9 June 2010

Who killed the iceman?

Cosmos Online
The murder of Ötzi the Iceman is perhaps the most challenging cold case in history. Archaeologists used a splay of forensic methods to piece together a detailed picture of his life – and death.
the Iceman

Ötzi the iceman was murdered more than 5,000 years ago.
HIT PLAY, above, to see an X-ray of Ötzi's chest. Credit: South Tyrol Museum of Archaeology

X-ray of Iceman's left shoulder

X-ray examination and CT scan revealed an arrowhead in Ötzi's left shoulder. Credit: South Tyrol Museum of Archaeology

It sounds like the opening to a television forensics drama. On a sunny September day in 1991, a German couple hiking through the Alps make a gruesome discovery.

Initially, the corpse partially jutting out of the melting ice is thought to be from a recent mountaineering accident. But on closer inspection, a far more stunning revelation emerges. The body is that of a murder victim; a murder that transpired five millennia ago.

Dated to around 5,300 years old, the remarkably well-preserved Neolithic Iceman came to be known as Ötzi, after the Ötztal region of the Austrian-Italian border where he was found.

In the years since his discovery, he has been subject to countless, delicate examinations. Now, three recent studies give us the most definitive account of how the Iceman came to be slain.

“The unique thing about this find is that a man has been preserved in full dress with all his equipment,” says Angelika Fleckinger, director of the South Tyrol Museum of Archaeology in Bolzano, Italy, where Ötzi resides today.

It’s not only the Iceman’s age, but the ‘wet’ nature of the mummification process that makes him so scientifically valuable, she adds. “The tissue is therefore elastic; a lucky circumstance, as some scientific examinations would otherwise have been impossible.”

“Ötzi is much older than any other glacier mummy and is a very rare case in which mummification took place by dehydration before the body became embedded in glacier ice,” say researchers led by Klaus Oeggl of the University of Innsbruck, Austria, in the journal Quaternary Science Reviews.

“Even the food residue in his digestive tract was very well preserved, and a test sample provided evidence of his diet, environment, and season of death.”

Oeggl’s team have used the remains of Ötzi’s last meals (including ibex, grains and red deer meat) and tiny traces of different pollens, to reveal his whereabouts over his last 33 hours with surprising clarity.

“Ötzi’s movements in his last days from sub-alpine regions down to the valley bottoms and then up to alpine regions again, as well as his lethal injury by an arrowhead, confirm that Ötzi’s last days were hectic and violent, which corroborates parts of [the] disaster theory,” they write.

This disaster theory, first proposed by the University of Innsbruck’s Konrad Spindler in 1995, purports that Ötzi came into conflict with others several days before his death, and sustained knife wounds to his hand. He then fled into the mountains and was in the process of fashioning a longbow and quiver of arrows to defend himself.

The precise cause of Ötzi’s death has been debated for years, but in the November 2007 issue of the Journal of Archaeological Science, a team including radiologist Paul Gostner of the Bolzano General Hospital in Italy argue that Ötzi was almost certainly killed by the stone arrowhead embedded in his shoulder.

First detected by X-ray in 2001, the severity of the injury it caused had been debated – but a full CT (computed tomography) scan of the mummy has now confirmed that the arrowhead tore through a major artery. The experts say this would have led to internal bleeding and a rapid, shock-related cardiac arrest.

So who killed the Iceman and why? Archaeological sleuths Gostner and Andreas Lippert of the University of Vienna, Austria, recently put forward a new scenario in the periodical Germania – where they report that Ötzi also received a blow to the head.

Putting together all the pieces of the puzzle from the individual motes of forensic evidence, the experts argue that Ötzi was shot in the back by a distant assailant at a lower elevation.

He was then struck on the head and fell on his back, where he died. Finally, the murderer rolled Ötzi onto his front, with his arm folded under his body, and tugged the arrowshaft from where it was lodged his back.

There the Iceman remained for over 5,000 years, with his arm twisted under his body, and his longbow still leaning against the wall of the gully. It took the melting of the Tisenjoch glacier – which had been gliding over the protected hollow – to bring poor Ötzi back into the light of day.

Specific results from the investigation:

Age: Upon examining a copper axe found with the Iceman, archaeologist Konrad Spindler immediately identified him as at least 4,000 years old. Subsequent carbon dating proved that the iceman was in fact one of the oldest mummies ever discovered and had lived some 5,300 years ago.

Hair: Ötzi’s hair fell out after he died but pieces of it were found on his clothing and at the site of his discovery. It was wavy, dark brown and about nine centimetres long. Traces of arsenic and metal within the hair shaft suggest he was involved with smelting copper.

Eyes: Ötzi’s eyes were blue. They remain today.

Teeth: Wolfgang Müller of the Australian National University in Canberra has analysed the isotopic composition of strontium, oxygen and lead in Ötzi’s teeth to show that his likely birthplace was near the modern town of Brixen, Italy – but that his adult life was spent in the neighbouring Vinschgau or Schnals valleys.

Lungs: These are blackened with soot from much time spent sitting in front of open fires.

X-ray examination and CT scan: In 2001, radiologist Paul Gostner revealed that Ötzi has a flint arrowhead embedded in his left shoulder, which was the first evidence of his murder. In 2005 a CT (computed tomography) scan showed the arrowhead had severed the left dorsal subclavian artery – a major blood vessel. Further investigations have now revealed a severe trauma to the skull and likely contusion to the brain.

Intestines: The contents, including ibex, red deer meat, grains and pollen, have been used to reconstruct the last 33 hours of Ötzi’s life. Chips of mica suggest the wheat and grains he ate had been ground down; specks of charcoal may have come from making bread and baking it in an open fire.

Hand: Ötzi’s left hand has a number of partially healed deep lacerations, likely inflicted several days before death. Experts argue that the injuries bear the mark of self-defence and suggest he was involved in conflict.

Fingernails: The first of two fingernails found at the site suggests Ötzi may have been ill. Characteristic lines across the nail suggest his immune system was compromised three times in the months prior to his death. The second nail has yet to be analysed.

Age at death: A small sample of femur bone, measured for characteristic changes that occur with age, suggest Ötzi was around 46 years of age. He was in good condition for a man of his era.

Tattoos: The body is etched with over 50 tattoos, created by rubbing charcoal into fine incisions. Fine groups of parallel lines on his back and legs may have been administered as a form of pain relief.

Injuries: Healed injuries from earlier in life include broken ribs and a cyst on his toe caused by frostbite

Forensic botany: Thirty different types of pollen have been found in Ötzi’s intestines. Particularly prevalent was that of the hop hornbeam tree, which only grows south of the Alps. It flowers in spring, suggesting a rough date of death. No less than 80 species of mosses and liverworts were also found on and around the mummy.

Intestines: The contents, including ibex, red deer meat, grains and pollen, have been used to reconstruct the last 33 hours of Ötzi’s life. Chips of mica suggest the wheat and grains he ate had been ground down; specks of charcoal may have come from making bread and baking it in an open fire.

DNA: Limited analysis of mitochondrial DNA in 1994 confirmed Ötzi is related to living inhabitants of central Europe. Albert Zink, the scientific director of the Institute for Mummies and the Iceman in Bolzano, says that much more detailed work will soon investigate both his mitochondrial and genomic DNA.

Bearskin-soled shoes: Made of various materials including deerskin and hay, Ötzi’s are the second oldest known shoes. Experiments by archaeologist Anne Reichert reveal that a leather strip running across the sole provided a surprisingly good grip on icy ground, but the soles were not waterproof. Aside from shoes, Ötzi’s other clothing included leggings, a loincloth, a belt and pouch made of calf or goat’s leather, a grass cape and a bearskin cap. The leggings would have covered only the calf and the thigh, and were secured to the belt and shoes with deerskin laces.

Copper axe: Thermal neutrons and high energy X-rays from a particle accelerator were used to non-invasively determine the structure of copper within the axe. This showed that the blade had been repeatedly sharpened, and was well used.

Flint dagger and sheath: Ötzi was found still clutching a 13-centimetre-long flint dagger – the most complete known example from that era.

John Pickrell is the former editor of Cosmos Online.

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