Ancient human remains unearthed in SW England

An ANU archaeologist has hailed her excavation of a Bronze Age burial mound in south west England a huge success with the discovery of an intact 4,000 year old human cremation as well as evidence of unaccountable activity from the medieval period on the same site.

Hendersick Barrow site, Cornwall [Credit: SEKAS]

Dr Catherine Frieman recently excavated an untouched ancient barrow near the town of Looe in South East Cornwall. Her 14 day-dig over Easter was the first time such a site in the area has been excavated to modern archaeological standards.

She said when digging began, local farmers told her they'd ploughed the field in their childhood, so she didn't expect the site to be so well preserved.

"We were so excited to find such a lot of archaeology on the site despite scores of generations of ploughing, but to find an intact clay urn buried 4,000 years ago just 25 centimetres beneath the surface is nothing short of a miracle," said Dr Frieman.

Archaeologists excavating the site [Credit: (c) SEKAS]

This and other evidence from the site has led her to conclude there was most likely a large mound over the burial which existed from prehistory well into the middle ages protecting the centre of the barrow.

"This is a sealed, intact cremation so it has the potential to tell us a lot about the cremation rite as it was practiced 4,000 years ago. We also appear to have some identifiable fragments of bone among the cremated remains so we'll potentially be able to tell a lot about the individual themselves," she said.

"We'll be able to say what gender they were, possibly their age, or an age range, and depending on the bone preservation we can conduct analyses to examine where they were from, what their diet was like, where this food was coming from and what they ate and drank as a child when their teeth were forming. This is a very beautiful, very complete burial, and we're very excited," she said.

Intact 4,000 year old cremation pot [Credit: (c) SEKAS]

Other items found include various examples of Cornish Bronze Age pottery, flint tools and two high-quality hammer stones, used to make flint tools. However, what has puzzled Dr Frieman and her team was the discovery of medieval activity on the same site.

"The site has thrown up a big mystery for us because we found what we believe is an entire - albeit crushed - medieval pot from the 12th or 13th century AD, carefully placed under a couple of layers of flat stones. It had some cooked food remains adhering to it and we don't know what it's doing there or why."

"Hundreds of years after the barrow was built, someone from the 12th or 13th century came back to this site and dug into it to bury this pot.

Bronze Age hammer stone for making flint tools [Credit: (c) SEKAS]

"At that stage there were two local monasteries in view of this site, as Looe Island was a satellite monastery of the Glastonbury Abbey, so it would be very strange to have non-Christian activity on this site. The evidence looks quite ritualistic, but what the ritual was, we don't know," she said.

The team also excavated a round house - an ancient dwelling or land marker nearby, possibly from 500 BC and are trying to deduce possible reasons for the location of the barrow.

"This was a traversed place and regularly visited over the millennia, it affords a sweeping view of the south coast of England and we know that there are a series of Bronze Age shipwrecks off this coast, so this was an important shipping highway in prehistory." 

Geophysical scan of the barrow showing area to be excavated [Credit: (c) SEKAS]

The analysis of soil, pollen, flint and other samples is underway but it will probably be a year before a comprehensive story of the find is possible.

Dr Frieman said the dig would not have been possible without the help of a team of enthusiastic and skilled volunteers from the Cornwall Archaeological Society, the tenant farmers, John and Vanessa Hutchings and the strong support of the National Trust who own and manage the site and their Regional Archaeologist James Parry.

Author: Jane Faure-Brac | Source: Australian National University [May 16, 2018]

A European origin for leprosy?

New research by an international team including scientists from the Max Planck Institute for the Science of Human History, the University of Tübingen, EPFL Lausanne and the University of Zurich has revealed that there was much more diversity in the leprosy strains circulating in Medieval Europe than previously thought. This finding, based on the sequencing of 10 new ancient genomes from the leprosy-causing bacterium Mycobacterium leprae, complicates prior assumptions about the origin and spread of the disease, and also includes the oldest M. leprae genome sequenced to date, from about 400 AD in the United Kingdom.

Skeletal remains showing evidence of leprosy from the Odense St. Jørgen cemetery in Denmark, which
was established in 1270 and existed until 1560 [Credit: Dorthe Dangvard Pedersen]

Leprosy is one of the oldest recorded and most stigmatized diseases in human history. The disease was prevalent in Europe until the 16th century and is still endemic in many countries, with over 200,000 new cases reported annually. The bacterium Mycobacterium leprae is the main cause of leprosy. Previous research on the bacterium suggested that it clusters into several strains, only two of which were present in Medieval Europe. The present study, published in the journal PLOS Pathogens, aimed to further investigate the history and origin of M. leprae by looking for genetic evidence from a large number of ancient samples from throughout Europe.

10 new ancient genomes of M. leprae dating from approximately 400-1400 AD

The current study examined approximately 90 individuals with skeletal deformations that were characteristic of leprosy, from across Europe and from time periods ranging from approximately 400 AD to 1400 AD. From these samples, 10 new medieval M. leprae genomes were fully reconstructed. These genomes represent all known strains, including strains that are today associated with different locations around the globe, including Asia, Africa and the Americas. Additionally, in this study multiple strains were often found in the same cemetery, illustrating the diversity of the leprosy strains circulating throughout the continent at the time.

Skeletal remains from Great Chesterford showing evidence of leprosy. This is the oldest
 known case of leprosy in the United Kingdom [Credit: Sarah Inskip]

"We found much more genetic diversity in ancient Europe than expected," explains Johannes Krause, senior author of the study and a director at the Max Planck Institute for the Science of Human History. "Additionally, we found that all known strains of leprosy are present in Medieval Europe, suggesting that leprosy may already have been widespread throughout Asia and Europe in antiquity or that it might have originated western Eurasia."

Oldest leprosy genome to date

One M. leprae genome reconstructed by the team was from Great Chesterford, England, and dates to between 415-545 AD. This is the oldest M. leprae genome sequenced to date and comes from one of the oldest known cases of leprosy in the United Kingdom. Interestingly, this strain is the same found in modern-day red squirrels and supports the hypothesis that squirrels and the squirrel fur trade were a factor in the spread of leprosy among humans in Europe during the medieval period.

Verena Schuenemann at the Palaeogenetics Laboratory,
University of Tuebingen [Credit: Johannes Krause]

"The dynamics of M. leprae transmission throughout human history are not fully resolved. Characterization and geographic association of the most ancestral strains are crucial for deciphering leprosy's exact origin" states lead author Verena Schuenemann of the University of Zurich. "While we have some written records of leprosy cases that predate the Common Era, none of these have yet been confirmed on a molecular level."

The abundance of ancient genomes in the current study has resulted in a new and older estimate for the age of M. leprae than previous studies, placing its age at least a few thousand years old. "Having more ancient genomes in a dating analysis will result in more accurate estimates," explains Krause. "The next step is to search for even older osteological cases of leprosy than currently available, using well-established methods for identification of potential cases."

Source: Max Planck Society [May 10, 2018]

Tiny fossils unlock clues to Earth's climate half a billion years ago

An international collaboration of scientists, led by the University of Leicester, has investigated Earth's climate over half a billion years ago by combining climate models and chemical analyses of fossil shells about 1mm long.

Brachiopod fossils used in this study. Electron microscopy allows much higher resolution imaging
of small structures than normal light microscopy [Credit: University of Leicester]

The research, published in Science Advances, suggests that early animals diversified within a climate similar to that in which the dinosaurs lived.

This interval in time is known for the 'Cambrian explosion', the time during which representatives of most of the major animal groups first appear in the fossil record. These include the first animals to produce shells, and it is these shelly fossils that the scientists used.

Scientists have long thought that the early Cambrian Period was probably a greenhouse interval in Earth's climate history, a time when there were no permanent polar ice sheets.

Until now, however, scientists have only had a sense of what the Cambrian climate was like because of the types of rock that were deposited at this time -- while it has long been believed that the climate was warm, specific details have largely remained a mystery.

Reflected light microscope images of some of the brachiopod fossils used in this study. They are not very pretty,
but they are pretty useful for scientists researching ancient climates [Credit: University of Leicester]

Data from the tiny fossil shells, and data from new climate model runs, show that high latitude (~65 °S) sea temperatures were in excess of 20 °C. This seems very hot, but it is similar to more recent, better understood, greenhouse climates like that of the Late Cretaceous Period.

Thomas Hearing, a PhD student from the University of Leicester's School of Geography, Geology and the Environment, explained: "Because scientists cannot directly measure sea temperatures from half a billion years ago, they have to use proxy data -- these are measurable quantities that respond in a predictable way to changing climate variables like temperature. In this study, we used oxygen isotope ratios, which is a commonly used palaeothermometer.

"We then used acid to extract fossils about 1mm long from blocks of limestone from Shropshire, UK, dated to between 515 -- 510 million years old. Careful examination of these tiny fossils revealed that some of them have exceptionally well-preserved shell chemistry which has not changed since they grew on the Cambrian sea floor."

Dr Tom Harvey, from the School of Geography, Geology and the Environment, added: "Many marine animals incorporate chemical traces of seawater into their shells as they grow. That chemical signature is often lost over geological time, so it's remarkable that we can identify it in such ancient fossils."

A thin section slice through the trilobite-rich Comley Limestones (Shropshire, UK) -- the rocks
 that the fossils used in this studies come from. The elongated curvy features in this image
are cross sections through trilobites, which are a group of extinct marine arthropods.
The arrow shows the "way-up" of the rock [Credit: University of Leicester]

Analyses of the oxygen isotopes of these fossils suggested very warm temperatures for high latitude seas (~65 °S), probably between 20 °C to 25 °C.

To see if these were feasible sea temperatures, the scientists then ran climate model simulations for the early Cambrian. The climate model simulations also suggest that Earth's climate was in a 'typical' greenhouse state, with temperatures similar to more recent, and better understood, greenhouse intervals in Earth's climate history, like the late Mesozoic and early Cenozoic eras.

Ultimately, these findings help to expand our knowledge of the early animals of the period and the environment in which they lived.

Thomas Hearing said: "We hope that this approach can be used by other researchers to build up a clearer picture of ancient climates where conventional climate proxy data are not available."

The research was carried out as an international collaboration involving scientists from the University of Leicester (UK), British Geological Survey (BGS; UK), and CEREGE (France). This collaboration brought together expertise in geochemistry, palaeontology and climate modelling to tackle this longstanding problem.

Source: University of Leicester [May 09, 2018]

DNA analysis confirms family burials were part of Roman life in Colchester

Bones from a Roman cemetery in Colchester have for the first time had their DNA analysed to confirm there were family burial sites in the town in the fourth century AD.

Butt Road Roman cemetery excavation [Credit: Colchester Archaeological Trust]

Essex scientists applied ancient DNA (aDNA) analysis to assess the DNA from bones from the Butt Road Roman cemetery. This cemetery is notable for spanning the transition from Roman paganism to Christianity, with north-south pagan burials overlain by a late Roman Christian cemetery in which the burials are oriented east-west.

Previous research had suggested the existence of family plots in the Christian level, although proving this definitively has proved a major difficulty. The new study, published in Frontiers in Genetics, is the first time the existence of family groupings in a Roman cemetery has been scientifically proved.

Led by Professor Nelson Fernández, the team from Essex extracted DNA from the femur bones of 29 skeletons, mostly from a large cluster of graves centred on two timber burial vaults.

Reconstruction of the church ca 350 AD [Credit: Peter Froste]

Studies of ancient DNA usually determine relationships by looking at mitochondrial DNA (mtDNA). Relationships can also be determined using HLA (human leukocyte antigen) typing which shows how closely the tissues of one person match the tissues of another person and is an effective indicator to show if someone is related. Using both approaches, the scientists found that the individuals buried within the vault complex at Butt Road were interrelated and were most likely from Roman descent.

The results also throw some light on Christian funeral practices in Roman Britain. Most of the sampled graves which were arranged around the pair of vaults are interpreted as ‘focal graves’. The results indicate that family burials could be an important focal burial characteristic, with the associated family groupings perhaps representing people of privilege within the community.

Burials at Butt Road cemetery excavated in 2012 [Credit: Dr Tim Dennis]

Professor Fernández said: “In recent years, aDNA analysis has breathed new life into archaeology as it is such a powerful research tool. It means that we have been able to for the first time scientifically prove the long-held theory that there were family burial areas at the Butt Road Roman cemetery by showing they shared the same inherited genetic markers.”

As Britain’s oldest recorded town, during the Roman period Colchester had a number of areas that were clearly used solely as cemeteries. The Butt Road Roman cemetery is one of the largest excavated Romano-British cemeteries and is associated with a church building, probably the earliest known in Britain.

Source: University of Essex [May 03, 2018]