirican; Trachytherus is a
characteristic component of Deseadan faunas and
is arguably the best known late Oligocene typothere
(MARSHALL et al., 1986; REGUERO & ESCRIBANO, 1996).
Specimens of Trachytherus (or closely related forms)
have been collected from Deseadan faunas in
Patagonia (PATTERSON, 1934; MARSHALL et al., 1986;
REGUERO & ESCRIBANO, 1996), Bolivia (MACFADDEN et
al., 1985; SYDOW, 1988; SHOCKEY, 1997a, b; SHOCKEY
et al., 2007), Perú (SHOCKEY et al., 2006), and Uruguay
(BOND et al., 1998) – essentially from all reasonably
well-sampled Deseadan faunas. The absence of
mesotheriids in the Tremembé Formation of Brazil
(BERGQVIST & RIBEIRO, 1998; VUCETICH & RIBEIRO, 2003)
and the Paleogene Santa Rosa Fauna of lowland Perú
(CAMPBELL et al., 2004; SHOCKEY et al., 2004), if not
attributable to small sample sizes, may reflect true
absence (see below).
Until recently, mesotheriids were unknown from
the earliest Miocene Colhuehuapian SALMA
(MARSHALL et al., 1983; CROFT et al., 2003b, 2004;
FLYNN et al., 2005b; KRAMARZ et al., 2004).
Trachytheriines therefore became extinct between
the Deseadan and Colhuehuapian SALMAs, and
mesotheriines evidently originated. Based on the
geographic and temporal distributions of the
earliest diverging mesotheriines (Fig.4), it seems
that this clade differentiated in the middle latitudes
of South America (FLYNN et al., 2002; CROFT et al.,
2003b, 2004). No mesotheriids are recorded from
low latitudes (i.e., north of 10° S; see KAY et al.,
1997; LINARES, 2004), however, suggesting the
presence of a geographic or ecological barrier to
their dispersal during much of the Cenozoic.
ARCHAEOHYRACIDAE
The Tinguirirican is the “Age of Archaeohyracids”;
this assemblage – paraphyletic though it may be –
exhibited greater species richness during this
period of time than at any other point in its
relatively short history (CROFT, 1999; CROFT et al.,
2003a). Not only did it achieve its own peak
diversity during this period, archaeohyracid alpha
diversity at Tinguiririca is among the highest exhibited
by any “family-level” notoungulate group for any
SALMA. The reasons for this short-lived species
richness are unknown but may relate to the group’s
early acquisition of hypsodont cheek teeth (SIMPSON,
1967; CROFT et al., 2003a). Archaeohyracids are
quite abundant at Tinguiririca; in this regard,
Tinguiririca is more similar to Salla, Bolivia than
typical Patagonian faunas.
At least six archaeohyracids are known from
Tinguiririca, two species each of Archaeotypotherium
(Fig.2A, E), Protarchaeohyrax (Fig.2B), and
Pseudhyrax (CROFT et al., 2003a; FLYNN et al., 2003,
REGUERO et al., 2003a). Archaeotypotherium and
198 D.A.CROFT, J.J.FLYNN & A.R.WYSS
Arq. Mus. Nac., Rio de Janeiro, v.66, n.1, p.191-211, jan./mar.2008
Protarchaeohyrax are recorded from the APS level at
Gran Barranca and from Cañadón Blanco (ROTH,
1903; SIMPSON, 1967; CROFT et al., 2003a; REGUERO et
al., 2003a) and are characteristic of the Tinguirirican
SALMA (FLYNN et al., 2003). Tinguiririca is the only
Tinguirirican fauna yet known to record Pseudhyrax,
a taxon otherwise typical of the Mustersan of
Patagonia (SIMPSON, 1967).
Although SIMPSON (1967) viewed archaeohyracids
as spanning the latest Riochican through
Deseadan, he noted that their occurrence in the
Riochican is doubtful. They are first definitively
known from Casamayoran faunas, with all
currently described species from this temporal
interval being referred to Eohyrax. Of the dozen
Casamayoran localities reviewed by CIFELLI (1985a),
Eohyrax occurs only in three (Gran Barranca, Río
Chico oeste, and possibly in Cañadón Lobo),
illustrating the scarcity of archaeohyracids at that
time. Moreover, these three localities predominantly
or exclusively represent the younger of CIFELLI’s
(1985a) two subdivisions of the Casamayoran, the
Barrancan, suggesting that the oldest securely
identified archaeohyracids may be substantially
younger than once thought. The northernmost
report of Eohyrax is from the Cosquín Formation
in Córdoba, Argentina (LINARES et al., 1960).
Archaeohyracids have also been reported from
Antofagasta de la Sierra in northwest Argentina, a
locality of uncertain age that may pertain to the
Fig.4- Time-calibrated phylogeny of mesotheriids based on the analysis of CROFT et al. (2004). Solid bars represent fossil
occurrences, dashed lines represent inferred phylogenetic lineages. The four youngest SALMAs have been consolidated to
increase legibility.
FAUNA OF CHILE AND THE EARLY STAGES OF “MODERNIZATION” OF SOUTH AMERICA MAMMAL FAUNAS 199
Arq. Mus. Nac., Rio de Janeiro, v.66, n.1, p.191-211, jan./mar.2008
middle or even early Eocene (LÓPEZ,
1997; REGUERO & LÓPEZ, 1999; REGUERO
et al., in press). If this age assignment
proves correct, it could represent the
earliest occurrence of the group. A
time calibrated phylogeny of
archaeohyracids suggests that a
major diversification took place at or
just prior to the Tinguirirican,
potentially coincident with the Eocene-
Oligocene Transition (Fig.5).
Archaeohyracids are last recorded in
the Deseadan where they are
represented by species of
Archaeohyrax (a primarily Deseadan
taxon) and Protarchaeohyrax (known
also from the Tinguirirican). Only
Archaeohyrax occurs in Deseadan
faunas of Patagonia (e.g., CHAFFEE,
1952; MARSHALL et al., 1986) and only
Protarchaeohyrax occurs in the Fray
Bentos Formation of Uruguay and
northeastern Argentina (REGUERO et
al., 1995; BOND et al., 1998; REGUERO
et al., 2003b). Both taxa occur in the
Deseadan at Salla, Bolivia, but
Archaeohyrax is much more
abundant than Protarchaeohyrax there (REGUERO
& CIFELLI, 1997). Archaeohyrax has also been
reported preliminarily from the Tinguirirican Rocas
Bayas locality (BOND et al., 1997), which would be
its oldest occurrence. Archaeohyracids have not
yet been recorded from the late Oligocene
Tremembé Formation of southeastern Brazil
(BERGQVIST & RIBEIRO, 1998; VUCETICH & RIBEIRO,
2003) nor from the recently described Deseadan
Moquegua Fauna of Perú (SHOCKEY et al., 2006);
neither have they been recorded from the Santa
Rosa Fauna from the Amazonian lowlands of
eastern Perú (CAMPBELL et al., 2004; SHOCKEY et al.,
2004) nor Divisadero Largo in western Argentina
(SIMPSON et al., 1962). Given the sparse sampling
at most of these localities and the scarcity of
archaeohyracids in many faunas, these absences
likely have little biogeographic significance.
HEGETOTHERIIDAE
Hegetotheriids are absent from the Tinguiririca
Fauna and the APS level at Gran Barranca; their
only Tinguirirican occurrence is at Cañadón Blanco
(BOND, 1991; REGUERO, 1993; FLYNN et al., 2003),
although several hegetotheriids specimens are now
known from Cachapoal in central Chile, potentially
also of Tinguirirican age. A skull and mandibles of a
hegetotheriid from Divisadero Largo were previously
thought to record the earliest Hegetotheriidae (SIMPSON
& MINOPRIO, 1949; SIMPSON et al., 1962), but this
specimen likely comes from the Miocene Mariño
Formation (LÓPEZ & MANASSERO, 2006).
Two hegetotheriid sub-groups are generally
recognized (SIMPSON, 1945a; MCKENNA & BELL, 1997):
Hegetotheriinae and Pachyrukhinae. Pachyrukhinae
is universally considered monophyletic (CERDEÑO &
BOND, 1998) and the clade is certainly recognizable
as early as the Deseadan (LOOMIS, 1914; SIMPSON,
1945b; DOZO et al., 2000) and potentially as early as
the Tinguirirican (REGUERO, 1993). In contrast,
Hegetotheriinae is likely paraphyletic, though it may
include a monophyletic subset of Miocene taxa
(CIFELLI, 1993; CROFT, 2000; CROFT et al., 2004;
CROFT & ANAYA, 2006). All Paleogene non-
pachyrukhine hegetotheriids have been referred
to Prohegetotherium, a taxon that occurs at
Divisadero Largo, La Cantera, and various
Deseadan localities in Patagonia (REGUERO &
CERDEÑO, 2001, 2005; LÓPEZ et al., 2005; but see
LÓPEZ, 2002), and possibly in Oligocene faunas in
Chile (e.g., Cachapoal).
Fig.5- Time-calibrated phylogeny of archaeohyracids based on the analysis
of CROFT et al. (2003a). Solid bars represent fossil occurrences; gray bars
represent interpolated occurrences; dashed lines represent inferred
phylogenetic lineages.
200 D.A.CROFT, J.J.FLYNN & A.R.WYSS
Arq. Mus. Nac., Rio de Janeiro, v.66, n.1, p.191-211, jan./mar.2008
ISOTEMNIDAE
Large, low-crowned notoungulates are poorly
represented at Tinguiririca, where only a single
species of isotemnid, cf. Rhyphodon, has been
identified. If this tentative identification is
substantiated, it would represent a temporal and
geographic range extension for the taxon, otherwise
known only from the Mustersan of Lago Musters/
Cerro del Humo in Chubut (SIMPSON, 1967).
Anisotemnus, Periphragnis, Pleurostylodon, and
Rhyphodon are known from the Tinguirirican APS
level of Gran Barranca (FLYNN et al., 2003; LÓPEZ et
al., 2005), and an indeterminate isotemnid with
affinities to Periphragnis has been reported from
Rocas Bayas (BOND et al., 1997). Both Anisotemnus
and Pleurostylodon are known from the
Casamayoran of Patagonia, with Anisotemnus
previously restricted to the Barrancan (SIMPSON,
1967; CIFELLI, 1985a); Pleurostylodon has also
recently been identified from the ?Casamayoran
Tapado Fauna of central Chile (FLYNN et al., 2005a).
Besides various Tinguirirican localities, Periphragnis
is known only from the Mustersan of Patagonia (WYSS
et al., 1994; FLYNN et al., 2003; LÓPEZ et al., 2005).
Although isotemnids appear
to be fairly diverse during the
Tinguirirican, precise
comparisons and identifica
tions are hampered by the
relatively poor material
presently known.
The Tinguirirican isotemnids
are the youngest representatives
of the group; the oldest are
Riochican in age (SIMPSON,
1935a, 1967; MARSHALL et al.,
1983). Within this time interval,
isotemnids are recorded at
most Eocene localities from
Patagonia and as far north as
Jujuy (BOND & LÓPEZ, 1995).
HOMALODOTHERIIDAE
Homalodotheriids are relative
ly large, vaguely chalicothere-
like notoungulates that were
never very diverse or
abundant (PATTERSON &
PASCUAL, 1968; SIMPSON, 1980;
COOMBS, 1983; CIFELLI, 1985b;
CROFT, 1999). SIMPSON (1967)
did not regard Mustersan Periphragnis as a
homalodotheriid, but this may very well be the
earliest member of the group (Bond, pers. comm.).
During the Tinguirirican, Trigonolophodon is present
at Tinguiririca, Cañadón Blanco, and the APS level
at Gran Barranca (WYSS et al., 1994; FLYNN et al.,
2003). The group persisted through the late Miocene
(RINGUELET, 1957).
NOTOHIPPIDAE
The phylogenetic relationships among notohippids
are only beginning to be resolved (SHOCKEY, 1997a,
b), but the group’s name (as traditionally
conceived) almost certainly does not refer to a
monophyletic entity. CIFELLI (1993) found support for
a monophyletic subgroup of Deseadan and later
notohippids, but his analysis positioned
Eomorphippus as the outgroup to a clade formed by
these later notohippids plus toxodontids. In contrast,
SHOCKEY (1997a, b) found no such support for a
monophyletic subclade, and in fact obtained very little
resolution among notohippids; most notohippids were
part of a six-way polytomy that included a clade
formed by Pascualihippus plus toxodontids (Fig.6).
Fig.6- Notohippid relationships based on the analyses of SHOCKEY (1997a, b). The
following named nodes are indicated: 1, Notohippidae sensu BOND & LÓPEZ (1993); 2,
Leontiniidae; 3, Notohippidae sensu SIMPSON (1967); 4, Toxodontidae.
FAUNA OF CHILE AND THE EARLY STAGES OF “MODERNIZATION” OF SOUTH AMERICA MAMMAL FAUNAS 201
Arq. Mus. Nac., Rio de Janeiro, v.66, n.1, p.191-211, jan./mar.2008
The cladogram resembled CIFELLI’s (1993), however,
in that Eomorphippus (E. obscurus) was the nearest
outgroup to this larger clade including some
notohippids plus toxodontids. If taxa such as
Plexotemnus, Pampahippus, and Puelia are included
in the Notohippidae, as advocated by BOND & LÓPEZ
(1993), these taxa are positioned as outgroups to a
clade formed by leontiniids plus traditionally
recognized notohippids and toxodontids (SHOCKEY,
1997a, b). In other words, notohippids are distributed
across a variety of anatomically advanced toxodontian
groups (Fig.6). Our research group is working to
clarify relationships among these later diverging
toxodontians, but for the purposes of the current
discussion we employ BOND & LÓPEZ’s (1993) broader
conception of Notohippidae.
After archaeohyracids, notohippids are the most
diverse group at Tinguiririca, with at least four
species present (WYSS et al., 1994, 2005; FLYNN et
al., 2003). These include two relatively basal
notohippids (an undescribed species (Fig.2C) and
cf. “Eomorphippus pascuali) and two more
advanced notohippids (both new species of
Eomorphippus, one close to E. obscurus) (WYSS et
al., 1994, 2005). E. obscurus occurs at Cañadón
Blanco (SIMPSON, 1967; FLYNN et al., 2003) and both
E.” pascuali and E. obscurus have been collected
from the APS level at Gran Barranca (BOND et al.,
1996). Puelia, an otherwise Mustersan taxon,
possibly occurs at Rocas Bayas along with another
indeterminate notohippid (BOND et al., 1997).
Species of Eomorphippus share the derived presence
of hypsodont molars and incisors and are useful
taxa for recognition of Tinguirirican faunas (WYSS
et al., 1994, 2005; FLYNN et al., 2003).
The earliest notohippids are Casamayoran in age and
include Pampahippus from the lower part of the
Lumbrera Formation of Salta, Argentina (BOND &
LÓPEZ, 1993) and Plexotemnus from the Gran Barranca
(SIMPSON, 1967). More refined age estimates for these
taxa are lacking since the Lumbrera Formation is
poorly constrained (BABOT et al., 2002; HONGN et al.,
2007) and the stratigraphic position of Plexotemnus
at the Gran Barranca is unknown (CIFELLI, 1985a).
According to BOND & LÓPEZ (1993), Pampahippus,
Plexotemnus, and Puelia appear to represent a
structural lineage between basal toxodontians and
later-occurring notohippids such as Eomorphippus;
accordingly, northwest Argentina has been proposed
as the center of diversification for the group.
Notohippids are diverse and abundant in Deseadan
faunas (CIFELLI, 1985b); besides the classic localities
in Patagonia, they also occur in the Fray Bentos
Formation, Uruguay (REGUERO et al., 2003b); Salla,
Bolivia (SHOCKEY, 1997a, b); new sites in the Abanico
Formation, central Chile; and the Tremembé
Formation, southeast Brazil (SORIA & ALVARENGA,
1989). They have not been reported from Moquegua
or Santa Rosa in Perú (SHOCKEY et al., 2004, 2006)
but this may be attributable to sparse sampling.
LEONTINIIDAE
Leontiniids are rare during the Tinguirirican; only
a single specimen has been collected from the type
locality, and it has not yet been identified more
precisely (FLYNN et al., 2003). The Tinguirirican
leontiniid represented the earliest record of the
group until the recent report of a new species
(Coquenia bondi) from the ?Mustersan upper part
of the Lumbrera Formation of northwest Argentina
(POWELL & DERACO, 2003; DERACO et al., in press). A
specimen from a new pre-Tinguirirican Chilean
locality may comparably extend the group’s range
in Chile. Leontiniids are more diverse and
apparently much more abundant in the Deseadan,
having been reported from Bolivia (SHOCKEY, 1997a,
2005), southeast Brazil (PAULA COUTO, 1983), and
Uruguay/northeast Argentina (REGUERO et al.,
2003b), in addition to Patagonia (LOOMIS, 1914;
CHAFFEE, 1952; MARSHALL et al., 1986). Some of these
Deseadan specimens even include complete
skeletons (SIMPSON, 1934; CHAFFEE, 1952).
Leontiniids also are diverse and abundant at the
locality of La Cantera at Gran Barranca, but the
precise age of this Oligocene fauna is unclear (LÓPEZ
et al., 2005). Fragmentary material from the
Paleogene locality of Santa Rosa, Perú, may pertain
to a leontiniid (SHOCKEY et al., 2004); as noted above,
this likely represents an Oligocene occurrence.
In the Neogene, the record of leontiniids is much
patchier. Although Colpodon is characteristic of the
early Miocene Colhuehuapian SALMA (AMEGHINO,
1902b; SIMPSON, 1932b, 1935b; BORDAS, 1939;
MARSHALL et al., 1983) the group is thereafter absent
from the Patagonian record. The last occurrence is
in the middle Miocene La Venta Fauna of Colombia
(VILLARROEL & COLWELL DANIS, 1997). Based on this
distribution, it appears that leontiniids experienced
a significant contraction and/or shift in their
geographic range by the late early Miocene. Testing
this hypothesis will require additional low and
middle latitude faunas, especially from the early and
middle Miocene. Moderately well-sampled later
Cenozoic faunas from the middle latitudes of Chile
202 D.A.CROFT, J.J.FLYNN & A.R.WYSS
Arq. Mus. Nac., Rio de Janeiro, v.66, n.1, p.191-211, jan./mar.2008
and Bolivia appear to lack evidence of leontiniids
(CROFT et al., 2004, 2007; CROFT, 2007). A recently
identified leontiniid from the Miocene Laguna del
Laja region of south-central Chile (WYSS et al., 2003;
WERTHEIM et al., 2004, 2005; FLYNN et al., in press)
may provide important information on the
geographic and temporal distribution of leontiniids,
depending on resolution of its precise age and
stratigraphic position.
OTHER UNGULATE GROUPS
In addition to the groups discussed above, the presence
or absence of several less diverse groups from the
Tinguirirican merit comment. Among notoungulates,
no henricosborniids, archaeopithecids, or
oldfieldthomasiids have been reported from this
interval; all of these groups are restricted to Eocene
and older localities (SIMPSON, 1948, 1967; MARSHALL
et al., 1983). Given the abundance and diversity of
oldfieldthomasiids at Divisadero Largo and the
number of Tinguirirican faunas that have been
sampled, it seems likely that those from Divisadero
Largo predate the Tinguirirican (WYSS et al., 1994;
FLYNN et al., 2003). No toxodontids occur in the
Tinguirirican, apparently constraining their origin
to the small interval of time between the
Tinguirirican and the Deseadan.
Ungulates other than notoungulates constitute only
a minor component of Tinguirirican faunas.
Astrapotheres (including trigonostylopids) range
from the Riochican through the middle Miocene
(SIMPSON, 1935b, 1967; CIFELLI, 1985b) and are only
represented during the Tinguirirican by
Isolophodon at Cañadón Blanco (ROTH, 1903; FLYNN
et al., 2003). Litopterns exhibit a pattern similar to
that of astrapotheres; the sole representative of the
clade during the Tinguirirican is the proterotheriid
Anisolambda from Cañadón Blanco (ROTH, 1903).
Anisolambda is a particularly long-ranging taxon,
occurring in Riochican through Deseadan faunas
(CIFELLI, 1983).
A single indaleciine has been reported from
Tinguiririca (WYSS et al., 1994; FLYNN et al., 2003);
although traditionally allied with litopterns, several
analyses have cast doubt on this taxonomic
affiliation (CIFELLI, 1983, 1993; CIFELLI & SORIA, 1983;
WYSS et al., 1994). Regardless of its proper higher-
level relationships, the form from Tinguiririca is most
similar to Indalecia grandis from the Casamayoran
lower part of the Lumbrera Formation of Salta,
Argentina (BOND & VUCETICH, 1983; WYSS et al., 1994).
The close similarity of this taxon to a species from
northwest Argentina parallels geographic patterns
seen other Tinguirirican ungulate groups such as
basal interatheriids and notostylopids (see above).
TINGUIRIRICA PALEOENVIRONMENT
Multiple lines of evidence (faunal hypsodonty,
cenograms, rainfall estimates via ecological
diversity analysis) have previously been used to
suggest that the Tinguiririca Fauna represents
the earliest ‘open’ habitat (likely grassland/
wooded grassland) community in South America
(FLYNN et al., 2003). Although these lines of
evidence are not entirely independent (e.g., diet
and body mass factor into ecological diversity
analyses), their congruence increases confidence
in the resultant habitat reconstruction. An open
question, however, is the degree to which unusual
aspects of the Tinguiririca Fauna (and/or South
American mammalian paleofaunas in general,
relative to those on other continents) might be
driving these patterns. For example, is it possible
that the high proportion of hypsodont ungulates
at Tinguiririca reflects not the consumption of
siliceous phytolith-bearing open habitat
vegetation (i.e., grasses), but rather exogenous
grit produced by nearby volcanoes, as suggested
by PASCUAL & ORTIZ JAUREGUIZAR (1990)? Or might
notoungulates have had some intrinsic tendency
to increase the height of their cheek teeth
regardless of the environment, as implied by
SIMPSON (1980)? With these questions in mind,
we undertook an even more conservative
ecological diversity analysis (EDA) in which the
influence of hypsodonty would be minimized.
As in our previous ecological diversity analysis, we
coded each Tinguiririca taxon for three variables:
diet, locomotor style, and body mass (FLYNN et al.,
2003). For comparative purposes, we also coded
mammals from sixteen modern Neotropical faunas
(from KAY & MADDEN, 1997) for the same variables.
In the present analysis, however, we coded these
attributes differently. We used far broader, more
conservative dietary categories than in our previous
analysis, to minimize the chance of misinterpreting
diet based on tooth crown height (hypsodonty);
these five dietary categories included folivore (a
combination of browser, grazer, and mixed feeder
categories), frugivore, insectivore, omnivore, and
carnivore. Our locomotor categories also were quite
broad; species were classified as either terrestrial
or arboreal, with the latter category including
scansorial and semi-arboreal species. In contrast,
FAUNA OF CHILE AND THE EARLY STAGES OF “MODERNIZATION” OF SOUTH AMERICA MAMMAL FAUNAS 203
Arq. Mus. Nac., Rio de Janeiro, v.66, n.1, p.191-211, jan./mar.2008
we used narrower body mass categories (following
TOWNSEND, 2004) which permitted greater
discrimination among taxa than the six categories
used previously, but still buffered against small
errors inherent in estimating body masses of extinct
taxa (DAMUTH & MACFADDEN, 1990; CROFT, 2001). For
details of paleobiological inferences, see FLYNN et
al. (2003).
The proportion of taxa in each category noted above
(e.g., number of frugivores/total number of species)
was calculated for Tinguiririca and each modern
fauna. These proportions were then arcsine
transformed to normalize the data (SOKAL & ROHLF,
1995) and seven of the original nineteen categories
were used in a discriminant function analysis
(DFA); the seven categories employed were those
demonstrated by TOWNSEND (2004) to be statistically
correlated with habitat type in her dataset of
modern South American mammal faunas. The DFA
was performed using SPSS (SPSS Inc.) on an Apple
G4 computer; the prior probabilities for the three
habitat types (open, mixed, closed) were considered
equal. The resultant two functions correctly
classified 15 of 16 modern faunas by habitat type
and classified Tinguiririca as an open habitat fauna
with 100% probability, thus strongly supporting
previous habitat interpretations (WYSS et al., 1994;
FLYNN et al., 2003). The raw percentages used in
our analysis are provided in table 2 and the
structure matrix of the two functions is provided
in table 3.
FUNCTION
1
FUNCTION
2
Frugivorous -0.023 -0.256
Folivorous 0.106 0.252
Insectivorous -0.148 0.423
Mass Class VII 0.332 -0.626
Mass Class VIII -0.090 0.468
Arboreal -0.147 -0.498
FAUNA HABITAT FRUGIVORES FOLIVORES INSECTIVORES MASS
CLASS
VII
MASS
CLASS
VIII
ARBOREAL TERRESTRIAL
Guatopo Mixed 42.5 15.0 20.0 10.0 2.5 60.0 40.0
Masaguaral Open 37.9 17.2 13.8 13.8 3.4 55.2 44.8
Puerto Páez Open 45.8 20.8 4.2 12.5 0.0 45.8 54.2
Puerto Ayacuchi Mixed 53.3 13.3 15.6 4.4 4.4 57.8 42.2
Esmeralda Closed 60.6 9.1 13.6 6.1 3.0 69.7 30.3
Manaus Closed 49.0 13.7 17.6 7.8 5.9 62.7 37.3
Belém Closed 35.5 14.5 19.4 8.1 4.8 58.1 41.9
Caatingas Mixed 19.0 23.8 28.6 4.8 4.8 38.1 61.9
Federal District Mixed 39.4 19.7 19.7 3.0 4.5 37.9 62.1
Acurizal Mixed 35.7 19.0 11.9 4.8 11.9 42.9 57.1
Chaco Mixed 19.4 27.8 25.0 0.0 11.1 30.6 69.4
Transitional
Forest Closed 20.0 22.2 24.4 2.2 4.4 42.2 57.8
Low Montane Closed 34.6 26.9 3.8 3.8 0.0 46.2 53.8
Cocha Cashu Closed 52.9 14.3 14.3 8.6 5.7 67.1 32.9
Rio Cenapa Closed 43.5 12.9 17.7 8.1 4.8 61.3 38.7
Ecuador Tropical Closed 43.9 11.0 18.3 7.3 3.7 63.4 36.6
Tinguiririca Unknown 12.0 80.0 4.0 4.0 8.0 12.0 88.0
TABLE 3. Percentages of mammal species in each of seven macroecological categories for Tinguiririca and sixteen modern
Neotropical faunas from KAY & MADDEN (1997).
TABLE 2. Structure coefficients (pooled within-groups
correlations between discriminating variables and
standardized canonical discriminant functions) for DFA
by habitat type.
The proportion of terrestrial taxa was not used
in either discriminant function.
204 D.A.CROFT, J.J.FLYNN & A.R.WYSS
Arq. Mus. Nac., Rio de Janeiro, v.66, n.1, p.191-211, jan./mar.2008
Although the DFA unequivocally classifies
Tinguiririca as an open habitat, the Mahalanobis
distance between it and the open habitats centroid
far exceeds that for any modern fauna (Fig.7). In
other words, Tinguiririca is more similar to a modern
savanna than a modern forest, but it still differs
markedly from the sixteen modern faunas used in
the DFA. This is best illustrated by the extremely
high proportion of folivorous species at Tinguiririca
(close to three times that of any modern fauna) and
the equally low proportion of arboreal taxa (less than
one third that of any modern fauna) (Tab.3). Given
these numbers, it is obvious why the fauna is
classified as open habitat, but the non-analog aspect
of the fauna is also evident.
There are, of course, several potential explanations
for the uniqueness of Tinguiririca. Given that
Tinguiririca is a fossil fauna, the possibility of
taphonomic bias cannot be ruled out. What such bias
might include is unclear, however, since taxa of many
sizes are present at Tinguiririca and the preservation
of specimens is generally excellent. Moreover, the
number of small arboreal
frugivores missing from the
fauna due to taphonomic bias
would have to be quite large
to result in a fauna similar to
any existing today in South
America. Perhaps most
compelling is the great
similarity between the results
obtained in this study and
those obtained by CROFT &
TOWNSEND (2005) in their EDA
of the late early Miocene Santa
Cruz Fauna of Argentina; if
taphonomic bias were at
work, it would have to
produce similar effects despite
considerable temporal,
geographic, and depositional
differences between Santa
Cruz and Tinguiririca. This
seems implausible.
Errors in ecological inter
pretations of extinct taxa could
also bias this type of
analysis. Since we used very
conservative ecomorphological
categories, it is difficult to
imagine systematic errors that
would result in drastically
different locomotor or dietary
interpretations for the taxa under consideration. That
is not to say that such errors are impossible; perhaps
some of the smaller notoungulates (or even some of
the larger ones) were less folivorous and more
frugivorous. But as noted above, such
misinterpretations would have to be prevalent to
significantly alter habitat inferences.
The most reasonable conclusion is that middle
Cenozoic South American faunas simply were
structured very differently than modern South
American communities (e.g., CROFT, 2001). This
should not be surprising given the great differences
in taxonomic composition (at high taxonomic levels)
between most fossil and modern faunas, and the
dramatic changes in endemism and interchange
through the Cenozoic in South America. Such
differences have also been observed in North
American fossil faunas (JANIS et al., 2002), but not
necessarily to the same degree. Even though the
differences between modern and fossil faunas
necessarily limit confidence in paleohabitat
interpretations, the evidence presented here
Fig.7- Bivariate plot of Tinguiririca and 16 modern Neotropical faunas based on the
first two functions from the discriminant analysis described in the text. Habitats are
plotted by predicted group membership (i.e., habitat type), with Tinguiririca identified.
The open box represents Puerto Ayacucho, a mixed habitat misidentified as a closed
habitat; this was the only misidentified modern habitat.
FAUNA OF CHILE AND THE EARLY STAGES OF “MODERNIZATION” OF SOUTH AMERICA MAMMAL FAUNAS 205
Arq. Mus. Nac., Rio de Janeiro, v.66, n.1, p.191-211, jan./mar.2008
combined with that of FLYNN et al. (2003) provides
compelling evidence for the presence of open
habitats in South America by the earliest Oligocene.
CONCLUSIONS
Faunas dominated by hypsodont herbivores appear
significantly earlier in South America than
elsewhere in the world (WYSS et al., 1994; FLYNN &
WYSS, 1998; FLYNN et al., 2003). This “precocious
hypsodonty” has long been recognized for Deseadan
faunas (e.g., PATTERSON & PASCUAL, 1968) but has
only recently been demonstrated to apply to the
older Tinguirirican SALMA as well (WYSS et al., 1990,
1993, 1994; FLYNN et al., 2003). The high degree of
hypsodonty seen in many Tinguirirican species
reflects a dramatic “modernization” of South
American mammal communities compared to those
immediately preceding this time, and may reflect
environmental effects of the Eocene-Oligocene
Transition (WOLFE, 1971; PROTHERO & BERGGREN,
1992). The results of EDA provide additional
evidence that open habitats prevailed at these
latitudes in South America by earliest Oligocene
time, this despite the intriguing recent proposal
that regional climate (i.e., continental temperatures)
in Patagonia did not change substantially across
the Eocene-Oligocene Transition (KOHN et al., 2004).
In addition to documenting important changes in
hypsodonty on a faunal level, Tinguirirican faunas
have clarified other aspects of dental evolution in
various notoungulate clades. A dramatic jump in
hypsodonty (without the attainment of hypselodonty)
is synchronous across several lineages of
notoungulates (viz., notohippids, interatheriids,
archaeohyracids) by the Tinguirirican. Hypselodonty
(i.e., “euhypsodonty”), in contrast, appears to have
originated among notoungulates in two pulses: by
the Tinguirirican in hegetotheriids and
mesotheriids, and by the Deseadan (late Oligocene)
in interatheriids and toxodontids. Although
hypselodont taxa dominate Neogene faunas, it is the
very hypsodont taxa that predominate during the
Tinguirirican; early mesotheriids and hegetotheriids
are represented by very limited material, and
toxodontids and hypselodont interatheriines are not
recorded until the Deseadan. Such a pattern
suggests that these dentally advanced members of
“primitive” lineages (e.g., archaeohyracids,
notohippids) enjoyed some type of competitive
superiority and/or ecological incumbency during the
early Oligocene and that the later success of
hypselodont taxa may be less attributable to tooth
crown height than previously believed.
Biogeographic interpretations based on
Tinguirirican faunas are limited by the lack of
corresponding faunas from northern South
America and by the uncertain age(s) of the species
from Divisadero Largo. Still, some trends are worth
noting. The ungulate fauna of Tinguiririca
demonstrates affinities to both classical localities
in Patagonia and more recently uncovered localities
in northwest Argentina (WYSS et al., 1994; FLYNN et
al., 2003). This mixed pattern thus provides
evidence for a mild degree of faunal provinciality
during this interval, but not one reflecting dramatic
ecological or geographic barriers. Absences of
certain Tinguirirican-aged ungulates at Tinguiririca
stem either from sampling or regional differences;
study of additional new Tinguirirican faunas in
central Chile (e.g., Cachapoal) should help
discriminate between these two alternatives. Given
the small size of collections from most Patagonian
localities, absences of various Tinguirirican
ungulates at Cañadón Blanco and the APS level of
the Gran Barranca should be accorded little
biogeographic significance at this time. Increased
sampling of these faunas promises to clarify
biogeographic patterns during this important
interval of mammal evolution.
In contrast to the overall resemblance among
Chilean and Patagonian Tinguirirican faunas, the
faunal differences between Tinguiririca and
Divisadero Largo are striking, especially given their
close geographic proximity (Fig.3). This disparity
is evident in both ecomorphological and taxonomic
contexts; Tinguiririca is dominated by hypsodont
taxa such as archaeohyracids, interatheriids, and
notohippids, whereas brachydont taxa such as
oldfieldthomasiids predominate at Divisadero
Largo (SIMPSON et al., 1962). No taxon is shared at
the specific or generic level between the two
faunas, and none of the most abundant families
(i.e., the four noted above) is recorded at both.
The marked disparity between Divisadero Largo
and earliest Oligocene Tinguirirican localities from
central Chile is consistent with the recent
suggestion that the former is a temporally mixed
assemblage (CERDEÑO et al., 2005; LÓPEZ &
MANASSERO, 2006). Our review of Tinguirirican
notoungulates suggests that Divisadero Largo
does not sample the Tinguirirican, but rather
includes many pre-Tinguirirican species and two
likely post-Tinguirirican ones.
206 D.A.CROFT, J.J.FLYNN & A.R.WYSS
Arq. Mus. Nac., Rio de Janeiro, v.66, n.1, p.191-211, jan./mar.2008
ACKNOWLEDGMENTS
We thank Marcelo Reguero and Lílian Bergqvist for
inviting us to participate in the symposium “Origin,
Evolution and Biogeography of Gondwanan
Mammals” at the II Congreso Latinoamericano de
Paleontología de Vertebrados. We thank M. Reguero
and two anonymous reviewers for providing
constructive feedback on this manuscript prior to
publication. We gratefully acknowledge the support
of the U.S. National Science Foundation (DEB
9020213, 9318126, 9317943), Chilean FONDECYT
(Grant Number 1970736), and our home
institutions. Our work has had the strong backing
of the Museo Nacional de Historia Natural and the
Consejo de Monumentos Nacionales, Santiago,
Chile. Daniel Frassinetti has been particularly
instrumental in facilitating that support. We
especially thank R. Charrier for his deep
involvement in many facets of our work in Chile.
REFERENCES
AMEGHINO, F., 1901. Notices préliminaires sur des
ongulés nouveaux des terrains crétacés de Patagonie.
Boletín de la Academia Nacional de Ciencias de
Córdoba, 16:350-426.
AMEGHINO, F., 1902a. Notices préliminaires sur des
mamifères nouveaux des terrains crétacés de Patagonie.
Boletín de la Academia Nacional de Ciencias de
Córdoba, 17:5-70.
AMEGHINO, F., 1902b. Première contribution à la
connaissance de la faune mammalogique des couches à
Colpodon. Boletín de la Academia Nacional de Ciencias
de Córdoba, 17:71-138.
BABOT, M.J.; POWELL, J.E. & MUIZON, C.D., 2002.
Callistoe vincei, a new Proborhyaenidae (Borhyaenoidea,
Metatheria, Mammalia) from the Early Eocene of
Argentina. Geobios, 35:615-629.
BERGQVIST, L.P. & RIBEIRO, A.M., 1998. A
paleomastofauna das bacias Eoterciárias brasileiras e
sua importância na datação das bacias de Itaboraí e
Taubaté. In: CASADÍO, S. (Ed.) Paleógeno de América
del Sur y de la Península Antártica. Buenos Aires:
Publicación Especial 5, Asociación Paleontológica
Argentina. p.19-34.
BOND, M., 1986. Los ungulados fósiles de Argentina:
evolución y paleoambientes. In: CONGRESO
ARGENTINO DE PALEONTOLOGÍA Y
BIOESTRATIGRAFÍA, 4., 1986, Mendoza. Actas…, 2.
Mendoza. p.173-185.
BOND, M., 1991. Sobre las capas de supuesta edad
Divisaderense en los “Estratos de Salla,” Bolivia. In:
SUÁREZ-SORUCO, R. (Ed.) Fósiles y Facies de Bolivia
- Vol. I Vertebrados. Santa Cruz: Yacimientos
Petrolíferos Fiscales Bolivianos. p.701-705.
BOND, M. & LÓPEZ, G., 1993. El primer Notohippidae
(Mammalia, Notoungulata) de la Formación Lumbrera
(Grupo Salta) del noroeste Argentino. Consideraciones
sobre la sistemática de la familia Notohippidae.
Ameghiniana, 30:59-68.
BOND, M. & LÓPEZ, G., 1995. Los mamíferos de la
Formación Casa Grande (Eoceno) de la provincia de
Jujuy, Argentina. Ameghiniana, 32:301-309.
BOND, M.; LÓPEZ, G. & REGUERO, M., 1996.
“Astraponoteén plus supérieur” of Ameghino: another
interval in the Paleogene record of South America.
Journal of Vertebrate Paleontology, 16:23A.
BOND, M.; LÓPEZ, G. & REGUERO, M., 1997. Rocas
Bayas, una localidad fosilífera Paleógena de la Provincia
de Río Negro, República Argentina. Ameghiniana,
34:533.
BOND, M.; LÓPEZ, G.; REGUERO, M.A.; SCILLATO-
YANÉ, G.J. & VUCETICH, M.G., 1998. Los mamíferos
de la Formación Fray Bentos (edad mamífero
Deseadenese, Oligocene superior?) de las provincias de
Corrientes y Entre Ríos, Argentina. In: CASADÍO, S. (Ed.)
Paleógeno de América del Sur y de la Península
Antártica. Buenos Aires: Publicación Especial 5,
Asociación Paleontológica Argentina. p.41-50.
BOND, M. & VUCETICH, M.G., 1983. Indalecia
grandensis gen. et sp. nov. del Eoceno temprano del
noroeste argentino, tipo de una nueva Subfamilia de los
Adianthidae (Mammalia, Litopterna). Revista de la
Asociación Geológica Argentina, 38:107-117.
BORDAS, A.F., 1939. Diagnosis sobre algunos mamíferos
de las capas con Colpodon del Valle del Río Chubut
(República Argentina). Physis, 14:413-433.
CAMPBELL, K.E., JR. (Ed.), 2004. The Paleogene
Mammalian Fauna of Santa Rosa, Amazonian Peru.
Los Angeles: Natural History Museum of Los Angeles
County. 163p.
CAMPBELL, K.E.; FRAILEY, C.D. & ROMERO-PITTMAN,
L., 1996. The first Paleogene fauna from the Amazon
Basin and its bearing on the first occurrence of rodents
in South America. Journal of Vertebrate Paleontology,
16:25A.
CAMPBELL, K.E.; FRAILEY, C.D. & ROMERO-PITTMAN,
L., 2004. The Paleogene Santa Rosa local fauna of
Amazonian Perú: geographic and geologic setting.
Natural History Museum of Los Angeles County,
Science Series, 40:3-14.
FAUNA OF CHILE AND THE EARLY STAGES OF “MODERNIZATION” OF SOUTH AMERICA MAMMAL FAUNAS 207
Arq. Mus. Nac., Rio de Janeiro, v.66, n.1, p.191-211, jan./mar.2008
CARLINI, A.A.; MADDEN, R.H.; VUCETICH, M.G.; BOND,
M.; LÓPEZ, G.; REGUERO, M. & SCARANO, A., 2005.
Mammalian biostratigraphy and biochronology at Gran
Barranca: the standard reference section for the continental
middle Cenozoic of South America. In: CONGRESO
GEOLÓGICO ARGENTINO, 15., 2005, El Calafate. Actas…
El Calafate. CD-ROM, Artículo Nº 807, 2p.
CERDEÑO, E. & BOND, M., 1998. Taxonomic revision
and phylogeny of Paedotherium and Tremacyllus
(Pachyrukhinae, Hegetotheriidae, Notoungulata) from the
late Miocene to Pleistocene of Argentina. Journal of
Vertebrate Paleontology, 18:799-811.
CERDEÑO, E.; LÓPEZ, G. & REGUERO, M., 2005. Sobre
un Mesotheriidae (Mammalia, Notoungulata) de la
Formación Mariño y sus implicancias sobre la identidad
de la “Edad Mamífero” Divisaderense. Ameghiniana,
42:21R.
CHAFFEE, R.G., 1952. The Deseadan vertebrate fauna
of the Scarritt Pocket, Patagonia. Bulletin of the
American Museum of Natural History, 98:509-562.
CIFELLI, R.L., 1983. The origin and affinities of the South
American Condylarthra and early Tertiary Litopterna
(Mammalia). American Museum Novitates, 2772:1-49.
CIFELLI, R.L., 1985a. Biostratigraphy of the
Casamayoran, Early Eocene, of Patagonia. American
Museum Novitates, 2820:1-26.
CIFELLI, R.L., 1985b. South American ungulate
evolution and extinction. In: STEHLI, F.G. & WEBB, S.D.
(Eds.) The Great American Biotic Interchange. New
York: Plenum Press. p.249-266.
CIFELLI, R.L., 1993. The phylogeny of the native South
American ungulates. In: SZALAY, F.S.; NOVACEK, M.J.
& MCKENNA, M.C. (Eds.) Mammal Phylogeny:
Placentals. New York: Springer-Verlag. p.195-216.
CIFELLI, R.L. & SORIA, M.F., 1983. Systematics of the
Adianthidae (Litopterna, Mammalia). American Museum
Novitates, 2771:1-25.
COOMBS, M.C., 1983. Large mammalian clawed
herbivores: a comparative study. Transactions of the
American Philosophical Society, New Series, 73:1-96.
CROFT, D.A., 1999. Placentals: South American ungulates.
In: SINGER, R. (Ed.) Encyclopedia of Paleontology.
Chicago: Fitzroy-Dearborn Publishers. p.890-906.
CROFT, D.A., 2000. Archaeohyracidae (Mammalia,
Notoungulata) from the Tinguiririca Fauna, central
Chile, and the evolution and paleoecology of South
American mammalian herbivores. Dissertation (Ph.D.),
The University of Chicago, Chicago. Unpublished.
CROFT, D.A., 2001. Cenozoic environmental change in
South American as indicated by mammalian body size
distributions (cenograms). Diversity and Distributions,
7:271-287.
CROFT, D.A., 2007. The middle Miocene (Laventan)
Quebrada Honda Fauna, southern Bolivia, and a description
of its notoungulates. Palaeontology, 50:277-303.
CROFT, D.A. & ANAYA, F., 2006. A new middle Miocene
hegetotheriid (Notoungulata: Typotheria) and a phylogeny
of the Hegetotheriidae. Journal of Vertebrate
Paleontology, 26:387-399.
CROFT, D.A.; BOND, M.; FLYNN, J.J.; REGUERO, M.A.
& WYSS, A.R., 2003a. Large archaeohyracids
(Typotheria, Notoungulata) from central Chile and
Patagonia including a revision of Archaeotypotherium.
Fieldiana, 49:1-38.
CROFT, D.A.; FLYNN, J.J. & WYSS, A.R., 2003b.
Diversification of mesotheriids (Mammalia:
Notoungulata: Typotheria) in the middle latitudes of
South America. Journal of Vertebrate Paleontology,
23:43A.
CROFT, D.A.; FLYNN, J.J. & WYSS, A.R., 2004.
Notoungulata and Litopterna of the early Miocene Chucal
Fauna, northern Chile. Fieldiana, 50:1-52.
CROFT, D.A.; FLYNN, J.J. & WYSS, A.R., 2007. A new
basal glyptodontid and other Xenarthra of the early
Miocene Chucal Fauna, northern Chile. Journal of
Vertebrate Paleontology, 27:780-796.
CROFT, D.A. & TOWNSEND, K.A., 2005. Inferring habitat
for the late early Miocene Santa Cruz Fauna (Santa Cruz
Province, Argentina) using ecological diversity analysis.
Journal of Vertebrate Paleontology, 25:48A.
DAMUTH, J. & MACFADDEN, B.J. (Eds.), 1990. Body
Size in Mammalian Paleobiology: Estimation and
Biological Implications. Cambridge: Cambridge
University Press. 409p.
DERACO, M.V.; POWELL, J.E. & LÓPEZ, G., in press.
Primer leontínido (Mammalia, Notoungulata) de la
Formación Lumbrera (Subgrupo Santa Bárbara, Grupo
Salta – Paleógeno) del Noroeste Argentino. Ameghiniana.
DOZO, M.T.; REGUERO, M. & CERDEÑO, E., 2000.
Medistylus dorsatus (Ameghino, 1903), un
Hegetotheriidae Pachyrukhinae (Mammalia,
Notoungulata) del Deseadense de la provincia de Chubut,
Argentina. Ameghiniana, 37:24R.
FLYNN, J.J.; CHARRIER, R.; CROFT, D.A.; GANS, P.B.;
HERRIOTT, T.M.; WERTHEIM, J.A. & WYSS, A.R., in
press. Chronologic implications of new Miocene
mammals from the Cura-Mallín and Trapa Trapa
formations, Laguna del Laja area, south central Chile.
Journal of South American Earth Sciences.
208 D.A.CROFT, J.J.FLYNN & A.R.WYSS
Arq. Mus. Nac., Rio de Janeiro, v.66, n.1, p.191-211, jan./mar.2008
FLYNN, J.J.; CROFT, D.A.; CHARRIER, R.; HÉRAIL, G.
& WYSS, A.R., 2002. The first Cenozoic mammal fauna
from the Chilean Altiplano. Journal of Vertebrate
Paleontology, 22:200-206.
FLYNN, J.J.; CROFT, D.A.; CHARRIER, R. & WYSS, A.R.,
2005b. New Mesotheriidae (Mammalia, Notoungulata,
Typotheria), geochronology and tectonics of the Caragua
area, northernmost Chile. Journal of South American
Earth Sciences, 19:55-74.
FLYNN, J.J.; CROFT, D.A.; HITZ, R. & WYSS, A.R.,
2005a. The Tapado Fauna (Casamayoran SALMA),
Abanico Formation, Tinguiririca Valley, central Chile.
Journal of Vertebrate Paleontology, 25:57A.
FLYNN, J.J. & SWISHER, C.C., III, 1995. Cenozoic South
American Land Mammal Ages: Correlation to global
geochronologies. In: BERGGREN, W.A., KENT, D.V.,
AUBRY, M.-P. & HARDENBOL, J. (Eds.) Geochronology,
Time Scales, and Global Stratigraphic Correlation.
Tulsa: SEPM (Society for Sedimentary Geology) Special
Publication No. 54. p.317-333.
FLYNN, J.J. & WYSS, A.R., 1998. Recent advances in
South American mammalian paleontology. Trends in
Ecology and Evolution, 13:449-454.
FLYNN, J.J. & WYSS, A.R., 2004. A polydolopine
marsupial skull from the Cachapoal Valley, Andean Main
Range, Chile. Bulletin of the American Museum of
Natural History, 285:80-92.
FLYNN, J.J.; WYSS, A.R. & CHARRIER, R., 2007. South
America’s missing mammals. Scientific American,
5:68-75.
FLYNN, J.J.; WYSS, A.R.; CROFT, D.A. & CHARRIER,
R., 2003. The Tinguiririca Fauna, Chile: biochronology,
paleoecology, biogeography, and a new earliest Oligocene
South American Land Mammal “Age”. Palaeogeography,
Palaeoclimatology, Palaeoecology, 195:229-259.
HITZ, R.; FLYNN, J.J. & WYSS, A.R., 2006. New Basal
Interatheriidae (Typotheria, Notoungulata, Mammalia)
from the Paleogene of Central Chile. American Museum
Novitates, 3520:1-32.
HITZ, R.; REGUERO, M.; WYSS, A.R. & FLYNN, J.J.,
2000. New interatheriines (Interatheriidae,
Notoungulata) from the Paleogene of central Chile and
southern Argentina. Fieldiana, 42:1-26.
HOFFSTETTER, R., 1969. Un primate de l’Oligocène
infèrieurran sudamerica: Branisella boliviana gen. et sp.
nov. Comptes Rendus de la Académie des Sciences,
269:434-437.
HONGN, F.; DEL PAPA, C.; POWELL, J.; PETRINOVIC,
I.; MON, R. & DERACO, V., 2007. Middle Eocene
deformation and sedimentation in the Puna-Eastern
Cordillera transition (23°–26°S): control by preexisting
heterogeneities on the pattern of initial Andean
shortening. Geology, 35:271-274.
JANIS, C.M.; DAMUTH, J. & THEODOR, J.M., 2002.
The origins and evolution of the North American
grassland biome: the story from the hoofed mammals.
Palaeogeography, Palaeoclimatology, Palaeoecology,
177:183-198.
KAY, R.F. & MADDEN, R.H., 1997. Mammals and
rainfall: paleoecology of the middle Miocene at La Venta
(Colombia, South America). Journal of Human
Evolution, 32:161-199.
KAY, R.F.; MADDEN, R.H.; CIFELLI, R.L. & FLYNN, J.J.
(Eds.), 1997. Vertebrate Paleontology in the Neotropics:
the Miocene Fauna of La Venta, Colombia. Washington,
D.C.: Smithsonian Institution Press. 592p.
KAY, R.F.; MADDEN, R.H.; VUCETICH, M.G.; CARLINI,
A.A.; MAZZONI, M.M.; RE, G.H.; HEIZLER, M. &
SANDEMAN, H., 1999. Revised geochronology of the
Casamayoran South American land mammal age:
climatic and biotic implications. Proceedings of the
National Academy of Sciences of the United States
of America, 96:13235-13240.
KOHN, M.J.; CARLINI, A.A.; JOSEF, J.A.; KAY, R.F.;
MADDEN, R.H. & VUCETICH, M.G., 2004. Climate
stability across the Eocene-Oligocene transition,
southern Argentina. Geology, 32:621-624.
KRAMARZ, A.; GARRIDO, A.C.; RIBEIRO, A.M. & ORTIZ,
R., 2004. Nuevos registros de vertebrados fósiles de la
Formación Chichinales, Mioceno Temprano de la
provincia de Río Negro. Ameghiniana, 41:53R.
LINARES, O.J., 2004. Bioestratigrafía de la fauna de
mamíferos de las formaciones Socorro, Urumaco y
Codore (Miocene medio - Plioceno temprano) de la región
de Urumaco, Falcon, Venezuela. Paleobiología
Neotropical, 1:1-26.
LINARES, E.; PASCUAL, R. & TIMONIERI, A.J., 1960.
La edad de los sedimentos terciarios del valle de Punilla,
provincia de Córdoba, y la presencia de ‘Eohyrax rusticus’
Ameghino en los mismos. Revista de la Asociación
Geológica Argentina, 15:191-212.
LOOMIS, F.B., 1914. The Deseado Formation of
Patagonia. Concord: Runford Press. 232p.
LÓPEZ, G.M., 1997. Paleogene faunal assemblage from
Antofagasta de la Sierra (Catamarca Province, Argentina).
Palaeovertebrata, 26:61-81.
LÓPEZ, G.M., 2002. Redescripción de Ethegotherium
carettei (Notoungulata, Hegetotheriidae) de la Formación
Divisadero Largo de la provincia de Mendoza, Argentina.
Ameghiniana, 39:295-306.
FAUNA OF CHILE AND THE EARLY STAGES OF “MODERNIZATION” OF SOUTH AMERICA MAMMAL FAUNAS 209
Arq. Mus. Nac., Rio de Janeiro, v.66, n.1, p.191-211, jan./mar.2008
LÓPEZ, G. & BOND, M., 1995. Un nuevo Notopithecinae
(Notoungulata, Typotheria) del Terciario Inferior de la
Puna, Argentina. Studia Geológica Salmanticensia,
31:87-99.
LÓPEZ, G. & MANASSERO, M., 2006. Determinación
de la procedência estratigráfica de Ethegotherium carettei
Minoprio, 1947 (Notoungulata, Hegetotheriidae) a partir
de un análisis de petrografía sedimentaria.
Ameghiniana, 43:44-45R.
LÓPEZ, G.; BOND, M.; REGUERO, M.; GELFO, J. &
KRAMARZ, A., 2005. Los ungulados del Eoceno-
Oligoceno de la Gran Barranca, Chubut. In: CONGRESO
GEOLÓGICO ARGENTINO, 15., 2005, El Calafate.
Actas… El Calafate. CD-ROM, Artículo Nº 805, 5p.
MACFADDEN, B.J.; CAMPBELL, K.E., JR.; CIFELLI, R.L.;
SILES, O.; JOHNSON, N.M.; NAESER, C.W. & ZEITLER,
P.K., 1985. Magnetic polarity stratigraphy and mammalian
fauna of the Deseadan (Late Oligocene-Early Miocene) Salla
Beds of northern Bolivia. Journal of Geology, 93:223-250.
MARSHALL, L.G. & CIFELLI, R.L., 1989. Analysis of
changing diversity patters in Cenozoic land mammal age
faunas, South America. Palaeovertebrata, 19:169-210.
MARSHALL, L.G. & MUIZON, C.D., 1988. The dawn of
the Age of Mammals in South America. National
Geographic Research, 4:23-55.
MARSHALL, L.G.; HOFFSTETTER, R. & PASCUAL, R.,
1983. Mammals and stratigraphy: geochronology of the
mammal-bearing Tertiary of South America.
Palaeovertebrata, Mémoire Extraordinaire, 1983:1-93.
MARSHALL, L.G.; CIFELLI, R.L.; DRAKE, R.E. & CURTIS,
G.H., 1986. Vertebrate paleontology, geology, and
geochronology of the Tapera de López and Scarritt
Pocket, Chubut Province, Argentina. Journal of
Paleontology, 60:920-951.
MARSHALL, L.G.; WEBB, S.D.; SEPKOSKI, J.J., JR. &
RAUP, D.M., 1982. Mammalian evolution and the Great
American Interchange. Science, 215:1351-1357.
MCKENNA, M.C. & BELL, S.K., 1997. Classification of
mammals above the species level. New York: Columbia
University Press. 631p.
PASCUAL, R. & ORTIZ JAUREGUIZAR, E., 1990.
Evolving climates and mammal faunas in Cenozoic South
America. Journal of Human Evolution, 19:23-60.
PASCUAL, R.; VUCETICH, M.G.; SCILLATO YANÉ, G.J.
& BOND, M., 1985. Main pathways of mammal
diversification in South America. In: STEHLI, F.G. &
WEBB, S.D. (Eds.) The Great American Biotic
Interchange. New York: Plenum Press. p.219-247.
PATTERSON, B., 1934. Trachytherus, a typotherid from
the Deseado beds of Patagonia. Field Museum of Natural
History, 6:119-139.
PATTERSON, B. & PASCUAL, R., 1968. The fossil
mammal fauna of South America. Quarterly Review of
Biology, 43:409-451.
PAULA COUTO, C., 1983. Geochronology and
paleontology of the basin of Tremembé-Taubaté, State
of São Paulo. Iheringia, 8:5-31.
POWELL, J. & DERACO, M., 2003. Un nuevo leontinido
(Mammalia, Notoungulata) del miembro superior de la
Formación Lumbrera (Subgrupo Santa Bárbara) del
noroeste Argentino. Ameghiniana, 37: 68-69R.
PROTHERO, D.R. & BERGGREN, W.A., 1992. Eocene-
Oligocene Climatic and Biotic Evolution. Princeton:
Princeton University Press. 568p.
REGUERO, M.A., 1993. Los Typotheria y Hegetotheria
(Mammalia, Notoungulata) Eocenos de la localidad
Cañadón Blanco, Chubut. Ameghiniana, 30:336.
REGUERO, M.A. & CASTRO, P.V., 2004. Un nuevo
Trachytheriinae (Mammalia, †Notoungulata) del Deseadense
(Oligoceno tardío) de Patagonia, Argentina: implicancias en
la filogenia, biogeografía y bioestratigrafía de los
Mesotheriidae. Revista Geológica de Chile, 31:45-64.
REGUERO, M. & CERDEÑO, E., 2001. New
Hegetotheriidae (Notoungulata) from the Deseadan (Late
Oligocene) of Salla (Bolivia). Ameghiniana, 38:17R.
REGUERO, M. & CERDEÑO, E., 2005. New late
Oligocene Hegetotheriidae (Mammalia, Notoungulata)
from Salla, Bolivia. Journal of Vertebrate Paleontology,
25:674-684.
REGUERO, M. & ESCRIBANO, V., 1996. Trachytherus
spegazzinianus Ameghino, 1889 (Notoungulata:
Mesotheriidae) de la edad Deseadense (Oligoceno
superior - Mioceno inferior) de Argentina y Bolivia.
Naturalia Patagónica, Ciencias de la Tierra, 4:43-71.
REGUERO, M. & LÓPEZ, G., 1999. Un nuevo
Archaeohyracidae (Notoungulata, Hegetotheria) del
Paleógeno de Antofagasta de la Sierra, provincia de
Catamarca, Argentina. Ameghiniana, 36:107.
REGUERO, M.A.; UBILLA, M. & PEREA, D., 1995. A new
species of Archaeohyracidae (Mammalia: Notoungulata)
from Fray Bentos Formation (Deseadan) of Uruguay. In:
JORNADAS ARGENTINAS DE PALEONTOLOGÍA DE
VERTEBRADOS, 11., 1995, Tucumán. Resúmenes…
Tucumán: Asociación Paleontológica Argentina. p.16.
REGUERO, M.A.; UBILLA, M. & PEREA, D., 2003b. A
new species of Eopachyrucos (Mammalia, Notoungulata,
Interatheriidae) from the late Oligocene of Uruguay.
Journal of Vertebrate Paleontology, 23:445-457.
210 D.A.CROFT, J.J.FLYNN & A.R.WYSS
Arq. Mus. Nac., Rio de Janeiro, v.66, n.1, p.191-211, jan./mar.2008
REGUERO, M.A.; CROFT, D.A.; FLYNN, J.J. & WYSS,
A.R., 2003a. Small archaeohyracids from Chubut
Province, Argentina and central Chile: implications for
trans-Andean temporal correlation. Fieldiana, 48:1-17.
REGUERO, M.A.; CROFT, D.A.; LÓPEZ, G.J. & ALONSO,
R.N., in press. Eocene archaeohyracids (Mammalia:
Notoungulata: Hegetotheria) from the Puna, northwest
Argentina. Journal of South American Earth Sciences.
RIGGS, E.S. & PATTERSON, B., 1935. Description of
some notoungulates from the Casamayor (Notostylops)
beds of Patagonia. Proceedings of the American
Philosophical Society, 75:163-215.
RINGUELET, A.B.D., 1957. Estudio del género
Chasicotherium Cabrera y Kraglievich 1931 (Notoungulata-
Homalodotheriidae). Ameghiniana, 1:7-14.
ROTH, S., 1901. Notas sobre algunos nuevos mamíferos
fósiles. Revista del Museo de La Plata, 10:251-258.
ROTH, S., 1903. Noticias preliminares sobre nuevos
mamíferos fósiles del Cretáceo superior y Terciario
inferior de la Patagonia. Revista del Museo de La Plata,
11:133-158.
SHOCKEY, B.J., 1997a. Toxodontia of Salla, Bolivia
(late Oligocene): taxonomy, systematics, and
functional morphology. Dissertation (Ph.D.), University
of Florida. Unpublished.
SHOCKEY, B.J., 1997b. Two new notoungulates (Family
Notohippidae) from the Salla Beds of Bolivia (Deseadan:
late Oligocene): systematics and functional morphology.
Journal of Vertebrate Paleontology, 17:584-599.
SHOCKEY, B.J., 2005. New leontiniids (Class Mammalia,
Order Notoungulata, Family Leontiniidae) from the Salla
Beds of Bolivia (Deseadan, late Oligocene). Bulletin of
the Florida Museum of Natural History, 45:249-260.
SHOCKEY, B.J.; CROFT, D.A. & ANAYA, F., 2007.
Analysis of function in the absence of extant functional
analogs: a case study of mesotheriid notoungulates.
Paleobiology, 33:228-248.
SHOCKEY, B.J.; HITZ, R. & BOND, M., 2004. Paleogene
notoungulates from the Amazon Basin of Peru. Natural
History Museum of Los Angeles County, Science
Series, 40:61-69.
SHOCKEY, B.J.; SALAS, R.; QUISPE, R.; FLORES, A.;
SARGIS, E.J.; ACOSTA, J.; PINO, A.; JARICA, N.J. &
URBINA, M., 2006. Discovery of Deseadan fossils in the
upper Moquegua Formation (late Oligocene - ?early
Miocene) of southern Peru. Journal of Vertebrate
Paleontology, 26:205-208.
SIMPSON, G.G., 1932a. Skulls and brains of some
mammals from the Notostylops beds of Patagonia.
American Museum Novitates, 578:1-11.
SIMPSON, G.G., 1932b. New or little-known ungulates
from the Pyrotherium and Colpodon beds of Patagonia.
American Museum Novitates, 576:1-13.
SIMPSON, G.G., 1934. A new notoungulate from the
early Tertiary of Patagonia. American Museum
Novitates, 735:1-3.
SIMPSON, G.G., 1935a. Descriptions of the oldest known
South American mammals, from Rio Chico Formation.
American Museum Novitates, 793:1-25.
SIMPSON, G.G., 1935b. Occurrence and relationships
of the Rio Chico fauna of Patagonia. American Museum
Novitates, 818:1-21.
SIMPSON, G.G., 1945a. The principles of classification
and a classification of mammals. Bulletin of the
American Museum of Natural History, 85:1-350.
SIMPSON, G.G., 1945b. A Deseado hegetothere from
Patagonia. American Journal of Science, 243:550-564.
SIMPSON, G.G., 1948. The beginning of the age of
mammals in South America. Part I. Bulletin of the
American Museum of Natural History, 91:1-232.
SIMPSON, G.G., 1967. The beginning of the age of
mammals in South America. Part II. Bulletin of the
American Museum of Natural History, 137:1-260.
SIMPSON, G.G., 1980. Splendid Isolation, the Curious
History of South American Mammals. New Haven: Yale
University Press. 266p.
SIMPSON, G.G., 1984. Discoverers of the Lost World.
New Haven: Yale University Press. 222p.
SIMPSON, G.G. & MINOPRIO, J.L., 1949. A new
adiathine litoptern and associated mammals from a
Deseadan faunule in Mendoza, Argentina. American
Museum Novitates, 1434:1-27.
SIMPSON, G.G.; MINOPRIO, J.L. & PATTERSON, B.,
1962. The mammalian fauna of the Divisadero Largo
Formation, Mendoza, Argentina. Bulletin of the
Museum of Comparative Zoology, 127:239-293.
SOKAL, R.R. & ROHLF, F.J., 1995. Biometry. San
Francisco: W.H. Freeman & Company. 887p.
SORIA, M.F. & ALVARENGA, H.M.F., 1989. Nuevos
restos de mamíferos de la Cuenca de Taubaté, estado
de São Paulo, Brasil. Anais da Academia Brasileira de
Ciências, 61:157-175.
SYDOW, H., 1988. Postcranial skeleton of
Trachytherus (Mammalia, Notoungulata) with an
evaluation of dentition. Master’s thesis, University of
Florida. Unpublished.
FAUNA OF CHILE AND THE EARLY STAGES OF “MODERNIZATION” OF SOUTH AMERICA MAMMAL FAUNAS 211
Arq. Mus. Nac., Rio de Janeiro, v.66, n.1, p.191-211, jan./mar.2008
TOWNSEND, K.E., 2004. Stratigraphy, paleoecology, and
habitat change in the middle Eocene of North America.
Dissertation (Ph.D.), Washington University. Unpublished.
VILLARROEL, C. & COLWELL DANIS, J., 1997. A new
leontiniid notoungulate. In: KAY, R.F.; MADDEN, R.H.;
CIFELLI, R.L. & FLYNN, J.J. (Eds.) Vertebrate
Paleontology in the Neotropics: the Miocene Fauna
of La Venta, Colombia. Washington, D.C.: Smithsonian
Institution Press. p.355-381.
VUCETICH, M.G., 1980. Un nuevo Notostylopidae
(Mammalia: Notoungulata) proveniente de la Formación
Lumbrera (Grupo Salta) del noroeste Argentino.
Ameghiniana, 17:363-372.
VUCETICH, M.G. & RIBEIRO, A.M., 2003. A new and
primitive rodent from the Tremembé Formation (Late
Oligocene) of Brazil, with comments on the morphology
of the lower premolars of caviomorph rodents. Revista
Brasileira de Paleontologia, 5:73-82.
WEBB, S.D., 1976. Mammalian faunal dynamics of the
great American interchange. Paleobiology, 2:220-234.
WERTHEIM, J.A.; CROFT, D.A.; FLYNN, J.J. & WYSS,
A.R., 2005. New rodent faunas spanning several SALMAs
from the Laguna del Laja region, Andean Main Range,
central Chile. Journal of Vertebrate Paleontology,
25:129A.
WERTHEIM, J.A.; FLYNN, J.J.; GANS, P. & WYSS, A.R.,
2004. New chronologic information for the Laguna del
Laja mammal fauna(s): implications for the SALMA
sequence. Journal of Vertebrate Paleontology,
24:128A.
WOLFE, J.A., 1971. Tertiary climatic fluctuations and
methods of analysis of Tertiary floras. Palaeogeography,
Palaeoclimatology, Palaeoecology, 9:27-57.
WYSS, A.R.; CHARRIER, R. & FLYNN, J.J., 1996. Fossil
mammals as a tool in Andean stratigraphy: Dwindling
evidence of late Cretaceous volcanism in the South
central Main Range. Paleobios, 17:13-27.
WYSS, A.R.; FLYNN, J.J. & CROFT, D.A., 2005. New
notohippids (Notoungulata, Eutheria) from the central
Chilean Andes. Journal of Vertebrate Paleontology,
25:132A.
WYSS, A.R.; CHARRIER, R.; CROFT, D.A.; FLYNN, J.J.
& WERTHEIM, J.A., 2003. New middle Cenozoic
mammals from the Laguna del Laja region (Cura-Mallín
Formation, south central Chile). Journal of Vertebrate
Paleontology, 23:113A.
WYSS, A.R.; FLYNN, J.J.; NORELL, M.A.; SWISHER,
C.C., III; CHARRIER, R.; NOVACEK, M.J. & MCKENNA,
M.C., 1993. South America’s earliest rodent and
recognition of a new interval of mammalian evolution.
Nature, 365:434-437.
WYSS, A.R.; FLYNN, J.J.; NORELL, M.A.; SWISHER,
C.C., III; NOVACEK, M.J.; MCKENNA, M.C. &
CHARRIER, R., 1994. Paleogene mammals from the
Andes of central Chile: a preliminary taxonomic,
biostratigraphic, and geochronologic assessment.
American Museum Novitates, 3098:1-31.
WYSS, A.R.; NORELL, M.A.; FLYNN, J.J.; NOVACEK,
M.J.; CHARRIER, R.; MCKENNA, M.C.; SWISHER, C.C.;
FRASINETTI, D. & JIN, M., 1990. A new early Tertiary
mammal fauna from central Chile: implications for
Andean stratigraphy and tectonics. Journal of
Vertebrate Paleontology, 10:518-522.
... THE PRE-PLEISTOCENE FOSSIL RECORD OF SLOTHS (folivorans/ phyllophagans) in Chile is long but relatively sparse. The geologically oldest record is Pseudoglyptodon chilensis from the early Oligocene (Rupelian; Tinguirirican South American Land Mammal 'Age' or SALMA; ~32 Ma) Tinguiririca Fauna in the Abanico Formation at Termas del Flaco (McKenna et al., 2006), located in central Chile ~175 km southeast of Santiago (~35° S; see Wyss et al., 1993Wyss et al., , 1994Wyss et al., , 2018Flynn et al., 2003Flynn et al., , 2012Croft et al., 2008). This is among the earliest records of sloths in South America, exceeded only by slightly older (Priabonian; Mustersan SALMA; ~37 Ma) remains of an unidentified species of Pseudoglyptodon from AMEGHINIANA -2024 -Volume 61(3): 148-169 ARTICLES ...
... Five specimens with complete dentition and braincase, four of them with the mandibles, offer an exceptional possibility of performing an ontogenetic study focused on a leontiniid notoungulate recorded previously to the 'modernization' of the native ungulate faunas in South America (Croft et al. 2008). In this contribution, we present new material of Coquenia bondi, studying its craniodental features quali and quantitative variations to modelling the ontogeny of the species and confront our results with previous studies of cranial ontogeny of notoungulates. ...
... Nevertheless, Goin et al. (2010) noted marked changes in metatherian mammal faunas across this interval and referred to it as the Bisagra Patagónica (Patagonian Hinge). Early Oligocene mammal faunas that immediately post-date the Bisagra Patagónica are the geologically oldest in which hypsodont taxa predominate (Croft et al., 2008;Flynn et al., 2003), likely due to the presence of open areas in South America, which developed in Patagonia by the Late Eocene Kohn et al., 2015). Late Oligocene and Early Miocene South American faunas are well-represented and diverse and indicate that large-bodied representatives of several clades (including sparassodonts) disappeared during the Oligocene-Miocene transition (Scillato-Yané, 1977). ...
Chapter
Sparassodonts in South America and hyaenodonts in Africa present an interesting test case for comparing the evolutionary trajectories of ecologically similar clades on once isolated continents. Despite being distantly related within Mammalia (sparassodonts are metatherians and hyaenodonts are eutherians), they share many adaptations for a carnivorous diet, including an entire molar row modified into carnassials. Using data from the NOW database, we find that both groups became increasingly carnivorous during the Cenozoic, though only hyaenodonts showed a corresponding increase in body size. This difference may be due to different reproductive strategies in the two groups. Further comparisons between these groups and comparisons with modern carnivorans are necessary to determine the degree to which parallels and differences in the evolutionary trajectories of all three are related to the number of pairs of carnassialized teeth (i.e., several versus only one) and the adaptability of the distal tooth row.KeywordsBody MassCarnivoryEndemismIsland ContinentHyaenodontaPaleobiologyMetatheriaSparassodonta
Article
Full-text available
Dental ecometric traits in large herbivores have been used to reconstruct palaeoenvi- ronments, given the known relationships that these traits have to modern environments (such as the negative correlation between hypsodonty and precipitation). These tech- niques have largely focused on environments in North America and particularly both Eurasia and Africa, and consequently ecometric models have been trained on groups of herbivores that are most significant in those regions today (Artiodactyla, Perissodac- tyla, Primates and Proboscidea). The extent to which these relationships are persistent in communities with other dominant herbivores has never been tested. Because South America has been isolated for most of its history, fossil assemblages in the continent contain other clades, which likely have different trait–environment relationships due to their evolutionary history. Quantitative testing of these relationships and tailored regional models for South America, particularly those incorporating dietary infor- mation, will improve palaeoenvironmental reconstructions in the continent using mammal communities.
Article
Full-text available
Ever since the discovery of Macrauchenia patachonica by Charles Darwin in 1834, the affinities of litopterns—a group of extinct South American Native Ungulates (SANUs)—have been elusive. In particular, the interfamilial relationships and timing of the familial diversification within the order Litopterna have not been addressed with adequate taxon and character sampling, and modern phylogenetic methods. We address these issues using a new morphological matrix of 703 dental and mandibular characters, scored for the earliest litopterns alongside early SANUs of other orders (Astrapotheria, Notoungulata, Pyrotheria, and Xenungulata). We also included members of families that have been often included within Litopterna, such as Didolodontidae, Protolipternidae, Indaleciidae, and Notonychopidae, the last two sometimes grouped in the order Notopterna. We conducted maximum parsimony and undated and tip-dated Bayesian phylogenetic analyses. Our results indicate that (1) didolodontids, protolipternids, and kollpaniines should be considered early SANUs, but not particularly closely related to any order, (2) Indaleciidae and Notonychopidae usually form a monophyletic group (Notopterna), and (3) Litopterna is a monophyletic unit composed of four families [Adianthidae, Anisolambdidae (subfamilies Anisolambdinae and Sparnotheriodontinae), Macraucheniidae, Proterotheriidae], and tentatively the notoptern families Indaleciidae and Notonychopidae with a probable origin ~64.0 Mya in the Early Palaeocene.
Article
The late Eocene to earliest Miocene volcanic arc of the Southern Central Andes (33-40°S) and North Patagonian Andes (40-44°S) exhibits distinctive features that shed light on the dynamics of subduction-related volcanic activity in extensional tectonic settings. This period is particularly significant in the Andes, as it records the opening of forearc, intra-arc, and retroarc extensional basins, accompanied by high-volume volcanism, preceding the middle-late Miocene final major uplift phase of the Andes. This extensional event occurred in two phases, associated with changes in the geometry and dynamics of the subduction system: from oblique convergence at low rates during the late Eocene-early Oligocene to an orthogonal convergence at high rates during the late Oligocene-early Miocene. This study presents a compilation of field, petrographic, geochemical, and isotopic data from volcanic sequences in the North Patagonian Andes and the Southern Central Andes, aiming to analyze petrogenetic processes at different stages of arc evolution. During the late Eocene to early Oligocene, subduction-related volcanism occurred in a wide area from 100 to 300 km from the trench. In this period, magmatic arc rocks exhibit intermediate composition and a relatively homogeneous geochemical signature, transitional between tholeiitic and calc-alkaline series, with a marked subduction-related signature. These magmas originated from depleted mantle sources with high slab-derived fluid and sediment contributions and limited crustal interactions. In contrast, the late Oligocene to earliest Miocene volcanic activity, at the peak of the extensional regime, displays significant geochemical differences along the Andes. In the Southern Central Andes (33-40°S), volcanism displays compositions similar to those of the previous stage with varying influence from the subducting slab. In some sectors, magmas register the climax of the extensional conditions, whereas the youngest volcanic rocks towards the north (33-34°S) present evidence of the onset of contractional tectonics, demonstrated by the increased interaction of the magmas with a progressively thickened crust. In the North Patagonian Andes (40-44°S), subaerial and subaqueous arc-related lava flows are interbedded with marine deposits, indicating a rapid subsidence regime. These rocks exhibit geochemical features transitional from arc to E-MORB and even OIB compositions, which suggest a genesis primarily dominated by decompression melting of a heterogeneous mantle source. Above all, the contrasting nature of late Eocene-early Miocene arc products in the Southern Central and Patagonian Andes highlights that no single process can explain the changes in composition, distribution, and evolution of arc magmatism; rather, it is a combination of factors, including variations in subduction zone configuration and mantle dynamics and composition.
Book
This volume presents an array of different case studies which take as primary material data sourced from the NOW (‘New and Old Worlds’) database of fossil mammals. The NOW database was one of the very first large paleobiological databases, and since 1996 it has been expanded from including mainly Neogene European land mammals to cover the entire Cenozoic at a global scale. In the last two decades the number of works that are based in the use of huge databases to explore ecological and evolutionary questions has increased exponentially, and even though the importance of big data in paleobiological research has been outlined in selected chapters of general works, no volume has appeared before this one which solely focuses on the databases as a primary source in reconstructing the past. The purpose of this book is to provide an illustrative volume showing the importance of big data in paleobiological research, and presenting a broad array of unpublished examples and case studies. The book is mainly aimed to professional palaeobiologists working with Cenozoic land mammals, but the scope of the book is broad enough to fit the interest for evolutionary biologists, paleoclimatologists and paleoecologists. The volume is divided in four parts. The first part includes two chapters on the development of large paleobiological databases, providing a first-hand account on the logic and the functioning of these databases. This is a much-needed perspective which is ignored by most researchers and users of such databases and, even if centered in the NOW database, the lessons that can be learned from this part can be extended to other examples. After this introductory part, the body of the book follows and is divided into three parts: patterns in regional faunas; large scale patterns and processes; and ecological, biogeographical and evolutionary patterns of key taxa. Each chapter is written by well-known specialists in the field, with some participation of members of the NOW advisory board. The array of selected mammal taxa ranges from carnivores, equids, ruminants and rodents to the genus Homo. The topics studied also include the diversification and radiation of major clades, large-scale paleobiogeographical patterns, the evolution of ecomorphological patterns and paleobiological problems such as evolution of body size or species longevity. In most cases the results are discussed in relation to protracted environmental or paleogeographic changes.
Chapter
Recent studies have demonstrated dramatic changes in North American rodent and lagomorph faunas through the Cenozoic, with open-habitat specialists (characterized by increased tooth crown height and adaptations for burrowing, jumping, or running) becoming common as open and arid habitats spread. These studies have primarily focused on continental scale analyses, but comparisons of regional and local scale changes are key to understanding how individual faunas changed over time and the roles exerted by topography and local climatic conditions on these faunal changes. Here, we use a database of all fossil rodents and lagomorphs in North America modified from NOW, MIOMAP, and FAUNMAP to compare faunas through time across nine distinct regions. Our analyses reveal asynchronous changes across the continent, with specialized dietary and locomotor adaptations in rodents and lagomorphs occurring earlier in relatively cool, arid regions at higher latitudes. Findings suggest topographic complexity and volcanic activity potentially drove aspects of ecomorphological evolution in rodents and lagomorphs. The attributes of open and arid-adapted taxa likely facilitated their spread from tectonically and volcanically active regions across the continent, as environmental conditions changed through the Cenozoic.KeywordsClimate changeHypsodontyMammal FaunasNorth AmericaRodentiaLagomorpha
Article
Full-text available
Body mass (BM) is a fundamental variable for many paleobiological investigations that is challenging to accurately infer for species that lack living representatives and/or close morphological analogs. This study explores this issue using notoungulates, a diverse group of extinct South American herbivorous mammals with an extensive fossil record. We use a new dataset of 1,900+ extant mammal species (from ~80,000 specimens) to estimate notoungulate BM based on head-body length and a published dataset of 400+ species (~2,100 specimens) to estimate BM based on occipital condyle width. Condylobasal length, stylopod diameter and circumference, and neck length data are used to explore factors that can confound BM predictions. We estimate the following BM ranges for 10 osteologically well-characterized species and calculate similar ranges for 30 others known from less complete remains: Toxodontia: Thomashuxleya externa (80–120 kg), Homalodotherium cunninghami (250–350 kg), Scarrittia canquelensis (450–550 kg), Adinotherium ovinum (75–90 kg), Nesodon imbricatus (350–400 kg), and Toxodon platensis 1,000–1,200 kg); Typotheria: Interatherium robustum (1.9–2.0 kg), Miocochilius anomopodus (9–14 kg), Protypotherium australe (3.5–4.0 kg), and Pachyrukhos moyani (1.2–1.6 kg). We suggest that species such as these can be used as “calibration points” when inferring BM of species known from more limited remains. Discrepancies between our estimates and previously-published studies are primarily due to the distinctive craniodental morphology of notoungulates and the robust limb bones of toxodontians. There is significant, non-random error correlated with body habitus (i.e., being relatively robust or gracile) in many variables traditionally used to estimate BM, including femur circumference, and new methods are needed to compensate for this.
Article
Full-text available
A revised diagnosis of the Leontiniidae (Class Mammalia, Order Notoungulata) is provided and leontiniids of the Deseadan South American Land Mammal "age" (SALMA; late Oligocene) are summarized. Two new species of leontinids from the Deseadan Salla Beds of Bolivia are described and placed within the new genus, Anayatherium; the smaller A. ekecoa and a much larger A. fortis. A phylogenetic analysis suggests that these species are closely related to the derived Patagonian genera Ancylocoelus and Colpodon, with the loss of the canine serving as a putative synapomorphy uniting these taxa. Although leontiniids are the most frequently encountered taxa at many other Deseadan localities, they are exceedingly rare at Salla. This scarcity, the scarcity of other ungulates with low crowned cheek teeth and the heavy tooth wear of a relatively young individual of A. ekecoa suggest that ungulates with low crowned teeth were at a selective disadvantage at Salla.
Article
The diverse fauna from Salla, western Bolivia, represents a rare glimpse into the evolutionary history of Tertiary South American mammals outside of Patagonia (Argentina). The Hegetotheriidae (Notoungulata) from the Deseadan of Salla are composed of two taxa, a new genus and species and a species of Prohegetotherium. Sallatherium altiplanense gen. et sp. nov., differs from Prohegetotherium by its very long, thin nasals; more medially placed labial groove on upper cheek teeth; more reduced I2-I3-C and i3-c separated by diastemata; and much narrower symphysis. The smaller, more common hegetothere from Salla is identified as Prohegetotherium schiaffinoi; the abundant new material from Bolivia permits a better characterization of this otherwise poorly known species from Uruguay and Argentina (Corrientes and Entre Rïos provinces). The Divisaderan Ethegotherium carettei from Argentina is regarded as a junior synonym of P. schiaffinoi, extending the chronologic range of the genus into the early Oligocene. A revised diagnosis of the type species of Prohegetotherium, P. sculptum, is provided based on new material. This species is known exclusively from Argentina.