3-D analysis of dog fossils sheds light on domestication debate

In an effort to settle the debate about the origin of dog domestication, a technique that uses 3-D scans of fossils is helping researchers determine the difference between dogs and wolves.

3D plot of PC1–3 mandible shape variation. Black: dogs, dark grey: Alaskan wolves, light grey: European wolves, 
dark red: Ivolgin fossils, green: Ust’-Polui fossils, purple: Pleistocene Alaskan wolves, cyan: 1600CE fossil dogs, 
orange: unknown Alaskan fossil canids, pink: 1600CE fossil wolf [Credit: Scientific Reports (2017)]

In the ongoing debate, one camp believes dogs were domesticated in the Paleolithic age (more than 17,000 years ago), when humans were hunter-gatherers. The other camp believes domestication occurred in the Neolithic age (17,000 to 7,000 years ago), when humans first established agriculture and civilizations.

Abby Grace Drake, a senior lecturer in the Department of Ecology and Evolutionary Biology, and her colleagues have been analyzing 3-D scans of ancient fossil canid mandibles to determine whether they belong to dogs or wolves. The answer, they find, is not so simple.

The researchers found that in the early stages of domestication, the skull changed shape but evolution of the mandible lagged behind and did not co-evolve with the skull. Their study is reported in the journal Scientific Reports.

"A lot of the fossil evidence for the date of dog domestication is based on morphological [structural] analysis of mandibles," said Drake, the paper's first author. Robert Losey, an anthropologist at the University of Alberta, Canada, is a senior co-author of the paper. "Our study shows that when you measure modern dog mandibles and wolf mandibles using 3-D measurements you can distinguish them, and yet when we looked at these fossil mandibles, they don't look like dogs or wolves."

Wolves have fairly straight mandibles while dog mandibles are curved, structural features that become evident in a 3-D scan. In a proof of principle, when analyzing the 3-D structures of mandibles of modern dogs, Drake and colleagues correctly classified 99.5 percent of the samples as being dog or wolf.

This video shows how a canid mandible changes shape and curves during its transition from wolf to dog 

[Credit: Abby Grace Drake/Cornell University]

However, 3-D analysis of fossil records from four ancient sites, two from Russia and two from Alaska, found that most of those fossil mandibles could not be classified as either dog or wolf, even though features in canid skulls from the same sites as well as other data proved that the samples were dog remains.

Other evidence also showed that these canids were domesticated: The remains were found within human dwellings, remains at both the Russian sites revealed butchery marks, indicating that they were eaten, and isotope analysis of canid and human remains from one of the sites - Ust'-Polui, in the Russian Arctic - showed canids and humans were both eating fish, and humans were feeding their canids.

Since mandibles do not appear to evolve as rapidly as the skull, the results show they are not reliable for identifying early dog fossils, Drake said.

Four of 26 fossil mandibles from Ust'-Polui, which was occupied from 250 B.C. to 150 B.C., were identified as dogs, while three of the mandibles from the site were identified as wolves.

At another site, Ivolgin, in southern Russia, occupied between 300 B.C. and 200 B.C., none of the 20 mandibles were identified as dogs, though 8 were identified as wolves. All of the skulls found at these sites, 12 from Ivolgin and five from Ust'-Polui, were clearly identified as dogs.

Canid fossils of wolves and dogs from the Alaskan sites from 1600 CE were used as controls and to compare genetic testing against the structural 3-D data.

A 2015 paper by Drake and Michael Coquerelle, an anthropologist at the University Rey Juan Carlos in Alcorcon, Spain, and a co-author on the current paper, used the 3-D technique to refute a claim that dogs existed 30,000 years ago. That claim was based on linear caliper measurements of skulls. Linear measurements are inaccurate because dog and wolf skull sizes overlap, Drake said. On the other hand, 3-D analysis of skulls uses landmarks across the skull to identify differences between dogs and wolves in the angle of the muzzle, or snout, and in the angling of the eye orbits.

"The earliest dogs I've seen in my analysis are from 7,000 to 9,000 years ago," Drake said.

Author: Lindsey Hadlock | Source: Cornell University [September 21, 2017]

Read More

Ancient Greek fortress unearthed in southern Russia

Archaeologists have unearthed a fortress in Russia’s Krasnodar Region, which was apparently founded by Greek colonists in the fifth century BC, head of the expeditions department at the Research Center for Cultural Heritage Preservation Ivan Tupalov told TASS, adding that the citadel had been found in the area where an energy bridge to Crimea is under construction.

Credit: © Vyacheslav Prokofiev/TASS

"Security work was underway in connection with the construction of the energy bridge between Rostov and Taman [the part of the energy bridge that would incorporate Crimea in Russia’s energy grid, ensuring uninterrupted power supply to the peninsula - TASS]," he said. "During excavations, an ancient fortress was unearthed. Judging by its fortifications, it was a Greek citadel founded by colonists, who came to settle the Black Sea coast… Such discoveries are not made every day," Tupalov added.

According to him, the fortress is estimated to date back 2,500 years, as it is believed to have been built approximately in the fifth century BC. Its walls were made of mud bricks, that’s why they did not last till today, but some traces can be seen in places where the ditch was and towers once stood. The citadel had an area of around eight hectares. In the seventh and eighth centuries AD, the earthern ramparts left over from its walls were turned into a burial ground, while in the past decades, the area was partly occupied by fields.

Tupalov said that scientists have yet to find answers to a lot of questions. The number of the citadel’s residents is still unknown (it can be estimated based on the number of the uncovered ceramic sherds). Another puzzling question is whether during ancient times, the Kuban River was connected to the sea by a firth or the did the Greeks build their fortress on the seashore, or did they move deep inland, which was uncommon for them.

Besides, archaeologists have found a number of noteworthy artefacts. "For instance, a bowl has been excavated which has an interesting picture of figures engaged in a dance resembling the modern Greek 'sirtaki' dance," Tupalov said. "Besides, there are various small incense burners as the Greeks were very fond of fragrances, there are also pieces of jewellery and ceramic sherds," he added.

The Greeks, who came to the territory of the present-day Kuban in the fourth century BC, established their or colonies on the sea coast. They founded the Bosporan Kingdom on the shores of the Black Sea and the Sea of Azov, spreading their civilization and peacefully coexisting with peoples living on the Taman Peninsula. In the fourth century AD, the Hun tribes drove the Greeks out of this area.

Source: TASS [September 18, 2017]

Read More

Grave of medieval 'infant prince' found in the Arctic

The grave of a 15th century infant 'prince' wearing a fur and wool 'crown' has been found in the Russian Arctic.

The burials were on the highest points of the spurs, or hillocks, on Arctic rivers 
[Credit: Alexander Tkachev, The Siberian Times]

The child, probably aged three or four, was buried with his feet trampling on reindeer bones, and a feast of newly-roasted venison interred with him as nourishment for the next life.

Archaeologists say two iron knives were attached to his belt, and he was buried on birch bark with a stock of arrowheads.

The grave was not found in burial grounds, but on its own, seen as another unusual aspect, researchers said 
[Credit: Alexander Tkachev, The Siberian Times]

The child was buried with an elaborate headdress decorated with iron rings and bronze ornaments.

Researchers believe it is unique and indicate the boy had a high status in his Arctic society which existed on the remote Gydan peninsula in the late 15th or early 16th centuries.

So far nine burials have been found, but only two opened - and more may be identified 
[Credit: Alexander Tkachev, The Siberian Times]

The child's remains were found on a spur on the Vesakoyakha River in the Siberian permafrost.

Dr Alexander Tkachev, head of the Museum of Archaeology and Ethnography of Tyumen State University, said: 'The burial was unusually rich for such a little child.

Fragment of the young child's skull [Credit: Alexander Tkachev, The Siberian Times]

'In fact, we were rather taken aback. When we dug down, we thought the grave was almost empty, but then we saw two knives and were very surprised. When we noticed the pieces of fur and woollen cloth along with the decorations - and understood it was impressive headwear - we were really shocked.'

The grave was not found in burial grounds, but on its own, seen as another unusual aspect.

The elaborate headdress - decorated with iron rings and bronze ornaments - is seen as unique and indicating 
the boy had a high status in his Arctic society [Credit: Alexander Tkachev, The Siberian Times]

Such burial sites do exist - known to the local Nenets people as 'The Road of Those Who Went To Heaven' - but graves here were simpler.

'There are no such rich kid burials, that is why we were so surprised by our finds this summer,' he said.

Archaeologists say two iron knives were attached to his belt [Credit: Alexander Tkachev, The Siberian Times]

But eight other graves have been found, all on different the spurs of Arctic rivers.

One of these is known to be a child's - a boy aged 13 or 14 was found with cross-shaped inlays of white bronze on his funeral gown, unearthed last year.

The boy was buried on birch bark with a stock of arrowheads [Credit: Alexander Tkachev, The Siberian Times]

Dr Tkachev believes the others, to be opened next year, will be children too.

One theory 'is that the youngsters were buried alone, away from their clans, because they died before being fully initiated into their polar societies,' reported The Siberian Times.

Evidence was found of fires on mounds at the graves, with venison being cooked on the bone, perhaps
as sustenance on the way to the next life [Credit: Alexander Tkachev, The Siberian Times]

The child 'prince' is from the he indigenous Sikhirtya (Siirtya) people, described as 'very small, with blond hair and light eyes'.

The researchers are to reconstruct the elaborate headdress worn by the child.

Author: Will Stewart | Source: Daily Mail [September 08, 2017]

Read More