Early hominin landscape use
Public release date: 1-Jun-2011
Contact: Silke Streiber
So far, ranging and residence patterns amongst early hominins have been indirectly inferred from morphology, stone tool sourcing, comparison to living primates and phylogenetic models. An international team of researchers including Sandi Copeland, Vaughan Grimes and Michael Richards of the Max Planck Institute for Evolutionary Anthropology in Leipzig/Germany have now investigated landscape use in Australopithecus africanus (with fossils from sites dating between 2.8-2.0 million years ago) and Paranthropus robustus (with fossils from sites dating between 1.9-1.4 million years ago) from the Sterkfontein and Swartkrans cave sites in South Africa using strontium isotope analysis. This method helps identify the geological substrate on which an animal lived during tooth mineralization. (Nature, June 2nd, 2011)
The researchers show that a high proportion of small, but not large, hominin teeth had non-local strontium isotope compositions. Given the relatively high levels of sexual dimorphism in early hominins, the smaller teeth probably represent females, indicating that females were more likely than males to disperse from their natal (i.e. where they were born) groups. This is similar to the dispersal pattern found in chimpanzees, bonobos, and many human groups, but dissimilar to that of most gorillas and other primates.
Established paleontological and archaeological techniques provide little tangible evidence for how early hominins used and moved across landscapes. For example, home range size has been estimated based on a rough correlation with body mass, and models of early hominin dispersal have relied on behaviors common among hominoids and presumed to be present in a common ancestor. "However, the highly uncertain nature of such reconstructions limits our understanding of early hominin ecology, biology, social structure, and evolution", says Sandi Copeland of the Max Planck Institute for Evolutionary Anthropology.
Copeland and colleagues have now used a geochemical proxy, strontium isotope analysis of tooth enamel, to investigate early hominin landscape use. Strontium is ingested and incorporated in trace quantities into mammalian teeth. First, the researchers determined strontium isotopes in plant specimens that were collected within a 50 km radius of the Sterkfontein and Swartkrans caves in order to establish the background of biologically available strontium across the region. They then sampled a series of hominin tooth crowns by employing a relatively new method for measuring strontium isotopes in teeth that is called laser ablation multicollector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS). This method is almost non-destructive as it leaves only tiny traces on the enamel surface. The researchers found that although there is no significant difference between the proportion of non-locals in P. robustus (36 %) and A. africanus (25 %), there are significant differences between subsets of hominins defined by tooth size.
"The strontium isotope data suggest differences in landscape use between males and females", says Sandi Copeland and explains: "Because strontium was incorporated into the teeth before adulthood, when the hominins were probably travelling with their mothers, the data are unlikely to reflect differences in foraging areas between adult males and adult females. Rather, the strontium isotopes probably indicate that females preferentially moved away from residential groups".
The hominins' female but not male dispersal pattern is similar to the one found in chimpanzees, bonobos, and many human groups, but dissimilar to that of most gorillas and other primates. This suggests that early hominin social structure was not like that of gorillas in which one or few males dominate groups of females.
The small proportion of non-local large hominins could indicate that male australopiths had small home ranges, which would be surprising given that the evolution of bipedalism is commonly attributed to the need to move over large distances. The results could also imply that male australopiths preferred the types of resources found on dolomite landscapes. This study was the first to apply this method to early fossil hominins, and lays the groundwork for future studies of other fossil species, including Australopithecus and Paranthropus in East Africa, and later hominins belonging to our genus Homo.
The following institutions contributed to this study: Max Planck Institute für Evolutionary Anthropology, Leipzig, Germany; University of Colorado, Boulder, USA; Texas A&M University, College Station, USA; Oxford University, Oxford, UK; University of Cape Town, Cape Town, South Africa; University of Zurich, Zurich, Switzerland; Memorial University, St. John's, Canada; University of British Columbia, Vancouver, Canada.
Original publication: Sandi R. Copeland, Matt Sponheimer, Darryl J. de Ruiter, Julia A. Lee-Thorp, Daryl Codron, Petrus J. le Roux, Vaughan Grimes & Michael P. Richards
Strontium isotope evidence for landscape use by early hominins
Nature, 02 June 2011, doi:10.1038/nature10149
Egypt's Revolution May Save Neolithic Site That Holds Nation's Oldest Evidence Of Agriculture
Posted: 06/ 2/11 11:21 AM ET
LAKE QARUN, Egypt (Reuters) – Egypt's popular uprising may have arrived just in time to save a Neolithic site that holds the country's oldest evidence of agriculture and could yield vital clues to the rise of Pharaonic civilization.
The site lies in a protected nature reserve along the shore north of Lake Qarun that until recently had remained virtually untouched, even though it lies only 70 km (43.50 miles) from Cairo, Egypt's fast-expanding capital.
A month before the protests that toppled President Hosni Mubarak erupted in January, the Egyptian government carved 2.8 square kilometers of prime land from the reserve and awarded it to property developer Amer Group for a tourist resort.
Since Mubarak was ousted, three government ministers who sat on a committee that approved the sale have been jailed while they battle corruption charges not related to the Amer deal.
One of them, Housing Minister Ahmed el-Maghrabi, told Reuters in January that archaeology officials had given the re-development the necessary green light.
Egypt's archaeology chief now says that was untrue.
"I did not give any permission to anyone. The excavations are not finished," Zahi Hawass, head of the Supreme Council for Antiquities, told Reuters.
Property developers have come under increasing public scrutiny for their land purchases from Mubarak's government, and some firms have relinquished tracts of land.
Egyptian conservation groups have decried the Amer deal, saying it was done without proper oversight and that the arrival of large numbers of holidaymakers would wreak heavy damage to a wide swathe of the delicate desert landscape.
"This is the thin end of the wedge. It is the destruction of Egyptian natural heritage for future generations." said Ali Fahmi, director of the conservation group Friends of Lake Qarun. "It sets a precedent in desecrating a protected area."
Egypt's cabinet in 1989 declared 1,110 square km north of the lake a nature protectorate, an area that also contains unique geology, Pharaonic basalt quarries from the Old Kingdom and fossils of early whales and primates.
Archaeologists say the remains of rain-based Neolithic farming in the reserve may hold vital clues to a technological leap that led to irrigation-based farming along the Nile.
Around 4,000 BC, humans occupying a strip along the northern shore of the lake seized a window of only a few centuries of rainfall to grow grain in previously inhospitable desert, archaeologists say.
"We have the evidence of the earliest agriculture activity in Egypt. So it's before the Pharaohs, it's before the early dynastic period when Egypt becomes a state," said Willeke Wendrich, an archaeology professor at the University of California in Los Angeles.
"What we have on the north shore of Fayoum is something unique worldwide. What we have is a Neolithic landscape which, because it's desert, has not been overbuilt," she said in an interview.
Khaled Saad, department manager for prehistory at Egypt's Supreme Council for Anquities (SCA), said that four years ago the Tourism Ministry decided it wanted to build hotels and tourist attractions on a 20 square km (7.723 sq mile) tract stretching 10 km along the lake's northern shoreline.
It formed a committee to approve designating the land for development that included Prime Minister Ahmed Nazif, Tourism Minister Zoheir Garranah, Maghrabi and other officials, Saad said.
In December, the Tourism Development Authority (TDA), which is under the Tourism Ministry, awarded Amer Group the land under a 99-year concession, charging $28,000 in the first year, rising to an annual $92,000 in the fourth to 10th years.
Maghrabi said in early January that the SCA had brought in archaeologists to survey the area before the project went ahead.
"It has been completely cleared by the department of antiquities. We made sure of that," Maghrabi told Reuters at the time. "This project was approved several years ago but no progress was going to be made until the department of antiquities finished their work. And they did finish their work."
But Hawass of the antiquities council said the work was still ongoing and he was now demanding a fresh assessment.
"Two weeks ago I asked Khaled Saad to come to me with a report to tell me as an archaeologist what he thinks. And now I asked him that we will appoint a large committee of archaeologists to decide the future of the land," Hawass said.
Saad said the survey mentioned by Maghrabi took place between March 2009 and October 2010 and was designed to see if there were antiquities on the site.
"I proved that there were," he said.
The site holds a wealth of prehistoric remains from mid-Mesolithic period 200,000 years ago to the Pharaonic period and later, said Saad.
They also found the remains of 24 ancient whales that swam in the region's waters 42 million years ago, including one belonging to an entirely new species.
Weindrich said further research in the area is crucial to cast light on the origins of Egyptian civilization.
She said agriculture probably arrived late in Egypt because the technology in use elsewhere in the Near East did not fit with the climate, at least until the short period of rainfall in the Neolithic period.
"We have a big research project going on looking at the climate change in that period," she said.
The Neolithic farming community that appeared around six millennia ago had little material to build with and left no sign of permanent buildings or structures, she said.
"They probably lived in some sort of reed matting huts. But what we do see is a whole pattern on the surface of fireplaces for different purposes -- to make pottery, for the fish, to roast their meat. From that pattern we're trying to understand their activities," Wendrich said.
As the moisture disappeared, the desert winds blew away most of the topsoil. Stone tools, pottery and bones once held in soil a meter deep were now concentrated in a thin surface layer.
"There's a howling wind coming from the north, which means the sand blows away, but the heavy things don't," Wendrich said.
"It's great because we can see it, but it's not so great because if you remove the top centimeter, it's gone forever. That's the precarious situation we're dealing with at the moment."
Shortly after the Neolithic period, irrigation began spreading along the Nile Valley.
"By that time, people were looking at different ways for continuing what they by then they were used to doing for a number of centuries," said Wendrich.
Copyright 2011 Thomson Reuters.
English Heritage Press Release
3,700BC: BRITAIN’S FIRST CONSTRUCTION BOOM
- Landmark Dating Research Narrows Margin of Error
From Centuries to Decades -
EMBARGOED UNTIL 00:01 6TH JUNE 2011
A ground-breaking scientific dating project led by English Heritage and the University of Cardiff has succeeded to date prehistoric features down to a margin of decades instead of centuries. By applying this method to a type of early Neolithic earthwork called causewayed enclosures, it has revealed that Britain experienced a frenetic period of monument building in the decades after 3,700BC, with the country’s first big monuments being erected some one thousand years before Stonehenge was created.
Causewayed enclosures are known prehistoric features, but up to now it has been thought that they spread slowly across Britain over five centuries. But this research reveals that this new class of huge monuments spread rapidly all over southern Britain in a short span of 75 years, starting from the Thames Estuary through Kent and Sussex, and then west, on an intense scale that was not apparent before.
The new knowledge that this happened in a flurry within two to three generations will revolutionise the way prehistory is understood and studied not only in Britain but around the world.
Dr Alex Bayliss, scientific dating expert at English Heritage, said: “Until now, because of imprecise dates and long time scales, prehistory has been dominated by processes rather than events. By dating these enclosures more accurately, we now know that something happened quite specifically some 5,700 years ago; the speed with which it took place has completely overturned our perception of prehistory.
“What is more interesting is that we found that some enclosures, such as Maiden Castle in Dorset were used only for a few decades, while others such as Hembury in Devon and Windmill Hill were used repeatedly over several centuries. For the first time, this allows important questions about choice and behaviour to be asked. By giving early human societies this level of detail and generational perspective, we are beginning to get a sense of prehistory in terms of who did what when.”
This is the remarkable result of a dating technique that analyses each radiocarbon date of organic materials collected at a particular site within a complex and exacting statistical model that takes into account the sequence of archaeological deposits obtained from the site. This has yielded much more precise construction dates of around 40 enclosures, some even narrowed down to decades. Windmill Hill, for example, was previously thought to be built circa 3700 - 3100 BC, but this new technique reveals that it was constructed in 3700 - 3640 BC – narrowing the span from six centuries down to six decades.
Causewayed enclosures, made up of concentric rings of ditches and banks, the largest of which can span 300 metres in diameter, are most populous in southern Britain but they are also found in Ireland and in Europe. They are best described as special arenas where large communities gathered and feasted from time to time. Unlike long barrows which pre-date them and were smaller, enclosures are not primarily burial sites and their size and complexity suggest that they have strong regional importance.
Some 90 causewayed enclosures are known to exist in Britain but traces of them are now hard to detect; among the more visible ones are at Windmill Hill and Knap Hill near Avebury and Whitesheet Hill near Salisbury.
More accurate dating also shows that causewayed enclosures were created when Neolithic society had advanced beyond the pioneering phase. Between 4,100BC and 3,800BC, people from Europe first settled in England and typical practices such as cereal cultivation, animal domestication, and the use of pottery, leaf arrowheads, flint mines and rectangular timber buildings were first established westwards across Britain. The vast amount of labour and resources involved in constructing causewayed enclosures could indicate that they were social symbols of an increasingly connected but also competitive society that emerged later around 3,700BC along with more intensive exchange networks, perhaps larger cattle herds and social hierarchy.
Evidence for violence like burnt ramparts and people killed by arrowheads typical of the time has also been uncovered by the research in some enclosures, such as Crickley Hill in Gloucestershire and Maiden Castle and Hambledon Hill in Dorset. This further supports the theory that by the time enclosures were built, Neolithic societies had evolved from being simple and egalitarian when feuds between individuals had been more common, to become more complex and competitive.
Professor Alasdair Whittle of Cardiff University said: “With more accurate dating, the Neolithic period is no longer the sleepy, hazy swathe of time where it is the default position to lump everything together. This research fundamentally challenges the notion that little happened among our Stone Age farmers. We can now think about the Neolithic period in terms of more rapid changes, constant movement of people and fast diffusion of ideas. We can also populate our imagination with generations and communities of people making different choices.
“This dating programme has far-reaching significance beyond the early Neolithic monuments in southern Britain. We can now think about Neolithic history anywhere in the world – ideas, events and people at specific times over 5,000 years ago.”
Gathering Time: dating the early Neolithic enclosures of southern Britain and Ireland is a research project funded by English Heritage and the Arts and Humanities Research Council. A monograph by Alasdair Whittle, Alex Bayliss and Frances Healy that marks the completion of this eight-year project is published by Oxbow Books.
Download images here: https://picasaweb.google.com/101554616913588617820/NeolithicDatingResearch?authkey=Gv1sRgCMD_26OCsobtRQ&feat=directlink
For further press information please contact Renee Fok, English Heritage Communications, on 020 7973 3297 or at firstname.lastname@example.org
Notes to editors:
What is radiocarbon dating and Bayesian statistically modelling?
Prehistorians till now have only been able to assign the people whom they study to imprecise times. Radiocarbon dating (the measure of decaying carbon in the remains of once living things) has been the most important method available to archaeologists for more than 50 years, and in the last 20 years this method has been refined by high-precision calibration based on wood dated by dendro-chronology (tree-ring dating). On its own, this method provides reliable date measurements typically spanning 250 years or more, but precise dates are not possible.
With the Gathering Time project, a new radiocarbon dating revolution has begun. The idea is to further pinpoint radiocarbon dates by taking into account other contextual information. Existing measurements are “checked” against a complex sequence of stratigraphic and archaeological data obtained from the same site in a sophisticated scientific process called Bayesian statistical modelling that can only be powered by advanced computers such as the CONDOR system at Cardiff University. The result is much more precise dating, some to within a few decades. In the Gathering Time project, this method was applied to date 40 causeway enclosures and analyse more than 1,800 radiocarbon dates from other Neolithic sites.
Marlborough mound mystery solved – after 4,400 years
Hill in Wiltshire school grounds nicknamed Silbury's little sister revealed as important neolithic monument
guardian.co.uk, Tuesday 31 May 2011 19.06 BST
For generations, it has been scrambled up with pride by students at Marlborough College. But the mysterious, pudding-shaped mound in the grounds of the Wiltshire public school now looks set to gain far wider acclaim as scientists have revealed it is a prehistoric monument of international importance.
After thorough excavations, the Marlborough mound is now thought to be around 4,400 years old, making it roughly contemporary with the nearby, and far more renowned, Silbury Hill.
The new evidence was described by one archeologist, an expert on ancient ritual sites in the area, as "an astonishing discovery". Both neolithic structures are likely to have been constructed over many generations.
The Marlborough mound had been thought to date back to Norman times. It was believed to be the base of a castle built 50 years after the Norman invasion and later landscaped as a 17th-century garden feature. But it has now been dated to around 2400BC from four samples of charcoal taken from the core of the 19 metre-high hill.
The samples prove it was built at a time when British tribes were combining labour on ritual monuments in the chalk downlands of Wiltshire, including Stonehenge and the huge ditches and stone circle of Avebury.
History students at the college will now have the chance to study an extraordinary example just a stone's throw from their classroom windows. Malborough's Master Nicholas Sampson said: "We are thrilled at this discovery, which confirms the long and dramatic history of this beautiful site and offers opportunity for tremendous educational enrichment."
The Marlborough mound has been called "Silbury's little sister", after the more famous artificial hill on the outskirts of Avebury, which is the largest manmade prehistoric hill in Europe.
Marlborough, at two-thirds the height of Silbury, now becomes the second largest prehistoric mound in Britain; it may yet be confirmed as the second largest in Europe.
Jim Leary, the English Heritage archeologist who led a recent excavation of Silbury, said: "This is an astonishing discovery. The Marlborough mound has been one of the biggest mysteries in the Wessex landscape. For centuries, people have wondered whether it is Silbury's little sister, and now we have an answer. This is a very exciting time for British prehistory."
The dating was carried out as part of major conservation work amid concerns that tree roots could be destabilising the structure.
No cheese for Neolithic humans in France
May 31, 2011
By Elizabeth Weise, USA TODAY
An excavation of a southern French burial site from about 3,000 B.C. shows that the modern humans who expanded into the area from the Mediterranean lived in patrilocal communities and did not have the genetic mutation that allowed later Europeans to digest fresh milk.
Scientists analyzed DNA extracted from the bones of 53 people buried in Cave I of the Treilles, located in the Grands Causses region at Saint-Jean-et-Saint-Paul, Aveyron in France. They were able to get useful information from 29 of those samples, 22 men, two women ad five for whom it was impossible to determine sex. Most of them appeared to be closely related, with two of them having a 99.9979% probability of being father and son and two others having a 99.9985% probability of being siblings.
The researchers were able to deduce from their findings that the peoples in this region of France were of a genetic type more closely related to Basque and Spanish populations than current western European populations. They were also more closely related to peoples in Cyprus, Portugal, Turkey, Italy and Lebanon.
None of them carried the gene for lactase persistence that is believed to have first evolved around 5,500 BC in Central Europe and which allowed humans to drink fresh milk after they are weaned.
The absence of the genetic variation probably shows that the Treilles people most likely came from agricultural-pastoral Mediterranean cultures that drank fermented milk and had an economy based on sheep and goat farming.
The paper is published in this week's edition of the journal Proceedings of the National Academy of Science.
Ancient DNA reveals male diffusion through the Neolithic Mediterranean route
Marie Lacana,b,1, Christine Keysera,b, François-Xavier Ricauta, Nicolas Brucatoa, Francis Duranthona, Jean Guilainec, Eric Crubézya, and Bertrand Ludesa,b
+ Author Affiliations
aLaboratoire d'Anthropologie Moléculaire et Imagerie de Synthèse, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5288, 31073 Toulouse, France;
bLaboratoire d'Anthropologie Moléculaire, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5288, Institute of Legal Medicine, University of Strasbourg, 67085 Strasbourg, France; and
cCentre de Recherche sur la Préhistoire et la Protohistoire de la Méditerranée, École des Hautes Etudes en Sciences Sociales, 31500 Toulouse, France
Edited by Colin Renfrew, University of Cambridge, Cambridge, United Kingdom, and approved May 2, 2011 (received for review January 19, 2011)
The Neolithic is a key period in the history of the European settlement. Although archaeological and present-day genetic data suggest several hypotheses regarding the human migration patterns at this period, validation of these hypotheses with the use of ancient genetic data has been limited. In this context, we studied DNA extracted from 53 individuals buried in a necropolis used by a French local community 5,000 y ago. The relatively good DNA preservation of the samples allowed us to obtain autosomal, Y-chromosomal, and/or mtDNA data for 29 of the 53 samples studied. From these datasets, we established close parental relationships within the necropolis and determined maternal and paternal lineages as well as the absence of an allele associated with lactase persistence, probably carried by Neolithic cultures of central Europe. Our study provides an integrative view of the genetic past in southern France at the end of the Neolithic period. Furthermore, the Y-haplotype lineages characterized and the study of their current repartition in European populations confirm a greater influence of the Mediterranean than the Central European route in the peopling of southern Europe during the Neolithic transition.
↵1To whom correspondence should be addressed. E-mail: email@example.com.
Author contributions: M.L. designed research; M.L. performed research; F.D. contributed new reagents/analytic tools; M.L., F.-X.R., and N.B. analyzed data; and M.L., C.K., F.-X.R., N.B., J.G., E.C., and B.L. wrote the paper.
Archeological Discoveries in Aleppo Dating back to 4th and 11th Centuries BC
May 29, 2011
The Syrian-Polish archeological expedition has finished its excavation works for the current year at the site of Tal al-Qaramel on the right bank of the Euphrates River, 25 km to the west of Aleppo.
Chairman of Aleppo Antiquities and Museums Department, Nadim Faqash, said that the expedition started its systematic excavation works at Tal al-Qaramel in 1999.
Faqash added that the archeological findings unearthed by the expedition are considered one of the most important archeological discoveries in the world as they provided significant information on the first human settlement phase and the shift from the life of hunting to the stage of building houses and villages.
He indicated that Tal al-Qaramel is one of the most ancient archeological villages in Syria and in the world.
The archeological sites in Aleppo receive wide attention by many of the archeological expeditions from different universities across the world due to the cultural prosperity they have witnessed in various ages.
For his part, Chairman of Archeological Excavation Division at Aleppo Antiquities and Museums Department, Yusef Kanjo, said that the excavation works led to discovering important archeological monuments such as circular houses carved in the ground whose walls have been rebuilt with stones.
He added that the height of the unearthed houses was estimated at about one meter, and at their center the expedition discovered fireplaces whose floor equipped with high technology represented in using various organic materials, indicating that the building of the walls and roofs was completed through using wood.
He pointed out that the number of the unearthed houses during the excavation season reached four, whose diameter ranged from 2 to 3 meters, adding that this gathering of houses indicates that there was a village, the houses of which were built according to the same architectural style and date back to the mid 11th century BC.
He said that the findings prove that there was human settlement at the bottom of the most ancient circular houses which date back to the 4th century BC.
Roman ship had on-board fish tank
Hand-operated pump would have kept catch alive during long trips.
Published online 31 May 2011 | Nature | doi:10.1038/news.2011.335
A Roman ship found with a lead pipe piercing its hull has mystified archaeologists. Italian researchers now suggest that the pipe was part of an ingenious pumping system, designed to feed on-board fish tanks with a continuous supply of oxygenated water. Their analysis has been published online in the International Journal of Nautical Archaeology1.
Historians have assumed that in ancient times fresh fish were eaten close to where they were caught, because without refrigeration they would have rotted during transportation. But if the latest theory is correct, Roman ships could have carried live fish to buyers across the Mediterranean Sea.
The wrecked ship, which dates from the second century AD, was discovered six miles off the coast of Grado in northeastern Italy, in 1986. It was recovered in pieces in 1999 and is now held in the Museum of Underwater Archaeology in Grado. A small trade ship around 16.5 metres long, the vessel was carrying hundreds of vase-like containers that held processed fish, including sardines and salted mackerel.
Carlo Beltrame, a marine archaeologist at the Ca' Foscari University of Venice in Italy, and his colleagues have been trying to make sense of one bizarre feature of the wreck: a lead pipe near the stern that ends in a hole through the hull. The surviving pipe is 1.3 metres long, and 7–10 centimetres in diameter.
The team concludes that the pipe must have been connected to a piston pump, in which a hand-operated lever moves pistons up and down inside a pair of pipes. One-way valves ensure that water is pushed from one reservoir into another. The Romans had access to such technology, although it hasn't been seen before on their ships, and the pump itself hasn't been recovered from the Grado wreck.
Archaeologists have previously suggested that a piston pump could have collected bilge water from the bottom of the boat, emptying it through the hole in the hull. But Beltrame points out that chain pumps — in which buckets attached to a looped chain scooped up bilge water and tipped it over the side — were much safer and commonly used for this purpose in ancient times. "No seaman would have drilled a hole in the keel, creating a potential way for water to enter the hull, unless there was a very powerful reason to do so," he writes.
Another possible use is to pump sea water into the boat, to wash the decks or fight fires. A similar system was used on Horatio Nelson's flagship, HMS Victory, in the eighteenth and nineteenth centuries. But Beltrame and his colleagues argue that the Grado wreck wasn't big enough to make this worthwhile. They say that the ship's involvement in the fish trade suggests a very different purpose for the pump — to supply a fish tank.
The researchers calculate that a ship the size of the Grado wreck could have held a tank containing around 4 cubic metres of water. This could have housed 200 kilograms of live fish, such as sea bass or sea bream. To keep the fish alive with a constant oxygen supply, the water in the tank would need to be replaced once every half an hour. The researchers estimate that the piston pump could have supported a flow of 252 litres per minute, allowing the water to be replaced in just 16 minutes.
Tracey Rihll, a historian of ancient Greek and Roman technology at Swansea University, UK, cautions that there is no direct evidence for a fish tank. The researchers "dismiss fire-extinguisher and deck-washing functions too easily in my view", she says. But although no trace of the tank itself remains, Rihll says the pipe could have been used for such a purpose in the ship's younger days. Literary and archaeological evidence suggests that live fish were indeed transported by the Greeks and Romans "on a small but significant scale", she adds.
The first-century Roman naturalist Pliny the Elder wrote that parrotfish taken from the Black Sea were transported to the Neopolitan coast, where they were introduced into the sea. And the second- and third-century Greek writer Athenaeus described an enormous ship called the Syracousia, which supposedly had a lead-lined saltwater tank to carry fish for use by the cook.
However, a fish tank on board a small cargo ship such as the Grado wreck might mean that transport of live fish was a routine part of Roman trade, allowing the rich to feast on fish from remote locations or carrying fish shorter distances from farms to local markets.
"It would change completely our idea of the fish market in antiquity," says Beltrame. "We thought that fish must have been eaten near the harbours where the fishing boats arrived. With this system it could be transported everywhere."
Beltrame, C., Gaddi, D. & Parizzi, S. Int. J. Naut. Archaeol. doi:10.1111/j.1095-9270.2011.00317.x (2011)
Excavation at site of Roman altars find in Maryport
31 May 2011 Last updated at 08:58
Experts from Newcastle University are to begin excavating an internationally important Roman site in Cumbria.
The archaeological team is focusing on the site of a major discovery of Roman altars 141 years ago.
The site where the 17 altars were found now forms part of the Roman Maryport site at Camp Farm, which is owned by Hadrian's Wall Heritage.
It is hoped the dig, which will continue into July, will shed light on the nature of religion at the time.
Project leader, Prof Ian Haynes said: "The Maryport altars have been at the centre of international debate about the nature of religion in the Roman army for decades.
"However, we still know very little about the context in which they were originally deposited and this project represents a marvellous opportunity to further our understanding."
The altars are housed at the Senhouse Museum Trust in Maryport which commissioned the excavation.
They were found by landowner Humphrey Senhouse in 1870 and form part of a significant collection of Roman sculpture and inscriptions at the museum.
Trust chairman Peter Greggains said: "It is very exciting that we can now revisit the site where the altars were found and, with modern methods, learn more about their burial and other activity in this area more than 1,800 years ago."
Linda Tuttiett, chief executive of Hadrian's Wall Heritage, said the work was a key element in understanding the development of Roman activities in Maryport.