Friday, January 15, 2010

Missing 500-Years of Loggias, Porticos Described.

Porticos are roof-covered structures supported by columns. (Credit: iStockphoto/Nils Kahle)
Source: ScienceDaily
ScienceDaily (Jan. 14, 2010) — Using texts and images, a University of Arkansas researcher has for the first time reconstructed the time when the use of porticos -- roof-covered structures supported by columns -- gave way to loggias, or recessed porticos.
In an article in the Journal of the Society of Architectural Historians, architecture professor Kim Sexton accounts for the time between the 7th and 12th centuries when there are no surviving porticos. In European history, loggias represented more than just interesting architectural features. They also served important cultural functions.
"It's important because we had porticos in Roman times, and then they come back in the Renaissance," she said. "It's unaccounted time -- what happened in between?"
Sexton argues that they returned to prominence because different ethnic groups used them "to display their judicial systems." As court proceedings were held outdoors, "they used different styles to frame that." At times there was German law and at other times, Roman law, and certain loggia announced each style.
"In this competitive kind of culture, they start to use the portico again," Sexton said. "From there it comes back into prominence in the Renaissance and late medieval Italy."
Loggias were "used to display activities that were kind of new, and maybe people felt unsure about their value. So that they wanted to display there was something good about the justice system." She compares it to television today, as a powerful medium that can influence behavior.
Loggias and porticos have long interested Sexton. "They seem at once so transparent in their function because they seem like simple shelters," she said. "But then, why did they come to be built with such magnificent architecture by some of the best architects of the Renaissance?"
Sexton discovered images in several medieval sources -- the center of a gem, illustrations of the book of Psalms, illuminations from law codes and encyclopedias. The article's most important image, which is in color on the journal's cover, shows the only known instance of a king in a loggia where a trial is actually in progress.
"If you see them empty, you're not getting what it's about," she said of loggias. "You have to see it when they're full of activity."
Sexton is associate professor of architecture, Fay Jones School of Architecture, University of Arkansas.
Story Source:
Adapted from materials provided by
University of Arkansas, Fayetteville, via Newswise.

Wednesday, January 13, 2010

Shipworm Threatens Archaeological Treasures.

The shipworm, Teredo navalis, infesting a pier pole in the Swedish province of Bohuslän.
Source: ScienceDaily
ScienceDaily (Jan. 13, 2010) — The dreaded shipworm is moving into the Baltic Sea, threatening artefacts of the area's cultural heritage. Researchers at the University of Gothenburg, Sweden, suspect that the unfortunate spread is due to climate change, and are currently involved in an EU project to determine which archaeological remains are at risk.
The shipworm is capable of completely destroying large maritime archaeological finds in only 10 years, and while it has avoided the Baltic Sea in the past, since it does not do well in low salinity water, it can now be spotted along both the Danish and German Baltic Sea coasts.

Malmö landmark infested:
'The shipworm has for example attacked shipwrecks from the 1300s off the coast of Germany, and we are also starting to see its presence along the Swedish coast, for example at the Ribersborg cold bath house in Malmö,' says Christin Appelqvist, doctoral student at the Department of Marine Ecology, University of Gothenburg.

Effect of climate change:
Appelqvist and her colleagues believe that the development may be due to climate change. In short, the increased water temperature may help the shipworms to become adapted to lower salinity. The group is part of the EU project WreckProtect, a cooperative effort to assess which archaeological treasures are at risk. The project includes researchers from Sweden, Denmark and the Netherlands, as well as experts from France and Germany.

Covering the shipwrecks:
One of the objectives is to develop methods to protect the shipwrecks, for example by covering them with geotextile and bottom sediment, and another is to try to predict to which areas the shipworm is likely to spread in the future. The researchers say there are some 100 000 well-preserved shipwrecks in the Baltic Sea.
'Around 100 wrecks are already infested in the Southern Baltic, but yet it hasn't even spread past Falsterbo. We know it can survive the salinity of the Stockholm archipelago, although it needs water with higher salinity than that to be able to reproduce,' says Appelqvist.
Story Source:
Adapted from materials provided by
University of Gothenburg.

Monday, January 11, 2010

Use of Body Ornamentation Shows Neanderthal Mind Capable of Advanced Thought.

Source: ScienceDaily
ScienceDaily (Jan. 11, 2010) — The widespread view of Neanderthals as cognitively inferior to early modern humans is challenged by new research from the University of Bristol published in Proceedings of the National Academy of Sciences.
Professor João Zilhão and colleagues examined pigment-stained and perforated marine shells, most certainly used as neck pendants, from two Neanderthal-associated sites in the Murcia province of south-east Spain (Cueva de los Aviones and Cueva Antón). The analysis of lumps of red and yellow pigments found alongside suggest they were used in cosmetics. The practice of body ornamentation is widely accepted by archaeologists as conclusive evidence for modern behaviour and symbolic thinking among early modern humans but has not been recognised in Neanderthals -- until now.
Professor Zilhão said: "This is the first secure evidence that, some 50,000 years ago -- ten millennia before modern humans are first recorded in Europe -- the behaviour of Neanderthals was symbolically organised."
A Spondylus gaederopus shell from the same site contained residues of a reddish pigmentatious mass made of lepidocrocite mixed with ground bits of hematite and pyrite (which, when fresh, have a brilliant black, reflective appearance), suggesting the kind of inclusion 'for effect' that one would expect in a cosmetic preparation.
The choice of a Spondylus shell as the container for such a complex recipe may relate to the attention-grabbing crimson, red, or violet colour and exuberant sculpture of these shells, which have led to their symbolic- or ritual-related collection in a variety of archaeological contexts worldwide.
A concentration of lumps of yellow colorant from Cueva de los Aviones (most certainly the contents of a purse made of skin or other perishable material) was found to be pure natrojarosite -- an iron mineral used as a cosmetic in Ancient Egypt.
While functionally similar material has been found at Neanderthal-associated sites before, it has been explained by stratigraphic mixing (which can lead to confusion about the dating of particular artefacts), Neanderthal scavenging of abandoned modern human sites, or Neanderthal imitation without understanding of behaviours observed among contemporary modern human groups.
For example, controversy has surrounded the perforated and grooved teeth and decorated bone awls found in the Châtelperronian culture of France. In earlier work, Professor Zilhão and colleagues have argued they are genuine Neanderthal artefacts which demonstrate the independent evolution of advanced cognition in the Neanderthal lineage.
However, the Châtelperronian evidence dates from 40,000 to 45,000 years ago, thus overlapping with the period when anatomically modern human people began to disperse into Europe (between 40,000 and 42,000 years ago) and leaving open the possibility that these symbolic artifacts relate, in fact, to them.
Professor Zilhão said: "The evidence from the Murcian sites removes the last clouds of uncertainty concerning the modernity of the behaviour and cognition of the last Neanderthals and, by implication, shows that there is no reason any more to continue to question the Neanderthal authorship of the symbolic artefacts of the Châtelperronian culture.
"When considering the nature of the cultural and genetic exchanges that occurred between Neanderthals and modern humans at the time of contact in Europe, we should recognise that identical levels of cultural achievement had been reached by both sides."
Accurate radiocarbon dating of shell and charcoal samples from Cueva de los Aviones and Cueva Antón was crucial to the research. The dating was undertaken at the University of Oxford's Radiocarbon Accelerator Unit.
Dr Thomas Higham, Deputy Director of the Radiocarbon Unit in the School of Archaeology said: "Dating samples that approach the limit of the technique, at around 55,000 years before present, is a huge challenge. We used the most refined methods of pre-treatment chemistry to obtain accurate dates for the sites involved by removing small amounts of more modern carbon contamination to discover that the shells and charcoal samples were as early as 50,000 years ago."
Story Source:
Adapted from materials provided by
University of Bristol.
Journal Reference:
1.João Zilhão, Diego E. Angelucci Ernestina Badal-García, Francesco d%u2019Errico, Floréal Daniel, Laure Dayet, Katerina Douka, Thomas F. G. Higham, María José Martínez-Sánchez, Ricardo Montes-Bernárdez, Sonia Murcia-Mascarós, Carmen Pérez-Sirvent, Clodoaldo Roldán-García, Marian Vanhaeren, Valentín Villaverde, Rachel Wood, and Josefina Zapata. Symbolic use of marine shells and mineral pigments by Iberian Neandertals. Proceedings of the National Academy of Sciences, Online Jan. 11, 2010

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Sunday, January 10, 2010

Fossil Footprints Give Land Vertebrates a Much Longer History.

Source: ScienceDaily
ScienceDaily (Jan. 8, 2010) — The discovery of fossil footprints from early backboned land animals in Poland leads to the sensational conclusion that our ancestors left the water at least 18 million years earlier than previously thought.
The results of the Polish-Swedish collaboration are published online in the journal Nature.
"These results force us to reconsider our whole picture of the transition from fish to land animals," says Per Ahlberg of Uppsala University, one of the two leaders of the study.
For nearly eighty years, palaeontologists have been scouring the planet for fossil bones and skeletons of the earliest land vertebrates or "tetrapods" -- the ultimate progenitors of all later amphibians, reptiles, birds and mammals including ourselves. Their discoveries have suggested that the first tetrapods evolved relatively rapidly from lobe-finned fishes, through a short-lived intermediate stage represented by "elpistostegids" such as Tiktaalik, about 380 million years ago. But there is another potential source of information about the earliest tetrapods: the fossilized footprints they left behind.
In the new study a Polish-Swedish team describe a rich and securely dated footprint locality from Zachelmie Quarry in Poland that pushes back the origin of tetrapods a full 18 million years beyond the earliest skeletal evidence and forces a dramatic reassessment of the transition from water to land.
The trackways show that large tetrapods, up to three metres in length, inhabited the marine intertidal zone during the early Middle Devonian some 395 million years ago.
"This means not that not only tetrapods but also elpistostegids originated much earlier than we thought, because the position of elpistostegids as evolutionary precursors of tetrapods is not in doubt, and so they must have existed at least as long," says Per Ahlberg.
The elpistostegids, it seems, were not at all a short-lived transitional stage but must have existed alongside their descendants the tetrapods for at least 10 million years. The environment is also a major surprise: almost all previous scenarios for the origin of tetrapods have placed this event in a freshwater setting and have associated it with the development of land vegetation and a terrestrial ecosystem.
"Instead, our distant ancestors may first have left the water in order to feed on stranded marine life left behind by the receding tide," says Per Ahlberg.
Story Source:
Adapted from materials provided by
Uppsala University.
Journal Reference:
1.Grzegorz Niedźwiedzki, Piotr Szrek, Katarzyna Narkiewicz, Marek Narkiewicz & Per E. Ahlberg. Tetrapod trackways from the early Middle Devonian period of Poland. Nature, 2010; 463 (7277): 43 DOI:

30,000-Year-Old Child's Teeth Shed New Light on Human Evolution.

Source: ScienceDaily
ScienceDaily (Jan. 8, 2010) — The teeth of a 30,000-year-old child are shedding new light on the evolution of modern humans, thanks to research from the University of Bristol published in the Proceedings of the National Academy of Sciences.
The teeth are part of the remarkably complete remains of a child found in the Abrigo do Lagar Velho, Portugal and excavated in 1998-9 under the leadership of Professor João Zilhão of the University of Bristol. Classified as a modern human with Neanderthal ancestry, the child raises controversial questions about how extensively Neanderthals and modern human groups of African descent interbred when they came into contact in Europe.
'Early modern humans', whose anatomy is basically similar to that of the human race today, emerged over 50,000 years ago and it has long been the common perception that little has changed in human biology since then.
When considering the biology of late archaic humans such as the Neanderthals, it is thus common to compare them with living humans and largely ignore the biology of the early modern humans who were close in time to the Neanderthals.
With this in mind, an international team, including Professor Zilhão, reanalysed the dentition of the Lagar Velho child (all of its deciduous -- milk -- teeth and almost all of its permanent teeth) to see how they compared to the teeth of Neanderthals, later Pleistocene (12,000-year-old) humans and modern humans.
Employing a technique called micro-tomography which uses x-rays to create cross-sections of 3D-objects, the researchers investigated the relative stages of formation of the developing teeth and the proportions of crown enamel, dentin and pulp in the teeth.
They found that, for a given stage of development of the cheek teeth, the front teeth were relatively delayed in their degree of formation. Moreover, the front teeth had a greater volume of dentin and pulp but proportionally less enamel than the teeth of recent humans.
The teeth of the Lagar Velho child thus fit the pattern evident in the preceding Neanderthals, and contrast with the teeth of later Pleistocene (12,000-year-old) humans and living modern humans.
Professor Zilhão said: "This new analysis of the Lagar Velho child joins a growing body of information from other early modern human fossils found across Europe (in Mladeč in the Czech Republic, Peştera cu Oase and Peştera Muierii in Romania, and Les Rois in France) that shows these 'early modern humans' were 'modern' without being 'fully modern'. Human anatomical evolution continued after they lived 30,000 to 40,000 years ago."
The team was led by Priscilla Bayle (Muséum National d'Histoire Naturelle, France) and Roberto Macchiarelli (Université de Poitiers, France) and included Erik Trinkaus (Professor of Anthropology at Washington University, St.-Louis, Cidália Duarte (Câmara Municipal do Porto, Portugal), and Arnaud Mazurier (CRI-Biopôle-Poitiers, France).
Story Source:
Adapted from materials provided by
University of Bristol.
Journal Reference:
Priscilla Bayle, Roberto Macchiarelli, Erik Trinkaus, Cidália Duarte, Arnaud Mazurier, and João Zilhão. Dental maturational sequence and dental tissue proportions in the early Upper Paleolithic child from Abrigo do Lagar Velho, Portugal. Proceedings of the National Academy of Sciences, 2010; DOI: