Category Archives: News

Woolly mammoth (Mammuthus primigenius Blum.) and its environment in northern Europe during the last glaciation

Woolly mammoth (Mammuthus primigenius Blum.) and its environment in northern Europe during the last glaciation

P. Ukkonen, K. Aaris-Sørensen, L. Arppe, P.U. Clark, L. Daugnora, A.M. Lister, L. Lõugas, H. Seppä, R.S. Sommer, A.J. Stuart, P. Wojtal, I. Zupiņš

Quaternary Science Reviews
Volume 30, Issues 5-6, March 2011, Pages 693-712

Abstract

Woolly mammoths were large, herbivorous, cold-adapted mammals of the Late Pleistocene. The diet and habitat requirements of the species set certain constraints on the palaeoenvironments it could occupy. The relationship between the mammoth’s shifting range and changing environments can be explored using independent data on ice sheet configuration, temperature, and vegetation, provided the locality and age of the fossil remains can be validated. Here we present a comprehensive record of occurrence of the woolly mammoth in the circum-Baltic region of northern Europe during the last glaciation, based on a compilation of radiocarbon-dated remains. The record shows that the mammoth was widespread in northern and north-eastern Europe during Marine Isotope Stage 3 (MIS 3), at 50,000–30,000 calibrated years ago (50–30 ka). The presence of the species up to 65°N latitude supports the restriction of the Scandinavian Ice Sheet (SIS) during MIS 3. The widest distribution range round 30 ka was followed by a decline that led to the disappearance of mammoths from the area during the maximum extent of the SIS, from 22 to 18 ka. The woolly mammoth re-colonized the Baltic region and southern Scandinavia after the onset of the late-glacial deglaciation at 17 ka. The late-glacial record suggests a markedly fluctuating population changing its range in tune with the rapid environmental changes. The last appearance of mammoth in our study region was in Estonia during the Younger Dryas (Greenland Stadial 1; GS1) at about 12 ka. The two major periods of occurrence during MIS 3 and the late-glacial stadial suggest that mammoth had a wide tolerance of open to semi-open tundra and steppe-tundra habitats with intermediately cold climate, whereas the 22–18 ka disappearance suggests a major southward and/or eastward retreat in response to extremely cold, glacial conditions near the SIS margin. The final regional extinction correlates with the re-forestation during the rapid warming at the Younger Dryas–Holocene boundary.

How cold was it for Neanderthals moving to Central Europe during warm phases of the last glaciation?

Grzegorz Skrzypek, Andrzej Wiśniewski, Pauline F. Grierson
Quaternary Science Reviews
Volume 30, Issues 5-6, March 2011, Pages 481-487

Abstract

Precise estimates of mean annual temperature (MAT) for when Neanderthals occupied Central Europe are critical for understanding the role that climatic and associated environmental factors played in Neanderthal migrations and in their ultimate extinction. Neanderthals were continuously present in the relatively warm regions of southern and Western Europe in the Pleistocene but only temporarily settled Central Europe (CE), presumably because of its colder and less hospitable climate. Here, we present a new approach for more spatially and temporally accurate estimation of palaeotemperatures based on the stable oxygen isotope composition of phosphates extracted from animal teeth found at sites linked directly to concurrent Neanderthal occupation. We provide evidence that Neanderthals migrated along the Odra Valley of CE during warmer periods throughout the Upper Pleistocene. The MATs during these migrations were about 6.8 °C for the warm phase of Oxygen Isotope Stage OIS 5a–d (prior to the OIS4 cold event) at not, vert, similar115–74,000 yr BP and about 6.3 °C during the early OIS 3 warm phase not, vert, similar59–41,000 yr BP. Our results show that temperatures during these phases peaked 2–4 °C above longer term estimates from ice cores and pollen records. We argue that our approach can provide valuable insights into evaluating the role of climate in human migration patterns in the Pleistocene.

News flash: Bird fingers 

"Embryological Evidence Identifies Wing Digits in Birds as Digits 1, 2, 
and 3"

Koji Tamura, Naoki Nomura, Ryohei Seki, Sayuri Yonei-Tamura, and Hitoshi
Yokoyama

Science 11 February 2011:
Vol. 331 no. 6018 pp. 753-757
DOI: 10.1126/science.1198229

Abstract:

The identities of the digits of the avian forelimb are disputed. Whereas
paleontological findings support the position that the digits correspond 
to digits one, two, and three, embryological evidence points to digit 
two, three, and four identities. By using transplantation and 
cell-labeling experiments, we found that the posteriormost digit in the 
wing does not correspond to digit four in the hindlimb; its progenitor 
segregates early from the zone of polarizing activity, placing it in the
domain of digit three specification. We suggest that an avian-specific 
shift uncouples the digit anlagen from the molecular mechanisms that 
pattern them, resulting in the imposition of digit one, two, and three 
identities on the second, third, and fourth anlagens.

Cheers!!

--Mikko

This foot was made for walking 

The discovery that Australopithecus had arched feet suggests this human
ancestor had already abandoned life in the trees

http://www.guardian.co.uk/science/2011/feb/10/fossil-foot-bone-ancestors-walking

The transition to full-time terrestrial bipedality is a hallmark of human
evolution. A key correlate of human bipedalism is the development of
longitudinal and transverse arches of the foot that provide a rigid
propulsive lever and critical shock absorption during striding bipedal
gait. Evidence for arches in the earliest well-known Australopithecus
species, A. afarensis, has long been debated. A complete fourth metatarsal
of A. afarensis was recently discovered at Hadar, Ethiopia. It exhibits
torsion of the head relative to the base, a direct correlate of a
transverse arch in humans. The orientation of the proximal and distal ends
of the bone reflects a longitudinal arch. Further, the deep, flat base and
tarsal facets imply that its midfoot had no ape-like midtarsal break.
These features show that the A. afarensis foot was functionally like that
of modern humans and support the hypothesis that this species was a
committed terrestrial biped.

http://www.sciencemag.org/content/331/6018/750.abstract

--Laura

The Southern Route “Out of Africa”: Evidence for an Early Expansion of Modern Humans into Arabia

The Southern Route “Out of Africa”:
Evidence for an Early Expansion
of Modern Humans into Arabia

Simon J. Armitage,1 Sabah A. Jasim,2 Anthony E. Marks,3 Adrian G. Parker,4
Vitaly I. Usik,5 Hans-Peter Uerpmann6*

The timing of the dispersal of anatomically modern humans (AMH) out of Africa is a fundamental question in human evolutionary studies. Existing data suggest a rapid coastal exodus via the Indian Ocean rim around 60,000 years ago. We present evidence from Jebel Faya, United Arab Emirates, demonstrating human presence in eastern Arabia during the last interglacial. The tool kit found at Jebel Faya has affinities to the late Middle Stone Age in northeast Africa, indicating that technological innovation was not necessary to facilitate migration into Arabia. Instead, we propose that low eustatic sea level and increased rainfall during the transition between marine isotope stages 6 and 5 allowed humans to populate Arabia. This evidence implies that AMH may have been present in South Asia before the Toba eruption

Science 28 January 2011:
Vol. 331 no. 6016 pp. 453-456
DOI: 10.1126/science.1199113

See also a discussion paper in Nature:

Archaeology: Trailblazers across Arabia
Michael D. Petraglia
Nature
Volume
470,
50–51
(03 February 2011)
DOI: 10.1038/470050a

Stop the Press!! – A Pterosaur with an Egg 

http://www.sciencemag.org/content/331/6015/321.full

Junchang Lü, David M. Unwin, D. Charles Deeming, Xingsheng Jin, Yongqing Liu
and Qiang Ji

An Egg-Adult Association, Gender, and Reproduction in Pterosaurs

Science 21 January 2011:
Vol. 331 no. 6015 pp. 321-324
DOI: 10.1126/science.1197323

Abstract:

A sexually mature individual of Darwinopterus preserved together with an egg
from the Jurassic of China provides direct evidence of gender in pterosaurs
and insights into the reproductive biology of these extinct fliers. This new
find and several other examples of Darwinopterus demonstrate that males of
this pterosaur had a relatively small pelvis and a large cranial crest,
whereas females had a relatively large pelvis and no crest. The ratio of egg
mass to adult mass is relatively low, as in extant reptiles, and is
comparable to values for squamates. A parchment-like eggshell points to
burial and significant uptake of water after oviposition. This evidence for
low parental investment contradicts the widespread assumption that
reproduction in pterosaurs was like that of birds and shows that it was
essentially like that of reptiles.

--Mikko

News-flash: A new basal theropod from the Valley of the Moon 

Hi,

review: http://www.sciencemag.org/content/331/6014/134.full

article: http://www.sciencemag.org/content/331/6014/206.full

Ricardo N. Martinez, Paul C. Sereno, Oscar A. Alcober, Carina E. Colombi,
Paul R. Renne, Isabel P. Montañez and Brian S. Currie:
A Basal Dinosaur from the Dawn of the Dinosaur Era in Southwestern Pangaea.

Science 14 January 2011:
Vol. 331 no. 6014 pp. 206-210
DOI: 10.1126/science.1198467

--Mikko

News-flash: Ammonite lifestyles and structure 

Fresh information about ammonite lifestyles, diet, and structure.

http://www.sciencemag.org/content/331/6013/70.full

Isabelle Kruta, Neil Landman, Isabelle Rouget, Fabrizio Cecca and Paul
Tafforeau, 2011:
The Role of Ammonites in the Mesozoic Marine Food Web Revealed by Jaw
Preservation.
Science 7 January 2011: Vol. 331 no. 6013 pp. 70-72, DOI:
10.1126/science.1198793



--Mikko

Giant fossil bird found on ‘hobbit’ island of Flores

Fossils of the genus Leptoptilos from the Pleistocene of Liang Bua, Flores, Indonesia, belong to a new species of giant marabou stork, Leptoptilos robustus sp. nov. This giant bird, estimated at 1.80 m in length, was similar in dimensions to extant Leptoptilos dubius, except for the tibiotarsus.  An evolutionary lineage is proposed in which a volant L. dubius-like ancestor in the Middle Pleistocene evolved into the Late Pleistocene L. robustus on Flores, with a concomitant reduction of the ability to fly and an increase in body size. The large body size and terrestrial lifestyle of L. robustus are responses to an unbalanced, insular environment with abundant prey items and a lack of mammalian carnivores, and emphasize the extraordinary nature of the Homo floresiensis fauna.

In the news:

http://news.bbc.co.uk/earth/hi/earth_news/newsid_9261000/9261713.stm

The paper:

http://onlinelibrary.wiley.com/doi/10.1111/j.1096-3642.2010.00616.x/full

The Evolution of Maximum Body Size of Terrestrial Mammals

http://www.sciencemag.org/content/330/6008/1216.full

The Evolution of Maximum Body Size of Terrestrial Mammals

Felisa A. Smith, Alison G. Boyer, James H. Brown, Daniel P. Costa, Tamar
Dayan, S. K. Morgan Ernest, Alistair R. Evans, Mikael Fortelius, John L.
Gittleman, Marcus J. Hamilton, Larisa E. Harding, Kari Lintulaakso, S.
Kathleen Lyons, Christy McCain, Jordan G. Okie, Juha J. Saarinen, Richard M.
Sibly, Patrick R. Stephens, Jessica Theodor, and Mark D. Uhen:

The Evolution of Maximum Body Size of Terrestrial Mammals

–Science: Vol. 330, no. 6008, pp. 1216-1219
26 November 2010, DOI: 10.1126/science.1194830

Abstract

The extinction of dinosaurs at the Cretaceous/Paleogene (K/Pg) boundary was
the seminal event that opened the door for the subsequent diversification of
terrestrial mammals. Our compilation of maximum body size at the ordinal
level by sub-epoch shows a near-exponential increase after the K/Pg. On each
continent, the maximum size of mammals leveled off after 40 million years
ago and thereafter remained approximately constant. There was remarkable
congruence in the rate, trajectory, and upper limit across continents,
orders, and trophic guilds, despite differences in geological and climatic
history, turnover of lineages, and ecological variation. Our analysis
suggests that although the primary driver for the evolution of giant mammals
was diversification to fill ecological niches, environmental temperature and
land area may have ultimately constrained the maximum size achieved.

-Mikko Haaramo