Abstract and Figures

Human-megafauna interaction in the Americas has great scientific and ethical interest because of its implications on Pleistocene extinction. The Arroyo del Vizcaíno site near Sauce, Uruguay has already yielded over 1000 bones belonging to at least 27 individuals, mostly of the giant sloth Lestodon. The assemblage shows some taphonomic features suggestive of human presence, such as a mortality profile dominated by prime adults and little evidence of major fluvial transport. In addition, several bones present deep, asymmetrical, microstriated, sharp and shouldered marks similar to those produced by human stone tools. A few possible lithic elements have also been collected, one of which has the shape of a scraper and micropolish consistent with usage on dry hide. However, the radiocarbon age of the site is unexpectedly old (between 27 and 30 thousand years ago), and thus may be important for understanding the timing of the peopling of America.
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Research
Cite this article: Farin
˜a RA, Tambusso PS, Varela
L, Czerwonogora A, Di Giacomo M, Musso M
Bracco R, Gascue A. 2014 Arroyo del Vizcaı
´no,
Uruguay: a fossil-rich 30-ka-old megafaunal
locality with cut-marked bones. Proc. R. Soc. B
281: 20132211.
http://dx.doi.org/10.1098/rspb.2013.2211
Received: 23 August 2013
Accepted: 25 October 2013
Subject Areas:
palaeontology
Keywords:
megafauna, South America, Quaternary,
taphonomy, bonebed, peopling
Author for correspondence:
Richard A. Farin
˜a
e-mail: faria@fcien.edu.uy;
dogor@netgate.com.uy
Electronic supplementary material is available
at http://dx.doi.org/10.1098/rspb.2013.2211 or
via http://rspb.royalsocietypublishing.org.
Arroyo del Vizcaı
´no, Uruguay: a fossil-rich
30-ka-old megafaunal locality with
cut-marked bones
Richard A. Farin
˜a1, P. Sebastia
´n Tambusso1, Luciano Varela1,
Ada Czerwonogora1, Mariana Di Giacomo1, Marcos Musso2,
Roberto Bracco3and Andre
´s Gascue4
1
Seccio
´n Paleontologı
´a, Facultad de Ciencias, Universidad de la Repu
´blica, Igua
´4225, 11400 Montevideo, Uruguay
2
Seccio
´n Geote
´cnica, Facultad de Ingenierı
´a, Universidad de la Repu
´blica, Julio Herrera y Reissig 565,
11300 Montevideo, Uruguay
3
Laboratorio
14
C, Comisio
´n Nacional de Arqueologı
´a, Ca
´tedra de Radioquı
´mica, Facultad de Quı
´mica,
Universidad de la Repu
´blica, Gral. Flores 2124, 11200 Montevideo, Uruguay
4
Centro Universitario Regional Este, Universidad de la Repu
´blica, Burnett casi M. Chiossi (Campus Municipal ),
20000 Maldonado, Uruguay
Humanmegafauna interaction in the Americas has great scientific and ethi-
cal interest because of its implications on Pleistocene extinction. The Arroyo
del Vizcaı
´no site near Sauce, Uruguay has already yielded over 1000 bones
belonging to at least 27 individuals, mostly of the giant sloth Lestodon. The
assemblage shows some taphonomic features suggestive of human presence,
such as a mortality profile dominated by prime adults and little evidence of
major fluvial transport. In addition, several bones present deep, asymmetri-
cal, microstriated, sharp and shouldered marks similar to those produced by
human stone tools. A few possible lithic elements have also been collected,
one of which has the shape of a scraper and micropolish consistent with
usage on dry hide. However, the radiocarbon age of the site is unexpectedly
old (between 27 and 30 thousand years ago), and thus may be important for
understanding the timing of the peopling of America.
1. Introduction
(a) Background
The South American Pleistocene megafauna [1] includes spectacular, taxonomi-
cally unique assemblages of many giant-sized species whose extinction has been
attributed to human arrival in the past millennia of the Pleistocene [2]. Here, we
account for the megafaunal site of Arroyo del Vizcaı
´no, which had been prelimina-
rily dated to about 30 thousand years ago (hereafter, ka) [3]. Some fossils were
collected when the site was first discovered during a severe drought in January
1997. More rigorous excavations had to wait until permission was obtained from
the Comisio
´n del Patrimonio Cultural de la Nacio
´n and the weather conditions
became favourable. The results of two field seasons, undertaken in late March
2011 and in late January to early February 2012, are also reported here.
(b) Geological setting
The site (figure 1a) is formed by a streambed in a place where the stream becomes
deeper, forming a natural pond on a substrate of a Cretaceous silicified sandstone
(Mercedes Fm.) [4]. The sediments were exposed in an area of about 30 m
2
on the
basin delimited by the Mercedes Fm. (figure 1b). Three beds were identified. Bed 1
is a greenish muddy sand bed that is more than 0.60 m thick and lies unconform-
ably upon the Mercedes Fm. in the central, deeper part of the basin. Bed 2 is a richly
fossiliferous layer that is 0.60– 0.80 m thick, conformably overlying bed 1 and
fining upwards (see electronic supplementary material, figure S3) from a greenish
muddy sandy gravel (facies a) to a brownish muddy sand (facies b), with
&2013 The Author(s) Published by the Royal Society. All rights reserved.
polymictic (K-feldspar-quartz pegmatite, quartz, reworked
sandstones) clasts. Igneous clasts are angular to subangular
and reworked sandstone clasts are angular to rounded. Two
facies can be observed in bed 2, related with an upward shift
in coloration from green (facies a) to brown (facies b), which
may be due to slightly different sedimentary conditions or per-
haps differential postdepositional oxidation events. The
morphology of bed 2 is compatible with a fluvial system deposit
[5]. Finally, bed 3, which unconformably overlies bed 2, shows
variable thickness (0.20– 1 m) and is composed of reworked bed
2 sediments mixed with modern stream alluvium, mainly fine
sand and clayey silt.
Bed 2 is the main source of the remains studied here,
although some reworked elements are found in bed 3.
2. Material and methods
(a) Geology and age
Standard descriptive methods were followed for the geological
setting [6]. Seven additional samples [3], including purified and
non-purified bone collagen and wood [7], were radiocarbon
dated. See the electronic supplementary material for further details.
(b) Taphonomy
All the specimens were identified and counted. The biostrati-
nomical characterization of the vertebrate assemblage follows [8].
The number of specimens (NISP), minimum number of anatomical
units (MAU), minimum number of individuals (MNI) and mini-
mum number of elements (MNE) were calculated. Weathering
and evidence for transport of the bones were assessed through
macroscopical analyses.Unless otherwise stated, counts and percen-
tages refer to a total with glyptodont scutes excluded. Bones were
cleaned following the usual procedures [9]. Statistics follow
Sokal & Rohlf [10].
(c) Surface modifications of bones
Bones were examined under low magnification using a hand
lens to determine the presence of surface modifications and were
preliminarily classified to distinguish trampling from possible
anthropogenic marks [11]. Further analysis of selected marks was
carried out with light microscopy under magnifications of 20,
30and 45. Several pictures of the marks at different focal
depths were taken and a complete in-focus image was made. A
three-dimensional model of each mark accurately representing the
micromorphology of the modifications was constructed. At least
four perpendicular sections of the grooves were obtained for each
mark. The cross-sectional profiles were then digitized and measured
[12,13]. Five morphological attributes were measured [13], includ-
ing opening angle, angle of the tool impact index, shoulder height
index, depth of cut and floor radius. Other, larger bone modifi-
cations were macroscopically analysed through digital and plastic
models. Lithic material was analysed with the usual techniques
[14]. See the electronic supplementary material for further details.
3. Results and discussion
(a) Age
Based on nine samples of bone collagen and wood from bed
2b, the site age is between 27 +0.45 and 30.1 +0.6
14
Cka
1 km
Mercedes Fm
(a)
(b)
west dam
dam
east
bed 3, modern debris
bones in bed 2b
bones in bed 2a
01
m
bed 2b, fine facies
bed 2a, coarse facies
bed 1
Mercedes
formation Mercedes
formation
present flow
direction
libertad Fm dolores Fm
N
0.20 m
0.55 m
0.25 m
Figure 1. Arroyo del Vizcaı
´no site: (a) geographical location near Sauce, Departamento de Canelones, Uruguay (34837030S, 56820330W); (b) geological setting.
(Online version in colour.)
rspb.royalsocietypublishing.org Proc. R. Soc. B 281: 20132211
2
(see electronic supplementary material, table S1). Except for
the rib URU 0496, the other eight dates obtained are statisti-
cally the same ( p.0.05) and their pooled average is 29 +
0.106
14
C ka, between 32.298 and 31.219 cal ka (0.941).
(b) Assemblage characterization
The site is a bonebed with numerous, mostly megafaunal,
fossil remains. Only a small portion has yet been collected,
resulting in 1145 catalogue entries, with NISP ¼1095, or
779 excluding glyptodont scutes. Unless otherwise stated,
this number (779) will be used hereafter to make appropriate
comparisons and calculate percentages. The giant ground
sloth Lestodon armatus is the most abundant of the taxa rep-
resented (94% of the identifiable specimens, NISP ¼732,
MNI ¼17). A small number of elements of two other extinct
giant sloths (Glossotherium robustum and Mylodon darwinii),
three glyptodonts (Glyptodon cf. clavipes,Panochthus tubercula-
tus and Doedicurus clavicaudatus),one notoungulate (Toxodon
platensis), one fossil horse (Hippidion principale), one probosci-
dean (the gomphothere Stegomastodon sp.), one adult deer
(Cervidae indet.) and one sabretoothed felid (Smilodon
populator) were also collected.
Only a small number of bones have juvenile features: two
differently sized right femora, one left femur, a fragmentary
hyoid, two mandibular fragments, a rib, a sacrum, two ver-
tebrae, two tibiae, two caniniforms assigned to L. armatus,
one femur of a glyptodont, an incompletely worn deciduous
tooth of the gomphothere and the four horse bones, which
amounts to 20 identified specimens (2.6%) belonging to at
least five (mostly subadult) juvenile individuals. Owing to
the presence of osteoarthritis, 58 bones (7.4%) have been
identified as belonging to at least two old individuals. The
remaining 90% of the elements belong to adult, prime
individuals, yielding a prime-dominated mortality profile.
This profile is unlike those found in either attritionally, cata-
strophically or accidentally accumulated assemblages [15]. By
contrast, the age profile is similar to that seen in kill sites, in
which a selection of the strongest individuals by human hun-
ters with appropriate technology (long-distance weaponry)
and cooperative ambush strategies is implied.
Among the identified specimens, limb bones and girdles
(35.7%) predominate, followed by vertebrae (33.9%), rib por-
tions (15.7%), cranial fragments (9.2%), and bones of manus
and pes (5.3%). The proportions found resemble those of
the surface assemblage in Amboseli [16], African hominid
sites [17], carnivore dens [18] and San huntergatherer
camps [17] (figure 3a). The representation of all anatomical
regions despite their hydraulic transportability potential
[19] suggests the accumulation being mostly autochthonous,
with little evidence for major hydraulic transport, although
slight outgoing hydraulic transport might have removed
some of the lighter elements. Limb and elongated bones are
randomly oriented (figure 2), compatible with no major
sorting of the bones owing to fluvial transport [20] and
suggesting biogenic agency [8]. This, in turn, is congruent
with the sedimentological evidence of low current speed.
The teeth : vertebrae ratio of the sloth elements (as corrected
for making allowance of the appropriate numbers in the indi-
viduals of the clade, 18 and 34, respectively) is 0.76. This
resembles a trampled surface accumulation and is unlike a
sorting by transport, in which heavier, durable elements are
over-represented [16]. However, one-fifth of the bones show
some signs of transport and must have had a different tapho-
nomic history. In addition, between one-fifth and one-quarter
of the bones collected exhibit several features indicative of
transport, and are slightly more weathered [21] and trampled
than the majority of the recovered sample (see electronic
present flow
direction
(a) (c)
(b)
N
N
1 m
bones lacking a long axis
long bones
180°
elongated bones
180°
270° 90°
(104,1)
(99,4)
270° 90°
long + elongated bones
180°
270° 90°
(37,7)
long and elongated bones
lithic element
Figure 2. Panoramic view and orientation of the bones: (a) the bonebed showing the 1 m grid used to reference collected elements: (b) schematic of the bones to
show their orientation; (c) rose diagrams showing orientation of the bones. (Online version in colour.)
rspb.royalsocietypublishing.org Proc. R. Soc. B 281: 20132211
3
supplementary material, figure S6). Those specimens show
an orangish colour when wet and tend to come from the
lower part of bed 2 (facies a). The representation of the ana-
tomical units (%MAU) of L. armatus (figure 3b) resembles
those in kill sites associated with gourmet consumption [23].
In summary, fluvial agency can be ruled out as the main
source of the accumulation. This conclusion is also supported
by the general state of preservation of the bones, which mostly
display little abrasion and only a slight polish. However, the
existence of more than one population of bones cannot be dis-
carded or corroborated with the data currently available and
will require finer stratigraphic control in future excavations. In
any case, physical preservation is rather homogeneous in the
vast majority of the elements, indicating fast burial, perhaps as
a single event [24], which is congruent with the obtained dates.
Because major long-distance fluvial transport can be
excluded as the main origin of the accumulation, the fossil
association must have involved external factors. Among
such processes, natural trap or other catastrophic sources
can also be excluded [25], as they do not show the inverted
U-shaped age distribution found here (figure 3c).
(c) Surface modification of bones
No carnivore tooth marks were identified. Nearly 59% of the
bones collected show modifications with features identifiable
as trampling marks [26], with over one-third of the bones
exhibiting trampling abrasion on more than 25% of their sur-
face area (see electronic supplementary material, figure S7).
Furthermore, 40 elements (nearly 5% of the identified speci-
mens, a percentage similar to the proportion in human sites
[23]) show marks that have macroscopical features consistent
with human agency (figure 4; electronic supplementary
material, figures S8– S13). Ten of the bones that showed
little or no trampling abrasion in the studied area of the
anthropogenic-style marks were examined under greater
magnifications. A total of 15 marks were analysed from the
selected bones. Congruent with previous preliminary find-
ings [27], most of these marks show microscopical features
described in cuts made by human stone tools, such as
shoulder effects, Herzian cones and even microstriations
[12] (figure 4a–e; electronic supplementary material, table
S6), the latter being very rarely preserved in prehistoric
material [11,26]. The mean value of the opening angle was
112.5 +12.18. For the angle of tool impact (ATI) index, the
mean value was 0.089 +0.058, indicating that the object
that made the mark was on average oriented at a consistent
angle relative to the bone surface and not perpendicular to it.
The shoulders are 42 mm high on average (higher than in
many experimental marks [12]), with mean shoulder height
(SH) index value of 0.256 +0.251, similar to the published
values for a tool held at 458in regard to the bone surface [12].
The mean value for the depth of cut was 0.191+0.070 mm.
The floor radius shows a mean value of 0.161+0.073 mm
(figure 4a–d). These features and values resemble those found
in fossil bones cut with flint tools [13,28,29], including in
xenarthrans [30].
Most marks are observed in the anatomical regions that
would be expected to have been produced by humans, for
instance in the proximal portions of three ribs, trochlear
notch of an ulna, hyoid, lingual side of the lower jaw, etc.
[11,31]. Remarkably, at least one of the bones has marks
located in a very concave surface, the groove on the distal
epiphysis of a tibia (where the tendon of the flexor hallucis
longus muscle runs), which renders it nearly impossible
to have been caused by trampling [26]. Indentations are
discussed in the electronic supplementary material.
All individuals with body masses not much above one
tonne ( juvenile L. armatus, other ground sloths, adult and juven-
ile glyptodont, toxodont, juvenile gomphothere, juvenile horse,
deer, sabretooth) are represented by few bones (61, or 8%),
whereas the four-tonne adult individuals of L. armatus consti-
tute over 92% (718 specimens) of the identified specimens.
San hunter–gatherers have been reported [17] to schlep entire
carcasses with masses in excess of several hundred kilograms
to more permanent camps, whereas the largest individuals are
processed in situ. A similar pattern has been observed in archae-
ological kill sites [23]. Stalking by human hunters is performed
archaeological cave sites Amboseli
(buried)
50
(a)
(b)
(c)
40
30
FxJj50KB
Zinjanthropus
Zinjanthropus
Olduvai’s bed 1 frida
Leakey Korongo (FLK)
site
FxJj50KB
FxJj50 Koobi Fora Site
Olduvai 6:
FLKN level 6
Amboseli (exposed)
Amboseli:
Amboseli: National
Park
San:
San hunter–gatherers
camp
AdV:
Arroyo del Vizcaíno
Arro
y
o del Vizcaíno
brown and spotted hyaenas:
hyaena dens, Namib desert, Namibia
AdVbrown and
spotted hyaenas
San
modern human sites
modern ecosystems
carnivore dens
hominid sites
0
10
20
30
40
40
30
20
10
0
010 20 30 40 50 60 70 80 90 100
0–15 15–30 30–50
old
old-dominated
prime-
dominated
adult
juvenile
juvenile-
dominated
U-shaped
living
structure
bonesindividuals
boundary between
pattern types
01.0
0.9
0.8
0.7
0.6
0.5
0.5
0.4
0.4
0.3
0.3
0.2
0.1
0.2 0
0.10
0.1
0.2
0.3
0.4
0.5
0.6
0.6
0.7
0.7
0.8
0.8
0.9
0.9
1.0
1.0
50–90 90–100
vertebrae + ribs
50 50
60
70
80
90
100
100
limbs + girdles
90
80
70
phalanges
60
Olduvai 6
Figure 3. Frequency of the bones collected in Arroyo del Vizcaı
´no: (a)proportion
of anatomical regions found in biogenic sites with detail of the ternary diagram
near the position of the Arroyo del Vizcaı
´no (AdV) site recalculated and redrawn
after [22]; (b) percentage of minimum anatomical units of ground sloth bones;
(c) proportion of bones and individuals in the mortality profile.
rspb.royalsocietypublishing.org Proc. R. Soc. B 281: 20132211
4
in places in which the animalstransit frequently [15], such as on
the way to a body of water, which might help explain the
observed extent of the trampling.
(d) Lithic material
Although during the fieldwork no systematic effort was made
to collect lithic material and only a part of this site has been
exhaustively explored, a few lithic elements were found to
have seemingly anthropogenic features, although such elements
are scarce, as is usual in South American Pleistocene archaeolo-
gical sites [31]. These include flakes made of silicified sandstone
(see the electronic supplementary material), but their grain size
prevented further microscopical analysis. However, a small
piece of translucid silcrete has features compatible with a scra-
per (figure 4f,g) [32]. This piece was found in bed 2 in very
close association with several bones (figure 2b). It is a pseudo-
pyramidal nucleus with dimensions 29.6 14.5 15.5 mm.
Both proximal and distal borders are short and convex. They
are unifacially retouched and asymmetrically bevelled at inter-
mediate angles (708in the proximal border and 608in the
distal one). The proximal border presents marginal semicircular
retouching, and the distal border shows deep retouching of
irregularly parallel morphology. Using a scanning electron
microscope (SEM) at 700– 4300, an area was identified (aster-
isk in figure 4f) extending along a large portion of the distal edge
of the largest face that reflectsthe incidental electrons differently
from the central parts of that face. That area is rather dull and
coarse, with circular microdepressions that are darker than the
rest of the surface (see the electronic supplementary material,
figure S15), covering the high zones as well as the low ones,
and is accompanied by noteworthy edge rounding. These fea-
tures are consistent with those observed in a second-stage
micropolish, as produced by working on dry hide [33]. Micro-
polish is the only feature observable with optical microscopy
that is produced by the use of a tool and not by natural or acci-
dental causes, and thus it is a diagnostic indicator of human
agency even in the absence of any other kind of evidence [33].
Both retouched edges show a nearly continuous pattern of
microflaking of different size and morphology.
4. Final remarks
The taphonomy of the site, intrinsically important as a large
bonebed, is suggestive as having accumulated as the result of
biogenic (particularly human) agency. The presence of sur-
face modifications on the bones and the possible scraper are
consistent with this interpretation. However, besides some
rather controversial claims in both South [34 36] and North
[3741] America, current evidence for humans arriving in
the New World (excluding Beringia) before the Last Glacial
Maximum (as indicated by the dates at Arroyo del Vizcaı
´no)
is equivocal. Thus, the age of the site and the scarcity of
formal tools urge caution in interpretation. In any case, we
argue that the Arroyo del Vizcaı
´no site deserves to be
included in the agenda of early American peopling, either
as a not foreseeable discovery [37] or as an example of natural
processes mimicking human presence. As such, further
detailed study of the site is warranted to resolve these issues.
(a)
(d)
(i)
(ii)
(iii)
(b)5cm 2cm
1cm
1mm
5cm
*
(c)
(e)
(f) (g)
Figure 4. Bone surface modifications: (a) rib CAV 451; (b) detail of the proximal region; (c) detail of the cut marks: (d) three-dimensional reconstruction of the
boxed mark indicated in (c), indicating where sections (i), (ii) and (iii) were taken (section profiles show the two slopes and unaffected bone surface); (e) portion of
that cut mark displaying microstriations (arrow) preserved at the base of the groove (right), and parallel set of microstriations (arrow) preserved on a cut mark in CAV
453 showing a V-shaped section (left); (f) lithic element with features characteristic of a scraper, showing an area (*) that differentially reflects the incidental light;
(g) SEM photography showing micropolish in area *.
rspb.royalsocietypublishing.org Proc. R. Soc. B 281: 20132211
5
Acknowledgements. We are indebted to the following people and insti-
tutions for their help: Eileen Armstrong, Alfonso Arribas, Anna
K. Behrensmeyer, Martı
´n Batalle
´s, Silvia Bello, Batallo
´n 14, Cristina
Bertoni, Karen Borrazzo, Luis Borrero, Juan Cabrera, Reynaldo
Castilla, Gabriela Costoya, Comisio
´n Sectorial de Investigacio
´n
Cientı
´fica (CSIC) of the Universidad de la Repu
´blica, Eva Farin
˜a,
Gonza
´lez family, Signe Haakonsson, IMFIA, Intendencia de Cane-
lones, Emily Lindsey, Dimila Mothe
´, Gustavo Politis, Ximena
Martı
´nez Blanco, Rubens Ottonello and Municipio de Sauce,
Elena Pareja, Santiago Patin
˜o, William Rey, Jorge and Elena Rizzo,
Valeria Rodrı
´guez, Raymond R. Rogers, Ana Elisa Ro
¨hrdanz,
Andrea Sa
´nchez, Montevideo, Uruguay: Valetto family, Jorge
Wagensberg, Marcelo Arı
´stides Za
´rate and two anonymous
reviewers. R.A.F. wishes to acknowledge the indirect encouragement
by Beatriz Aguirre-Urreta, Ana Ba
´ez, Ismar Carvalho and Rodolfo
Mancen
˜ido, who regarded this project as too ‘ambitious’.
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rspb.royalsocietypublishing.org Proc. R. Soc. B 281: 20132211
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... Located in southern Uruguay (Fariña et al. 2014a), the Arroyo del Vizcaíno site (hereafter AdV) shows an impressive amount of Pleistocene megafaunal remains (Fariña et al. 2013), of which over 2,000 specimens have been collected. Excluding the many glyptodont osteoderms, 96% of the skeletal remains belong to the ground sloth Lestodon armatus. ...
... About 40 of 1,100 analyzed bones show bone surface modifications (BSM) with macroscopic features like those of cut-marks made by chipped stone tools. In Fariña et al. (2014a), 15 of these BSM (on 11 bones mainly of Lestodon but also of a glyptodont) were studied by taking 40x photographs at several depths and building up 3D models of the marks. The results showed compelling microscopic evidence of human agency, as will be discussed below (also see Fariña 2015 andDomínguez-Rodrigo et al. 2021). ...
... And, according to some exploratory digs in the neighboring area, fossils are even found below the surrounding banks of younger Quaternary deposits. This renders the AdV site possibly the most impressive mammalian paleontological site in Uruguay and because of its well-established chronology of more than 30 ky BP (Fariña et al. 2014a), the oldest site to provide evidence for a human presence in Uruguay (against the claims of Suárez 2015 to be discussed below) and among the oldest in the Americas. ...
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Here, we will address further criticisms in terms of the weakness and the strength of our proposal that the AdV is more than a particularly rich paleontological site, and our consequent intent to take it from a possible archaeological site to a probable one. In doing this, we are attempting to make progress in the central debate about the AdV and the more general subject of the peopling of the Americas. This matter is of major academic importance but also has ethical implications due to the proposed role of humans in the demise of the Pleistocene megafauna (see Sandom et al. 2014 for a thorough discussion).
... This early occupation of the continent can be even older, as suggested by a Bayesian age modelling of the oldest archaeological record and genetic evidence [14,15]. Adding to this, compelling evidence of a pre-LGM human presence in America could potentially be found at Arroyo del Vizcaíno [16][17][18][19] (hereafter, AdV) in southern Uruguay (34°37'2.92 00 S, 56°2'32.54 ...
... 00 W) (figure 1). This site, located at the bottom of a stream, has yielded a collection of over 2000 remains of South American Pleistocene megafauna (mostly belonging to the giant sloth Lestodon armatus), while many thousands are estimated yet to be extracted [16]. The fossils are densely packed in an approximately 70 cm thick level that fines upwards from a muddy sandy gravel (bed 2a) to a muddy sand (bed 2b) [9] (figure 1; electronic supplementary material). ...
... The fossils are densely packed in an approximately 70 cm thick level that fines upwards from a muddy sandy gravel (bed 2a) to a muddy sand (bed 2b) [9] (figure 1; electronic supplementary material). A total of 12 radiocarbon dates, which cluster at around 30 14 C kyr BP [16,17] (over 33 cal kyr BP), have been obtained from purified and non-purified collagen as well as from wood in different laboratories and at different times. The potential existence of cut-marks on the AdV bones advocates an earlier human presence in America, just before the LGM [18]. ...
Article
The earliest widely accepted presence of humans in America dates to approximately 17.5 cal kyr BP, at the end of the Last Glacial Maximum (LGM). Among other evidence, this presence is attested by stone tools and associated cut-marks and other bone surface modifications (BSM), interpreted as the result of the consumption of animals by humans. Claims of an older human presence in the continent have been made based on the proposed anthropogenic modification of faunal remains; however, these have been controversial due to the highly subjective nature of the interpretations. Here, we employ advanced deep learning algorithms to objectively increase the accuracy of BSM identification on bones. With several models that exhibit BSM classification accuracies greater than 94%, we use ensemble learning techniques to robustly classify a selected sample of BSM from the approximately 30 kyr BP site of Arroyo del Vizcaíno, Uruguay. Our results confidently show the presence of cut-marks imparted by stone tools on bones at the site. This result supports an earlier presence of humans in the American continent, expanding additional genetic and archaeological evidence of a human LGM and pre-LGM presence in the continent.
... Notwithstanding ample evidence of coexistence between the so-called megafauna and humans in several areas of South America since ca. 12 ka (see, among others Correal Urrego, 1981;Cione et al., 2003Cione et al., , 2009Borrero, 2009;Barnosky & Lindsey, 2010;Fariña et al., 2014;Pires et al., of Argentina (Politis & Gutiérrez, 1998). Apart from the Pampas, evidence is limited to the existence of a few glyptodont osteoderms at Late Pleistocene archaeological sites, making it difficult to determine the nature of interaction between humans and these megafaunal forms. ...
... Among the recovered remains, some of which were burned, one bone piece showed parallel-pattern traces of human cutting (see Oliver & Alexander, 2003, fig. 17;Aguilera, 2006, p. 28;Fariña et al., 2014). A fragment of the El Jobo type point and other stone elements such as scraper, a possible knife, and a hammerstones were found also in situ in the same archaeological strata (Rouse & Cruxent, 1963). ...
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The Muaco and Taima-Taima sites, in Falcón State of northwestern Venezuela, are among the earliest sites of human occupation in South America containing artifacts associated with preserved megafaunal remains and dating between 19,810 and 15,780 calybp. Here we report novel visual and CT scanning analysis of six glyptodont skulls of Glyptotherium cf. cylindricum from these sites, of which four exhibit distinct and similar patterns of breakages in the fronto-parietal region that suggest intentional blows by direct percussion by humans, with fractures not being diagenetic but instead antemortem or transmortem. This hypothesized and unreported hunting technique focused in an area of the skull where the cephalic shield becomes thin, thus increasing the effectiveness of the blow. From Taima-Taima other glyptodont remains included an inverted carapace, also previously reported as probable evidence of human–glyptodont interaction during the latest Pleistocene. We estimated that roughly 150-170 Kg of potentially accessible muscles and fat of an adult Glyptotherium cylindricum could be used as food sources.
... At Toca do Serrote das Moendas, Brazil, faunal remains associated with human bones were dated to between ∼29,000 and ∼24,000 cal BP (Kinoshita et al., 2014). And at Arroyo del Vizcaíno, Uruguay, a fossil-rich 30,000 years old megafaunal locality with cut-marked bones (Fariña et al., 2014) adds to a growing record of probable human occupation sites in the Americas that predate arrival of the Native American clade by millennia. ...
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Calibrating human population dispersals across Earth’s surface is fundamental to assessing rates and timing of anthropogenic impacts and distinguishing ecological phenomena influenced by humans from those that were not. Here, we describe the Hartley mammoth locality, which dates to 38,900–36,250 cal BP by AMS 14C analysis of hydroxyproline from bone collagen. We accept the standard view that elaborate stone technology of the Eurasian Upper Paleolithic was introduced into the Americas by arrival of the Native American clade ∼16,000 cal BP. It follows that if older cultural sites exist in the Americas, they might only be diagnosed using nuanced taphonomic approaches. We employed computed tomography (CT and μCT) and other state-of-the-art methods that had not previously been applied to investigating ancient American sites. This revealed multiple lines of taphonomic evidence suggesting that two mammoths were butchered using expedient lithic and bone technology, along with evidence diagnostic of controlled (domestic) fire. That this may be an ancient cultural site is corroborated by independent genetic evidence of two founding populations for humans in the Americas, which has already raised the possibility of a dispersal into the Americas by people of East Asian ancestry that preceded the Native American clade by millennia. The Hartley mammoth locality thus provides a new deep point of chronologic reference for occupation of the Americas and the attainment by humans of a near-global distribution.
... En Uruguay, Gómez Coutouly (2021) fait référence à Arroyo del Vizcaíno, non seulement sans citer la source principale (Fariña et al., 2014a) mais aussi sans citer la réponse de ces mêmes auteurs (Fariña et al., 2014b) à l'article de Suárez et al. (2014). Négligence que Borrero (2016) commet également. ...
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In this article, we outline a general reflection on the early peopling of the Americas, based on the main characteristics of this topic within the praxis of Americanist prehistory. We illustrate this reflection through a response to the critical review published in the second issue of volume 118 of the Bulletin de la Société préhistorique française.
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Neste capítulo, você vai entender um pouco melhor uma das primeiras e mais importantes consequências negativas da presença humana na natureza: a extinção dos grandes carnívoros e herbívoros do Cenozoico, conhecidos como megafauna, que trouxe mudanças drásticas para os ecossistemas do globo. Estudos sugerem que a extinção da megafauna interrompeu ciclos biogeoquímicos importantes para a ciclagem de nutrientes, alterou a cobertura vegetal em várias regiões e levou à coextinção de inúmeros organismos que dependiam direta e indiretamente desses grandes vertebrados.
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The extinct ‘Gomphotheriidae’ is the only proboscidean family that colonised South America. The phylogenetic position of the endemic taxa has been through several revisions using morphological comparisons. Morphological studies are enhanced by palaeogenetic analyses, a powerful tool to resolve phylogenetic relationships; however, aDNA preservation decreases in warmer regions. Despite the poor preservation conditions for aDNA in humid, sub-tropical climates, we recovered ∼3000 bp of mtDNA ofNotiomastodon platensis from the Arroyo del Vizcaíno site, Uruguay. Our calibrated phylogeny places Notiomastodon as a sister taxon to Elephantidae, with a divergence time of ∼13.5 Ma. Additionally, a total evidence analysis combining morphological and palaeogenetic data shows that the three most diverse clades within Proboscideadiverged during the early Miocene, coinciding with the formation of a land passage between Africa and Eurasia. Our results are a further step towards aDNA analyses on Pleistocene samples from subtropical regions and provide a framework for Proboscidean evolution.
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This comment is a brief response to the bibliographic review made by Gómez Coutouly in this issue of PaleoAmerica. We reaffirm that the anthropic nature of the Pleistocene sites in the southeast of Piauí has already been demonstrated. Based on this, we show how many skeptics with mainstream thinking reproduce a scientific ideology regarding the peopling of the Americas.
Article
The exceptional levels of biodiversity found today in the American tropics are the outcome of tens of millions of years of evolution, shaped by the tumultuous geological history of the region, its heterogeneous habitats, climate change, ecological interactions and, in recent millennia, human influence. Although our understanding of diversity patterns and their underlying processes grows steadily in breadth and depth, Neotropical biodiversity is rapidly breaking down. Here, I contrast the long-term evolution of Neotropical biodiversity with its recent and rapid deterioration due to anthropogenic factors. I consider the impacts of the early arrival of humans to the region and the modern intensification of land-use change (primarily driven by agriculture) and other drivers of biodiversity loss, such as direct exploitation, invasive species and climate change. Together, these threats have led to 33% of all Neotropical species for which sufficient data are available being currently threatened with extinction. I outline emerging opportunities for conservation and restoration under the post-2020 Global Biodiversity Framework and call for urgent action from the biodiversity community, for the benefit of people and nature.
Article
Bones of recent mammals in the Amboseli Basin, southern Kenya, exhibit distinctive weathering characteristics that can be related to the time since death and to the local conditions of temperature, humidity and soil chemistry. A categorization of weathering characteristics into six stages, recognizable on descriptive criteria, provides a basis for investigation of weathering rates and processes. The time necessary to achieve each successive weathering stage has been calibrated using known-age carcasses. Most bones decompose beyond recognition in 10 to 15 yr. Bones of animals under 100 kg and juveniles appear to weather more rapidly than bones of large animals or adults. Small-scale rather than widespread environmental factors seem to have greatest influence on weathering characteristics and rates. Bone weathering is potentially valuable as evidence for the period of time represented in recent or fossil bone assemblages, including those on archeological sites, and may also be an important tool in censusing populations of animals in modern ecosystems.
Article
In the late 1920s outside a sleepy remote New Mexico village, prehistory was made. Spear points, found embedded between the ribs of an extinct Ice Age bison at the site of Folsom, finally resolved decades of bitter scientific controversy over whether the first Americans had arrived in the New World in Ice Age times. Although Folsom is justly famous in the history of archaeology for resolving that dispute, for decades little was known of the site except that it was very old. This book for the first time tells the full story of Folsom. David J. Meltzer deftly combines the results of extensive new excavations and laboratory analyses from the late 1990s, with the results of a complete examination and analysis of all the original artifacts and bison remains recovered in the 1920s - now scattered in museums and small towns across the country. Using the latest in archaeological method and technique, and bringing in data from geology and paleoecology, this interdisciplinary study provides a comprehensive look at the adaptations and environments of the late Ice Age Paleoindian hunters who killed a large herd of bison at this spot, as well as a measure of Folsom's pivotal role in American archaeology.