European Seasonal and Annual Temperature Variability, Trends, and Extremes Since 1500

Abstract

Multiproxy reconstructions of monthly and seasonal surface temperature fields for Europe back to 1500 show that the late 20th- and early 21st-century European climate is very likely (>95% confidence level) warmer than that of any time during the past 500 years. This agrees with findings for the entire Northern Hemisphere. European winter average temperatures during the period 1500 to 1900 were reduced by approximately 0.5 degrees C (0.25 degrees C for annual mean temperatures) compared to the 20th century. Summer temperatures did not experience systematic century-scale cooling relative to present conditions. The coldest European winter was 1708/1709; 2003 was by far the hottest summer.

Full text

⬃0.12 for this grain is higher than any reported
to date in presolar oxide grains (30, 33, 34).
However, shell H-burning and third dredge-up
in low-mass AGB stars produce a
26
Al/
27
Al
ratio of only ⬃1.5 ⫻ 10
⫺3
in the envelope (26).
Another consideration is that the grain has to
form before dredge-up of C turns the star into a
carbon star (23). Consequently, another process
must be invoked to account for the large
26
Al/
27
Al. Previously, CBP was invoked to account
for the high
26
Al/
27
Al ratios found in a corun-
dum and a hibonite grain (34). As mentioned
already, CBP occurs in low-mass stars during
the RGB and the thermally pulsing AGB phas-
es. Although CBP alters the O and Al isotopic
abundances simultaneously, there is no correla-
tion between the two systems because the de-
crease in
18
O/
16
O is dependent on the rate of
mass circulation (M
˙
), whereas
26
Al/
27
Al de-
pends on the maximum temperature of the cir-
culated material (T
P
), which in turn depends on
depth of penetration (23). According to CBP
models for a 1.5 M
J
(solar mass) star (23),
26
Al
is abundantly produced for log T
P
⬎ 7.65, but
the large
26
Al/
27
Al observed in the presolar
silicate grain requires log T
P
⬎ 7.76 and very
deep mixing. In addition, the O isotopic com-
position of this grain requires M
˙
⬎ 10
⫺6
M
J
per year. These values for T
P
and M
˙
are feasible
in low-mass thermally pulsing AGB stars un-
dergoing CBP. It is apparent that the combined
isotopic analysis of O and Mg provides more
detailed information on deep mixing processes
than just one isotopic system would provide.
In combining the data for all presolar silicates
in IDPs (11, 12), we arrive at a total abundance of
⬃890 ppm (9). In contrast, the abundance in
Acfer 094 relative to the matrix material is ⬃40
ppm. This difference confirms that IDPs are more
primitive than any meteorite. The abundance of
circumstellar silicates in the matrix of the ordinary
chondrites Semarkona and Bishunpur has been
inferred to be ⬃15 ppm (14, 15) compared with
⬃40 ppm in Acfer 094. These ordinary chondrites
have undergone more aqueous alteration than
Acfer 094 and formed at higher temperatures.
This difference in abundance gives us a first look
at the effects of meteorite formation histories and
parent body processes on presolar grain survival.
Determination of the abundances of presolar sili-
cates in other meteorite classes will give us a
means of studying the physical conditions in dif-
ferent solar system environments. Due to the un-
usually primitive nature of Acfer 094, we do not
expect the abundance to be higher in other mete-
orites, but we still do not understand the destruc-
tive processes affecting presolar silicate grains
well enough to make this a firm prediction.
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35. We thank the reviewer for valuable comments and are
grateful to S. Amari and C. Floss for their assistance with
SEM measurements and helpful discussions. We also thank
S. Messenger and F. Stadermann for developing the soft-
ware for processing the isotopic images. Supported by
NASA grants NAG5-10426 and NAG5-11545.
Supporting Online Material
www.sciencemag.org/cgi/content/full/303/5663/1496/
DC1
Materials and Methods
Table S1
References
5 December 2003; accepted 30 January 2004
European Seasonal and Annual
Temperature Variability, Trends,
and Extremes Since 1500
Ju¨rg Luterbacher,
1,2
* Daniel Dietrich,
3
Elena Xoplaki,
2
Martin
Grosjean,
1
Heinz Wanner
1,2
Multiproxy reconstructions of monthly and seasonal surface temperature fields
for Europe back to 1500 show that the late 20th- and early 21st-century
European climate is very likely (⬎95% confidence level) warmer than that of
any time during the past 500 years. This agrees with findings for the entire
Northern Hemisphere. European winter average temperatures during the period
1500 to 1900 were reduced by ⬃0.5°C (0.25°C for annual mean temperatures)
compared to the 20th century. Summer temperatures did not experience sys-
tematic century-scale cooling relative to present conditions. The coldest Eu-
ropean winter was 1708/1709; 2003 was by far the hottest summer.
Detailed insight into high-resolution temporal
and spatial patterns of climate change during
previous centuries is essential for assessing the
degree to which late 20th-century changes may
be unusual in the light of preindustrial natural
climate variability (1–3). Climate change at sea-
sonal to annual resolutions for recent centuries
has been highlighted in a number of studies,
which have included climate modeling experi-
ments with estimated natural and anthropogenic
radiative-forcing changes (4–6) and empirical
hemispheric or global reconstructions. Such re-
constructions are based either on natural ar-
chives only (such as ice cores, tree rings, spe-
leothems, varved sediments, and subsurface
temperature profiles obtained from borehole
measurements) or on multiproxy networks that
amalgamate natural proxy indicators with cli-
mate information obtained from early instru-
mental and documentary evidence (7–14). A
number of these reconstructions support the
conclusion that the warmth of the late 20th
century is likely unprecedented in the Northern
1
National Center of Competence in Research (NCCR) Cli-
mate,
2
Institute of Geography, Climatology, and Meteorol-
ogy,
3
Department of Mathematical Statistics and Actuarial
Science, University of Bern, CH–3012 Bern, Switzerland.
*To whom correspondence should be addressed. E-
mail: juerg@giub.unibe.ch
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Hemisphere in the past 1000 years and cannot
be explained by natural forcings alone (15).
Hemispheric and global temperature recon-
structions do not provide information about re-
gional-scale variations, such as the intrinsic sea-
sonal patterns of climate change as they have
occurred in Europe during the past centuries.
The few European-scale temperature reconstruc-
tions (7, 16–19) have revealed information for the
winter or summer half-year or for annual to mul-
tiannual mean values. Changes in the full annual
cycle have typically not been addressed, because
of the limited year-round information provided by
most natural climate proxy data (2, 20).
Regional and temporal high-resolution re-
constructions also illuminate key climatic fea-
tures, such as regionally very hot or cool sum-
mers and very mild or cold winters, that may be
masked in a hemispheric or global reconstruc-
tion (15, 16). Thus, regional studies and recon-
structions of climate change are critically im-
portant when climate impacts are evaluated
(21–23). Extremes at regional scales, such as the
hot summer of 2003 in many European areas,
exhibit much larger amplitudes than extremes at
the global scale, and they may thus markedly
affect the local to regional natural environment,
society, and economy, including most vital as-
pects such as water supply and agriculture.
Here we present a new gridded (0.5° ⫻ 0.5°
resolution) reconstruction of monthly (back to
1659) and seasonal (from 1500 to 1658) tem-
perature fields for European land areas (25°W
to 40°E and 35°Nto70°N) (19). This recon-
struction is based on a comprehensive data set
that includes a large number of homogenized
and quality-checked instrumental data series, a
number of reconstructed sea-ice and tempera-
ture indices derived from documentary records
for earlier centuries, and a few seasonally re-
solved proxy temperature reconstructions from
Greenland ice cores and tree rings from Scan-
dinavia and Siberia (fig. S1 and tables S1 and
S2). We discuss the evolution of European winter,
summer, and annual mean temperatures for more
than 500 years in the context of estimated uncer-
tainties, emphasizing the trends, spatial patterns
for extreme summers and winters, and changes in
both extreme and mean conditions.
Fig. 1A presents the winter [December
through February (DJF)] European surface tem-
perature variations since 1500 (relative to the
1901 to 1995 average) and the 95% confidence
range [⫾2 standard error (SE)] (19). The un-
certainty is larger in the earlier reconstructions.
From the 16th to the beginning of the 18th
century, the two SEs of the filtered wintertime
series are in the order of 1.3°C, and they reduce
to 0.4°C from 1865 onwards. The larger uncer-
tainties in the earlier centuries are mainly due to
a smaller number of uniformly distributed in-
strumental records (none before 1659), but are
also due to fewer proxy series and additional
uncertainties in the documentary data (20, 24–
26) and natural proxies (2, 27).
Except for two short periods around 1530
and 1730, European winters were generally
colder than those of the 20th century. The cold-
est multidecadal winter periods were experi-
enced during the late 16th century, during the
last decades of the 17th century, and at the end
of the 19th century (⌬T ⫽⬃–0.8°C, where ⌬T
is the change from the 1901 to 1995 average).
The winter of 1708/1709 was the coldest in
record (⌬T ⫽ –3.6°C) and probably related to a
negative North Atlantic Oscillation (NAO) in-
dex (28–30). We reconstructed spatial anomaly
patterns of the three individual months and the
average of winter 1708/1709 (Fig. 2A). January
and February contributed most to the overall cold
when temperatures over large parts of Europe and
western Russia were more than 7°C below aver-
age. Except for the northernmost part of our study
area, the reconstruction is reliable. Independent
climate evidence from different European areas
confirms the existence of strong negative temper-
ature anomalies (supporting online text).
We calculated the return period of a
European-wide event such as the coldest winter
of 1708/1709. This calculation is based on fit-
ting a spline function and is sensitive to the
trend over the period 1750 to 2002 and the
assumption of Gaussian distributed residuals
(19). We obtained a return period of 200 to 500
years for winter conditions from 1750 to ⬃1900.
The warming of the 20th century leads to an
increase in the return period, which amounts to
more than 100,000 years at the turn of the 21st
century (fig. S2A). However, the uncertainties of
the estimates are large, and the return periods
should be considered with caution (fig. S2A).
Fig. 2C presents anomaly (1901 to 1995
average subtracted) composites and the corre-
sponding standard deviations (SDs) for the ten
coldest European winters, excluding 1708/
1709. The anomaly composite resembles the
1708/1709 winter. It indicates continental cold
with the largest deviations and highest variabil-
ity over northern and eastern Europe, western
Fig. 1. (A) Winter (DJF), (B)
summer (JJA), and (C) an-
nual averaged-mean Euro-
pean temperature anomaly
(relative to the 1901 to
1995 calibration average)
time series from 1500 to
2003, defined as the aver-
age over the land area
25°W to 40°E and 35°N to
70°N (thin black line). The
values for the period 1500
to 1900 are reconstruc-
tions; data from 1901 to
1998 are derived from
(44). The post-1998 data
stem from (45); Goddard
Institute for Space Studies
(GISS) NASA surface tem-
perature analysis is given
ona1°⫻ 1° resolution
(46). Temperature data
from (44) and (45) are very
similar and correlate at
0.98 for each season within
the common period 1901
to 1998 for the chosen
area; they do not indicate
any absolute bias. The
thick red line is a 30-year
Gaussian low-pass filtered
time series. Blue lines show
the ⫾2 SEs of the filtered
reconstructions on either
side of the low-pass fil-
tered values. The red hori-
zontal lines are the 2-SD
line of the period 1901 to
1995. The warmest and
the coldest winters, sum-
mers, and years are denot-
ed in blue and red, respec-
tively. The winter y axis
uses a different scale. Re-
con., reconstructed; CRU,
Climatic Research Unit (44);
TT, temperature; wrt, as
compared to.
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Russia, and Scandinavia, and positive anoma-
lies over Iceland and parts of Turkey. It shows
the well-known seesaw in winter temperature
between Greenland/Iceland and Europe (31),
associated with large-scale variations in the
atmosphere–ocean–sea ice system.
A strong winter warming trend was ob-
served between 1684 and 1738. The linear trend
for this period amounts to ⫹0.32°C ⫾ 0.18°C
per decade. (All confidence ranges on trends
are calculated at the 95% confidence level and
are statistically significant.) Such an intense
increase in European winter temperature over a
comparable time period was not observed else-
where in the 500-year record. The spatial trend
map for this 55-year period (Fig. 3) indicates an
increasing warming gradient from southwestern
to northeastern Europe, with maximum values
(0.8°C per decade) over Scandinavia and the Bal-
tic region. A strong trend toward decreased winter
ice severity in the Western Baltic for the same
period has been found (32), thus supporting our
findings with independent climate information.
The large-scale European warming during
this time may have been caused by different
processes. In a stratosphere-resolving general
circulation model (22, 33), decadal-scale conti-
Fig. 2. (A) Monthly (D, J, and F) and seasonal
(DJF) European temperature anomaly (relative
to 1901 to 1995 average) patterns for the
coldest winter (1708/1709). The reconstruc-
tions are based on time series from central
England (United Kingdom, instrumental), Paris
(France, instrumental), Berlin (Germany, in-
strumental) and De Bilt ( The Netherlands,
instrumental). For Switzerland, southern Ger-
many, Hungary, Greece, and Portugal, temper-
ature estimations are available based on high-
resolution documentary evidence. Icelandic
sea ice conditions around the northern, east-
ern, and southern coasts were also used (fig.
S1 and table S2). The Reduction of Error (RE)
values (a measure of common variance) (47)
are plotted on the seasonal winter pattern.
The RE values were calculated from calibration
over the 1901 to 1960 period, with the same
available predictors as for winter 1708/1709,
and were verified over the period 1961 to
1995. [An RE of ⫹1 is a perfect reconstruction,
and RE ⬎ 0 is better than climatology with
reconstruction skill (19)]. (B) As (A), but for
the hottest summer 2003. The data for 2003
have been provided by (45). (C) Anomaly
(1901 to 1995 average subtracted) composite
and SD of the ten coldest European winters
(excluding winter 1708/1709) and ten hottest summers (excluding summer 2003) over the period 1500 to 2003. Anomalies and SDs are given in °C. White grid cells
indicate missing values. Extremely cold European winters are usually related to negative NAO situations and persistent high pressure systems centered over northern
Europe or Scandinavia or to the westward extension of the Siberian anticyclone connected with continental easterly to northerly flow (48). Hot European summers
are generally connected with a large number of persistent high-pressure systems over the continent, which may result in strong subsidence and/or warm air advection
from the southwest. Dry soils can support the conversion of the surface radiation into heat (at the expense of evapotranspiration).
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nental winter temperatures before the industrial
era appear to respond differently to solar and
volcanic forcings. Although both enhanced ir-
radiance and large eruptions lead to continental
warming, solar changes affect continental
scales much more strongly, through forcing of
the NAO or Arctic Oscillation (AO) [i.e., en-
hanced (reduced) solar irradiance causes a shift
toward the high (low) index NAO/AO state].
Thus, solar forcing seems to dominate over
volcanic eruptions, which induce a more homo-
geneous hemisphere-wide cooling at decadal
time scales. Increased solar irradiance at the end
of the 17th century and through the first half of
the 18th century might have induced such a
shift toward a high NAO/AO index, which
agrees with independent proxy NAO recon-
structions (28, 29). It is well known that the
NAO exerts a dominant influence on winter-
time temperature over much of Europe, though
the strength of the relationship can change over
time and region (34). We confirm this behavior
for the pre-instrumental period (35). Further-
more, North Atlantic sea surface temperatures
(36) and tropical variability (37) are both rele-
vant for NAO dynamics and might also be
important for explaining the European winter
warming during the late 17th and early 18th
centuries. However, missing ocean data for this
period impede testing of this hypothesis. Solar
irradiance estimates stayed at relatively high
values until the turn of the 19th century, where-
as NAO index reconstructions and European
winter temperatures indicate lower values.
Mechanisms responsible for such European
winter cooling are still under debate.
The linear winter temperature trend for
the 20th century (1901 to 2000) is ⫹0.08°C
⫾ 0.07°C per decade. The winter 1989/1990
(⌬T ⫽⫹2.4°C) and the decade 1989 to 1998
(⌬T ⫽⫹1.2°C) were the warmest since 1500.
The period 1989 to 1998 was almost two SEs
warmer than the second warmest (non-
overlapping) decade (1733 to 1742, ⌬T ⫽
⫹0.45°C), thus was very likely (95% confi-
dence level) warmer than any other decade
since 1500. At the multidecadal time scale (30-
year averages), the winters between 1973 and
2002 were likely (85% probability) the warmest
30-year period of the last half-millennium.
Winter 2002/2003, however, was 0.4°C colder
than the 1901 to 1995 average. Recent findings
(38) show that the effect of anthropogenic forc-
ing is detectable on Eurasian winter tempera-
tures over the period 1950 to 1999.
European summer [June through August
(JJA)] temperatures are shown in Fig. 1B. The
two-SE limits decrease from 0.7°C at 1500 to
0.2°C toward the end of the reconstruction period.
A notable increase in reliability occurs in the first
part of the 18th century, when instrumental data
become available. Reconstructed European sum-
mers from ⬃1530 to 1570 were slightly warmer
than the 1901 to 1995 average. A marked feature
in the summer series is the higher temperatures
from ⬃1750 until the second half of the 19th
century, including the second hottest summer of
1757 (⌬T ⫽⫹1.6°C). Importantly, possible inho-
mogeneities in the instrumental data before the
mid-19th century cannot be fully excluded and are
still a matter of discussion. For example, summer
temperature observations from Stockholm and
Uppsala (Sweden) could have been positively bi-
ased by as much as 0.7 to 0.8°C before ⬃1860,
likely because of insufficient radiation protection
of the thermometers (39). Reconstructed Northern
Hemisphere summer temperatures (12) during
this period remained below the 20th-century av-
erage. This underlines the fundamental difference
between late 20th-century warming at the hemi-
spherical scale and preindustrial regional warm
episodes that were as warm or even warmer than
today, but were limited in their geographical ex-
tent and scattered in their timing (15, 40).
From 1757 onwards, there was a summer
cooling trend (– 0.06°C ⫾ 0.02°C per decade)
until the beginning of the 20th century, with
1902 as the coolest summer in the entire record.
During the 20th century, the instrumental sum-
mer data depict first a warming trend until
1947, followed by a cooling trend until 1977.
Subsequently, an exceptionally strong, unprec-
edented warming is observed (a linear trend of
⫹0.7°C ⫾ 0.20°C per decade) that featured
very likely the hottest summer decade 1994 to
2003. The European summer temperatures
show other multidecadal periods with compa-
rable, though less strong, warming trends (1731
to 1757, 0.42°C ⫾ 0.17°C per decade; 1923 to
1947, 0.45°C ⫾ 0.23°C per decade, respective-
ly). The summer of 2003 exceeded 1901 to
1995 European summer temperatures by
around 2°C (4 SDs). Taking into account the
uncertainties in our reconstructions, it appears
that the summer of 2003 was very likely warm-
er than any other summer back to 1500.
The return period of a European-scale sum-
mer event exceeding 2°C (relative to the 1901
to 1995 average) was calculated with the same
methodology (varying trend over time) as for
the 1708/1709 winter (19). The return period is
more than 5000 years for mid-18th century
summer conditions (fig. S2B). It increases no-
ticeably to millions of years at the turn of the
20th century and decreases to less than 100
years for the most recent summers (19). Schär
et al. (41) found a much higher return period in
their analysis of central European temperature.
The differences might be related to the use of
different methods, such as varying trend over
time versus specified climatology, or of another
base period connected with a different SD, as
well as the different geographical area (regional
versus continental). However, both estimates
contain large uncertainties and should not be
overinterpreted (fig. S2B) (41).
Results from regional climate model simu-
lations (41, 42) (under the Special Report on
Emissions Scenarios A2, transient greenhouse-
gas scenario) suggest that about every second
summer will be as hot or even hotter than 2003
by the end of the 21st century (2071 to 2100).
All individual summer months of 2003 (Fig.
2B) experienced significantly higher-than-
normal temperatures, with maximum values
over western and central Europe. The anomaly
(1901 to 1995 average subtracted) composite of
the ten hottest European summers (excluding
2003) (Fig. 2C) shows a monopole pattern with
the most positive anomalies and highest vari-
ability over northeastern Europe.
The smoothed curve of European annual
mean temperatures (Fig. 1C) clearly points to
cooler conditions throughout the earlier re-
constructed centuries. The 19th century
(⌬T ⫽ – 0.32°C) was the coldest of the last
half-millennium. This agrees with recon-
structions for the Northern Hemisphere (9).
The coldest decadal periods were observed in
the second part of the 19th century, at the end
of the 17th century, and ⬃1600 (⌬T ⬃
– 0.6°C), although with an increasing degree
of uncertainty the earlier in time.
Decadal-scale continental annual temperature
changes during preindustrial times appear to
be driven primarily by solar variability (22,
33), although prolonged periods of volcanism
could have also contributed to European
cooling. Deforestation (6) may also be rele-
vant for lower European annual temperatures
in the late 19th century.
Fig. 3. Winter temperature trends
(°C per decade) from 1684 to
1738. The thick solid lines repre-
sent the 95% and 99% confidence
level (error probability 0.05 and
0.01), respectively, using a Mann-
Kendall trend test. Except for the
Mediterranean area, the warming
trends are statistically significant
over the whole of Europe.
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The 20th century (1901 to 2000) was the
warmest since 1500. There was a strong warm-
ing trend of ⫹0.08°C ⫾ 0.03°C per decade
within the 20th century. The last 30 years (1974
to 2003, ⌬T ⫽⫹0.43°C) were ⬃0.45°C higher
than the second warmest 30-year periods (1722
to 1751 and 1750 to 1779) of the reconstruc-
tions. When we consider the uncertainties of
earlier periods, the late 20th- and early 21st-
century European warmth at multidecadal (30-
year) scale is very likely unprecedented for
more than the past 500 years. The nine warmest
European years on record have occurred since
1989. The year 1989 (⌬T ⫽⫹1.3°C) and the
decade 1994 to 2003 (⌬T ⫽⫹0.84°C) were
very likely the warmest for more than half
a millennium.
Our ⬎500-year continental-scale surface tem-
peratures provide evidence of current European
climate change. Comparing recent temperature
changes with those of the past and taking into
account reconstruction uncertainties, we show that
the late 20th- and early 21st-century warmth very
likely exceeds that of any time during at least the
past 500 years. The high-resolution reconstruc-
tion also sheds light on the spatial structure of
regional temperature anomalies and extremes
back in time. Furthermore, our temperature es-
timates provide a key test of the General Cir-
culation Model’s continental and seasonal re-
sponse to different forcings (22, 43).
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Global Climate Data (Version 1, gridded temperature
and precipitation) has been supplied by the Climate
Impacts LINK Project (DEFRA, contract EPG 1/1/154) on
behalf of the Climatic Research Unit, University of East
Anglia. Supported by the Swiss National Science Foun-
dation (NCCR Climate) (J.L.); the Fifth Framework Pro-
gramme of the European Union [Project SOAP (Simu-
lations, Observations and Paleoclimate Data: Climate
Variability over the last 500 Years)] (E.X.); and the
Bundesamt fu¨r Bildung und Wissenschaft under con-
tract 01.0560 (B.B.W.).
Supporting Online Material
www.sciencemag.org/cgi/content/full/303/5663/1499/
DC1
Materials and Methods
SOM Text
References and Notes
Figs. S1 and S2
Tables S1 and S2
20 November 2003; accepted 5 February 2004
Late Miocene Teeth from Middle
Awash, Ethiopia, and Early
Hominid Dental Evolution
Yohannes Haile-Selassie,
1
* Gen Suwa,
2
Tim D. White
3
Late Miocene fossil hominid teeth recovered from Ethiopia’s Middle Awash
are assigned to Ardipithecus kadabba. Their primitive morphology and wear
pattern demonstrate that A. kadabba is distinct from Ardipithecus ramidus.
These fossils suggest that the last common ancestor of apes and humans had
a functionally honing canine–third premolar complex. Comparison with
teeth of Sahelanthropus and Orrorin, the two other named late Miocene
hominid genera, implies that these putative taxa are very similar to A.
kadabba. It is therefore premature to posit extensive late Miocene hominid
diversity on the basis of currently available samples.
The phylogenetic status of the earliest
hominid genera Sahelanthropus, Orrorin,
and Ardipithecus (1–6 ) and the definition
of the family Hominidae (7–10) are in de-
bate. By what derived characters should
the hominid (1, 11) clade be recognized?
Bipedality might be an arbiter of hominid
status, but “bipedality” involves a large
and complex set of anatomical traits and is
not a dichotomous character. Femora at-
tributed to Orrorin tugenensis at ⬃5.8
million years ago (Ma) constitute the ear-
liest postcranial evidence for early hominid
bipedality (2, 12). However, the O. tu-
genensis femora are different from those of
later hominids such as Australopithecus
afarensis (13). Indeed, some question
1
Cleveland Museum of Natural History, 1 Wade Oval
Drive, Cleveland, OH 44106, USA.
2
The University
Museum, The University of Tokyo, Bunkyo-Ku, Hongo,
Tokyo 113-0033, Japan.
3
Department of Integrative
Biology and Laboratory for Human Evolutionary Stud-
ies, Museum of Vertebrate Zoology, University of
California, Berkeley, CA 94720, USA.
*To whom correspondence should be addressed. E-
mail: yhailese@cmnh.org
R EPORTS
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