Marcelo F. Tejedor
Facultad de Ciencias
Naturales, Sede Esquel,
Universidad Nacional de la
Patagonia ‘‘San Juan
Primate canines from the early Miocene
Pinturas Formation, Southern Argentina
Previously undescribed canines from the Pinturas Formation
(Santacrucian, early Miocene) in Patagonia, Argentina, indicate the
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Pinturas Formation, in southern Argentina,
by the Museo Argentino de Ciencias
Naturales (MACN), Buenos Aires, and the
base of the crown is not wide relative to the
height. The holotypes of S. ameghinorumState University of New York at Stony
Brook, have recovered an important collec-
tion of fossil mammals, including new
species of platyrrhine primates. The named
species are Soriacebus ameghinorum, S.
adrianae, Carlocebus carmenensis and C.
intermedius (Fleagle et al., 1987; Fleagle,
1990). Soriacebus and Carlocebus differ in
many aspects of their morphology, but the
species included in each genus are distin-
guished mainly by size. Only a few isolated
specimens from Pinturas preserve the
canines in situ, such as the holotypes of S.
ameghinorum and S. adrianae, and a maxilla
of S. ameghinorum (MACN-SC 4; see
below). The upper canine of the maxilla SC
4 and other isolated uppers attributed to S.
and S. adrianae [mandibles MACN-SC 2
and MACN-SC 59, see Figure 2(a)] have
broken canine crowns, but they are large
and broad at the base and were certainly
high-crowned. Specimens of both species of
Carlocebus do not have associated and com-
plete canines, except for some roots pre-
served in partial mandibles, and so do not
provide adequate evidence to infer the most
likely morphology.
The Pinturas Formation (Bown &
Larriestra, 1990) is a continental pyroclastic
and epiclastic aeolian deposit found in the
northwest Santa Cruz Province, Argentina,
in the upper valley of the Rı´o Pinturas and
its tributaries. The age of these sedi-
ments has been debated, but recent
0047–2484/02/080127+15$35.00/0
2002 Elsevier Science Ltd. All rights reserved.Bosco’’, Sarmiento 849,
(9200) Esquel, Provincia del
Chubut, Argentina. E-mail:
mtejedor@unpata.edu.ar
Received 21 October 1999
Revision received
28 February 2002 and
accepted 8 April 2002
Keywords: Platyrrhine
evolution, Patagonia, early
Miocene, canines.
presence of new p
ized structure; th
projecting beyon
relatively rounde
possible to disting
One taxon is slig
logically distinct.
if so it would ex
lineage. A third
(?Soriacebus). Oth
but precise attrib
nature of these
phylogenetic que
of fossil primate
previously recogn
Journal of Human E
doi:10.1006/jhev.20
Available online at
Introduction
Several paleontological expeditions to themate taxa. These isolated teeth exhibit a general-
crowns are robust at the base, slightly or non-
the occlusal plane of the cheek teeth, with a
or slightly sharp entocristid in the lowers. It is
sh at least one, possibly two, new primate genera.
ly smaller than Soriacebus adrianae and morpho-
e other may be an early relative of Alouatta, and
nd the temporal and geographic range of this
xon is represented by an advanced pitheciin
isolated canines could be attributed to Carlocebus,
ion remains uncertain. Despite the fragmentary
ecimens, and some unresolved taxonomic and
ns, there is clear evidence for a greater diversity
in Patagonia during the early Miocene than
d.

2002 Elsevier Science Ltd. All rights reserved.
lution (2002) 43, 127–141
.0565
p://www.idealibrary.com on
ameghinorum [see Table 5 and Figure 2(f)]
have a long and projecting crown, reduced
or absent lingual cingulum, no distolingual
heel, a relatively deep mesial groove and the

Description and distribution of canines in the Pinturas Formation
MACN-SC 81 Upper right
MACN-SC 97 Lower left
Portezuelo Sumich Sur
ci
Table 1
128 . . studies confirm an early Miocene age
between approximately 17·5 and 16·5 Ma
(Santacrucian) based on 40Ar/39Ar dating
(Fleagle et al., 1995). The correlation of
Pinturas localities was described by Fleagle
(1990) (see also Bown & Larriestra, 1990;
Fleagle et al., 1995). Undescribed canines
from Pinturas (Table 1) indicate the pres-
ence of new primate taxa, possibly more
than the two previously known genera—
MACN-SC 115 Upper left
MACN-SC 232 Lower right
MACN-SC 234 Lower right
MACN-SC 243 Lower left
MACN-SC 293 Upper left
MACN-SC 300 Lower left
MACN-SC 322 Upper left
MACN-SC 328 Upper left
*MACN-SC: Museo Argentino de CienNumber* Description
MACN-SC 22 Lower right
MACN-SC 48 Upper left
MACN-SC 60 Upper right
MACN-SC 66 Lower left
MACN-SC 68 Lower right
MACN-SC 76 Lower leftSoriacebus and Carlocebus.buccal side from the cemento–enamel junc-
tion to the tip of the crown. This measure-
ment was not taken on those teeth in which
the apex of the cusp is worn sufficiently to
form an area of dentine exposure of more
than 1 mm in diameter. With this measure it
is possible to calculate the index of crown
height (ICH) as a ratio of height/area
(Table 1) to show that there are different
morphs within the sample. Measurements of
Loma de la Lluvia
Loma de las Ranas
Ea. El Carmen
as Naturales-Santa Cruz collection.Locality
Rı´o Pinturas, locality unknown
Rı´o Pinturas, locality unknown
Rı´o Pinturas, locality unknown
Portezuelo Sumich Norte
Portezuelo Sumich Norte
Portezuelo Sumich Norte
Portezuelo Sumich Norte
Cauce Seco
Loma de las Ranas
Loma de las Ranas
Rı´o Pinturas, locality unknown
Portezuelo Sumich Norteselected living platyrrhine species are pre-
To avoid taxonomic misunderstandings,
throughout this paper I consider Pithecia,
Chiropotes, Cacajao, Soriacebus, Callicebus,
Homunculus and Carlocebus as part of the
subfamily Pitheciinae (or pitheciines), while
Pithecia, Chiropotes, Cacajao and Soriacebus
are included into the tribe Pitheciini (or
pitheciins).
Description
The new material includes isolated upper
and lower canines, some well preserved,
housed in the Museo Argentino de
Ciencias Naturales (MACN), Buenos Aires.
Measurements of these specimens are given
in Table 2. Crown height is taken on the
sented in Tables 3 and 4, in order to evalu-
ate whether there are significant differences
between males and females for each species
in comparison with the fossil specimens.
Lower canines
Several lower canines are known from
Pinturas localities. MACN-SC 243
[Figure 1(c) and 3(b)], SC 22 [Figure 1(b)]
and SC 66 show many similarities in mor-
phology and size (Table 2), and SC 243 and
SC 66 came from the locality of Portezuelo
Sumich Norte. This is the type and only
locality of S. ameghinorum, although several
remains of C. carmenensis and the two speci-
mens of C. intermedius were also recovered
from this locality. Comparisons suggest that