Late Cretaceous vertebrates including mammals from Bolivia.

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LATE CRETACEOUS VERTEBRATES, INCLUDING MAMMALS,
FROM TIUPAMPA, SOUTHCENTRAL BOLIVIA
by
CsnrsrraN DE MUIZON *, MTRETLLE GAYET **, ALArN LAVENU **, LARRy G. MARSHALL ***,
BenNano 516[ xxxr. & CARLos VILLAROEL *r(r.,k,É
Ansrnacr
A taxonomically diverse fossil fauna with small and
medium size vertebrates was recovered from the Late
Cretaceous (Maestrichtian) age El Molino Formation
at Tiupampa, southcentral Bolivia. Among the
known taxa, many new to science, are selacians, acti-
nopterygians, lungfish, amphibians, lizards, snakes,
turtles, crocodiles, and several mammals. This fin-
ding provides a unique and previously unavailable
opportunity to understand debated aspects of the
phylogenetic and biogeographic histories of these
groups.
A taxonomically rich vertebrate fauna was recently
recovered from the El Molino Formation (Late Creta-
ceous) in southcentral Bolivia. The most significant
discovery was made at the locality of Tiupampa in the
Cordillera Oriental on the eastern slope of the Alti-
RÉsutvtÉ
Une faune fossile, taxonomiquement diversifiée, de
vertébrés de petites et moyennes dimensions, a été
découverte dans la Formation El Molino du Crétacé
supérieur (Maestrichtien) à Tiupampa, dans le
Centre-Sud de Bolivie. Parmi les taxons découverts,
dont beaucoup sont nouveaux pour la science, se
trouvent des sélaciens, actinoptérygiens, dipneustes,
amphibiens, lézards, serpents, tortues, crocodiles, et
différents mammifères. Cette découverte fournit un
moyen exceptionnel, le meilleur obtenu à ce jour sur
ce continent, de mieux comprendre les problèmes de
l'histoire phylogénique et biogéographique de ces
groupes.
plano about 95 km southeast of Cochabamba (fig.
1A). The fauna includes three species of marsupial
mammals (1), representing the first Late Cretaceous
mammal locality known for Bolivia and the second
for South America (2, 3).
KEY-WORDS : VERTEBRATES, LATE CRETACEOUS, BoLIVIA, PALEoBIoGEoGRAPHY, CoRRELATIoNS.
Mors-crÉs : vERTÉBRÉS, cRÉTACÉ supÉRrEUR, BoLIvrE, parÉosrocÉocRApHrE, coRRÉLATroNS.
* Institut de Paléontologie (LA 12, CNRS), 8 rue de Buffon, 75005 paris, France.
** Office de la Recherche Scientifique et Technique Outre Mer, Université de Pau et des Pays de l'Adour, Laboraioire de Géodynamique des
Bassins sédimentaires, 64000 Pau, France.
*** Depart. of Geosciences, The University of Arizona, Tucson, Arizona 85721, U.S.A.
**** Laboratoire de Paléontologie (LA 327, CNRS), U.S.T.L., Place Eugène Bataillon, 34060 Montpellier Cedex, France.
***** Apdo. Aéreo 56833 Bogotà D.E. Columbia.
Geobios, no 16, fasc. 6p. 7 47 -7 53, I tabl., 2 fig. Lyon, décembre 1983

The El Molino Formation is in the Puca Group, the
upper part of which includes (from oldest to youn-
gest) the Aroifilla (in part), Chaunaca, El Molino,
and Santa Lucia formations (4, 5). The Puca Group is
located in the Andean Basin, a large sedimentary
structure covering northwest Argentina, southwest
Bolivia, and southern Peru (6), which includes
marine, freshwater, and continental rocks of Late
Cretaceous and Early Tertiary age (7).
The lithologic units in the Andean basin have been
given different names in Argentina, Bolivia, and
Peru. Recent studies of rocks and faunas throughout
the basin demonstrate the time equivalence of many
of these units. Based on faunal content the El Molino
Formation of Bolivia is confidently correlated with
the Lecho and Yacoraite Formations of Argentina,
and the Vilquechico Formation of Peru (5).
Paleogeographic reconstructions of Late Creta-
ceous strata of the El Molino Formation in the
Andean Basin are given by Russo & Rodrigo (8),
Cherroni (5), Martinez (7), and Bonaparte & Powell
(9). The most common lithology in the center of the
basin is a calcareous sandstone with intercalations of
mudstones, the base of which is characterized by a
thick level of the stromatolite Pucalithus (10). On the
margin of the basin such as near Vila Vila (fig. lA),
the sediments are more detrital, often represented by
red beds which erode to form extensive badland expo-
sures.
The El Molino Formation was initially regarded as
Senonian in age (4). Knowledge of abundant fossil
remains collected from several localities (10, 11), sup-
plemented by new material collected by us and cowor-
kers, permits a secure Maestrichtian age assignment
for this lithologic unit.
Charophytes (Porochara sp., Platychara cf. per-
lata, Amblyochara peruviana) from near San Lucas
(85 km southeast of Potosi) and Maragua (70 km
north of Potosi) are interpreted as Campanian- Maes-
trichtian in age (12) and they are similar to those of
the Vilquechico Formation of Peru.
From near the base of the formation at Torotoro
(fig. 1A), Cappetta (13) describes a selacian fauna
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B
VILLA VISCARA
melers
200
C
TIUPAMPA
+ iurlle,crôcodrle + rool costs
ê turlles
+ ,ishes
iu rt le, crocod r lès ,100
+gostropods, selocion
+ rool cosls
S Conglomerote fj Lrmesiones f] Sondstones
fI Gostropod L meslone f] strotes IlIl Poleozoic
Fig. I - Map of Boüvia showing principal fossil vertebrates localities in El Molino Formation (A) ; and tentatively correlated sections of El
Molino Formation at Vila Viscarra (B) and Tiupampa (C).
Carte de la Bolivie sigrialant les principales localités fossilifères de la Formation El Molino (A) ; et coupes stratigraphiques corrélées
de la Formation El Molino à Vila Viscarra (B) et Tiupampa (c).
O TR NIDÀD
oLApaz BOLIVIA
o((ô
ao" 66o
.8
ô 3OOlm
-a
.-- ARGENT!NA

-749-
(including Pucapristis brunisi, Pucabatis hoffstetteri,
Ischyrhiza hartenbergeri, Dasyatis branisai, D. moli-
noensis, D. schaefferr) which indicates a Maestrich-
tian age. At the same locality, but from near the top
of the formation, are abundant trackways of dino-
saurs (14), representing at least five kinds of sauro-
pods and theropods (15).
Stratigraphic sections of the El Molino Formation
from Vila Viscarra (about 2 km south of Vila Vila)
and Tiupampa (about 6 km southeast of Vila Vila)
show the lithology of the rocks and the known fossil
levels (fig. 1B, C). A tentative correlation of these sec-
tions is based largely on the presence of a gasteropod
rich limestone believed to be the same in both ; it is
located 120 m above the base of the formation at Vila
Viscarra (fig. lB) and 90 m above the base of the for-
mation at Tiupampa (fig. lC). The rocks in both sec-
tions are primarily white to red sandstone with inter-
calations of clays and mudstone. The presence of
abundant root casts in some levels and of dark orga-
nic rich levels in others, indicates marshy to palustral
depositional environments. The abundance of chan-
nels and the frequent occurrence of marked but not
rapid lateral facies changes indicate general deposi-
tion in a low energy regime, possibly overbank to del-
taic in origin.
Neither charophytes, nor pollens were obtained
from the sampled levels. Multiple vertebrate- bearing
levels were prospected in both sections.
At Vila Viscarra (fig. 18) the lower fossil level loca-
ted about 100 m above the base of the formation and
characterized by Pucopnslrs ScnaBnrrn, 1963 (16),
yielded a selacian fauna identical to that described
from the base of the El Molino Formation at Toro-
toro (13, l7). Actinopterygian fish from this level
include : a pycnodont (Pycnodontidae, Pycnodonti-
fo rmes), Lepidot es (Lepido t idae, Semiono t ifu rmes),
gars (Lepisosteidae, Semionotifurmes), cf . Rhineaster
(Ariidae, Siluriformes), a new gemts (Ictaluridae,
Silurifurmes), and cf. Miletes (Serrasalmidae, Chara-
ciformes). The first four taxa are also recorded from
the El Molino Formation at Hotel Cordillera and
Agua Clara, both regarded as Maestrichtian (18). A
lungfish, an indeterminate pleurodire turtle (19) and
two indeterminate crocodiles (20) are also known
from this level.
From a level about 150 m above the base ofthe for-
mation in the Vila Viscarra section (fig. 1B) were col-
lected several specimens of the turtle ? Roxochelys
vilsvilensis (Pelomedusidae, Pleurodira) (21). Roxo-
chelys is known from the Bauru Formation in Brazil
(9) and the Vilquechico Formation in Peru (9), both
regarded as Late Cretaceous in age. One specimen of
a small crocodile from this level is referred to Cyno-
dontosuchus cf . rothi (Baurusuchidae, Sebecosuchia)
(22), a species found with dinosaurs in the Neuquen
Group of Argentina (9).
The vertebrate fauna from Tiupampa is exception-
naly rich in specimens and taxa. Selacians, collected
from a limestone level about 90 m above the base of
the formation (fig. lC), are represented by Dasyatis
schaefferi, a species also known from the lower levels
at Vila Viscarra and Torotoro (17).
T IIJPATPA
Iêpisostrldae : sp. indet.
Erciaàe oli»eirci
cC. Phatrooifus
cf, EotrËclon
cf . Rhiæastet
lctâl,uldae: nov. gen.
cf. Rhodaia
cf- l*iletee
ct. Hopliae
ct. Petcichthya
Lepidosiren cf . pamdon
Iêptodàctylidae : sp. indet.
Igunidàe : sp, indet.
Caïophye sp,
+
+
+ï
+
?
Boid.e:sp.lindeÈ.
Eoidae: sp.2 indet.
Eoldaersp.llndet.
? RoætBlya ct. ttilaülensie + + +
Podoaenic ? btteilienais +
sp. indet.
Dyrosauld.c ! sp. lndet,
Crccldyua r 3p. lndet, ?
Roberthof fete tterta mtionalge ograp hica
Hàrsuplalia: sp. lndeÈ. À
ttàrsr4rlalla: sp. lndet. B
Tabl. 1 - Fossil vertebrates of Tiupampa (mammal bearing level)
and their occurrence in: I - other localities of the El
Molino Formation, Bolivia ; 2 - the Vilquechico Forma-
tion at Laguna Umayo, Peru ; 3 - other Late Cretaceous
formations of South America.
Yertébrés fossiles de Tiupampa (niveau à mammifères)
et indicaiion de leur présence dans : I - d'autres gise-
ments de la Formation El Molino, Bolivie ; 2 - la For-
mation Vilquechico à Laguna Umayo, Perou ;3
-d'autres formations du Crétacé terminal d'Amérique
du Sud.
Except for a few indeterminate fragments of turtles
observed high in the section (fig. 1C), the remaining
vertebrates (table 1) were all collected from a level

-150-
between ll0 m and 140 m above the base of the for-
mation at Tiupampa (fig. lC). Actinopterygii are
represented by seven orders and at least ten families,
some recorded for the first time in South America
(fig. 2). These are : gars (Lepisosteidae, Semionoti-
formes), Enchodus oliveirai (Enchdontidoe, Salmoni-
formes), cf . Phoreodus (Osteoglossidae, Osteoglossi-
formes), cf . Eohiodon (Hiodontidae, Osteoglossifor-
mes), cf. Rhinesster (Ariidoe, Silurifurmes), a new
gents (Ictoluridoe, Siluriformes), cf . Rhodsio (Chara-
cidae, Characiformes), cf. Miletes (Serrasalmidae,
Characiformes), cf. Hoplias (Erythrynidae, Charsci-
formes), and cf. Percichthys (Percichthyidae, Perci-
formes).
A marine fish, Enchodus, is of particular impor-
tance for correlation. Based on the smoothness of the
teeth, it is apparently referrable to E- oliveiroi (23), a
species known only from rocks of Maestrichtian age
in Congo (24), Morocco (24), and Brazil (25).
Fig,2 - Previous and present chronostratigraphic ranges of
Actinopterygii recorded from the El Molino Formation,
Taxa from the Tiupampa locality are marked by a wavy
line.
Anciennes et présentes extensions chronostratigraphi-
ques des Actinoptérygiens découverts dans la Formation
El Molino. Un trait sinueux correspond aux taxons de la
localité de Tiupampa.
The other actinopterygians from Tiupampa were
not previously recorded from rocks of Late Creta-
ceous age, and two points were considered in assi-
gning them to the Maestrichtian. First, comparison
was made with the fish fauna from Hotel Cordillera,
confidently regarded as Maestrichtian (18) and with
that from Laguna Umayo, Vilquechico Formation,
Late Cretaceous of Peru. Second are paleobiogeogra-
phic considerations.
The oldest siluriforms (Ariidoe, Ictaluridae) were
previously known from the Late Paleocene of North
America (26). Their discovery in the El Molino For-
mation consequently extends their first known occur-
rence to the Maestrichtian. The Ariidae have a world-
wide marine distribution only along coasts and can
enter freshwater river systems. It is probable that their
early biogeographic history involved dispersal at a
time when the American landmasses were either in
contact with or were close to those of Africa and
Europe (27). Ariidae must thus have originated before
Aptian (- ll0 Ma) time to permit this dispersal. Cf.
Rhinesster appears to be present at the Hotel Cordil-
lera, Tiupampa, and Vila Viscarra (lower level) locali-
ties. The new genus of the freshwater family lctaluri-
dae from Tiupampa is also the same as the one from
Hotel Cordillera (28).
Two freshwater families of Characiforms have
range extensions. The oldest Characidae were pre-
viously known from the Middle Paleocene (29) and
the Serrssalmidae from the Miocene (30) of South
America. The discovery of Choracidae in the El
Molino Formation at Hotel Cordillera and Agua
Clara (18), and of Serrosslmidse in the lower level of
Vila Viscarra (28), extends their first known occur-
rence to the Maestrichtian. Characiforms are found
to-day only in South America and Africa, a distribu-
tion suggesting their presence in Gondwana before
Aptian time.
Osteo glossidae and Hiodontidoe, typically stenoha-
line famillies, occur to-day in South America, Africa,
and Australia, and as fossils (Phoreodus, Hiodon,
Eohiodon) in the Eocene of North America (26). This
distribution suggests a Gondwana origin for those
families. Accepting the Tiupampa Osteoglossidoe as
cf . Phsreodus and Hiodontidae as cf . Eohiodon,then
they may have been participants in the Late Creta-
ceous faunal interchange that occurred between
North and South America (31).
No true percoid has previously been reported from
a typical Cretaceous level. The oldest previously
known true percoid was Proserranus (Serranidoe)
from the Danian (Early Paleocene) of Sweden (32).
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A hemaxanal complex from Hotel Cordillera may
represent a beryciform or a perciform. This locality is
primarily freshwater, but some remains belong to
marine taxa (selacian, pycnodont) and we therefore
cannot dismiss this element as a possible marine bery-
ciform. However, it probably belongs to a freshwater
taxon, possibly a Percichthyidoe (Percifurmes), a
family which evolved from a generalized marine
group much like the Serranidae (29). Two vertebrae
of Percichthyidse have been recovered from Laguna
Umayo, Vilquechico Formation, Late Cretaceous of
Peru. The distribution of living Percichthyidae is dis-
junct, including southern South America, western
North America, southeast Australia, and northeast
Asia (33), and was surely more widespread in the past.
Erythrynidae (cf. Hoplias) are a typically South
American freshwater group. The oldest previously
known fossils were from the Miocene of Ecuador
(34). They are not known from any other locality of
the El Molino Formation, but are now listed from
Laguna Umayo, Vilquechico Formation, Peru.
The freshwater family Lepisosteidoe was not pre-
viously recorded in South America. This new record
from Tiupampa invalidates the view of Wiley (35)
who presents a biogeographic model predicting that
<<... only the vicariant sister group of gars may be
found among the fossil fauna of South America >>.
Thus, of the ten Actinopterygii families from Tiu-
pampa, seven (Enchiodontidae, Ariidae, Ictsluridae,
Serrasolmidae, Characidae, Erythrynidae, Per-
cichthyidae) have been recorded from the El Molino
and/or Vilquechico Formations. Two genera of
osteoglossiforms (cf. Phareodus, cf . Eohiodon) rnust
have been present in South America since Aptian time
and dispersed to North America before the end of the
Cretaceous. Based on the presence of Enchodus olî
veirai, a typical Maestrichtian marine species, and on
the fact that the other species do not conflict with
such an age assignment, a Maestrichtian age is sugges-
ted and favored by knowledge of the Actinopterygii
from Tiupampa (fig. 2).
Fossil lungfish are rarely recorded from South
America. Tooth plates of Lepidosiren have been
found in the Late Miocene of Columbia (36), in the
Eocene of Argentina (37) and in the Late Cretaceous
of Peru (38). No distinctive characters have been
published until now to warrant a separation of the
fossil tooth plates from those of Recent Lepidosiren
paradoxa (36, 37). Thus, even though the Lepidosiren
tooth plates of Tiupampa resemble closely those of
the Late Cretaceous of Peru, that alone cannot be
taken as an indubitable indication for the same age
(3e).
Amphibians are represented by frogs, apparently of
the family Leptodactylidae (40), iguanid lizards by an
indeterminate taxon, and snakes by one species of
Aniliidae (Coniophis sp.) and three species of Boidae
(40). Turtles are represented by ? Roxochelys cf . vila-
yilensis (19), and a << Podocnemis »» /s././, possibly
Podocnemis brssiliensis STAESCHE, 1937 (41) as
amended by Price, 1953 (42) from the Bauru Forma-
tion of Brazil (19). Crocodiles are represented by at
least three taxa: Sebecosuchis indet., Dyrosauridae
indet., and another group indet. (22). Whereas
various dinosaur trackways occur in El Molino limes-
tones at Torotoro, no sure dinosaur remains have yet
been recorded from the El Molino sandstones and
clays at Vila Viscarra and Tiupampa.
Mammals are represented by three species of Mar-
supialia all conservatively referred to the superfamily
Didelphoideo (l).
The Late Cretaceous (Maestrichtian) age vertebrate
fauna from the El Molino Formation in general and
from the Tiupampa locality in particular is diverse in
both number of specimens and taxa. Included from
Tiupampa are selacians, actinopterygians, lungfish,
amphibians, lizards, snakes, turtles, crocodiles, and
mammals. Many of the known taxa are new. Some
actinopterygians are recorded for the first time in
South America, and others are recorded for the first
time in rocks of Late Cretaceous age (being known
previously only from younger faunas). Mammals are
relatively abundant and the fauna is the first of Late
Cretaceous age known from Bolivia and only the
second for South America.
The Tiupampa locality is the first of Late Creta-
ceous age in South America to yield an abundance of
small and medium sized vertebrates (note infra.). It thus
provides a unique and previously unavailable oppor-
tunity for understanding aspects of the phylogenetic
and paleobiogeographic histories of these groups in
South America.
(note infra.) - Matrix collected from the principal vertebrate- bea-
ring levels at Vila Viscarra, Tiupampa, and Hotel Cordillera is pre-
sently being washed and sorted at the Laboratoire de Paléontolo-
gie, Montpellier for recovery of additional bones and teeth.

Funds for field work were provided by grant 2467-82 from
the National Geographic Society, Washington, D.C. The
field work was carried out under the auspices of I.B.B.A.
(Instituto Boliviano de Biologia de Altura) and the Mission
O.R.S.T.O.M. (Office de la Recherche Scientifique et Tech-
nique Outre-Mer). Field vehicles and other vital logistic
support were provided by Mission O.R.S.T.O.M. Support
for washing and sorting of matrix was provided by
E.P.H.E. (Ecole Pratique des Hautes Etudes), Montpellier.
\Me thank Robert Hoffstetter, Zofia Kielan-Jaworowska,
and Donald E. Russell for comments on the manuscript.
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Acknowledgements
RnrnnnNcns
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Manuscrit définitif reçu le 25.10.1983