People ate mammoth; Dogs got reindeer

Artist's depiction of cave painting of primitive hunt

Biogeologists have shown how Gravettian people shared their food 30,000 years ago.

Předmostí I is an exceptional prehistoric site located near Brno in the Czech Republic. Around 30,000 years ago it was inhabited by people of the pan-European Gravettian culture, who used the bones of more than 1000 mammoths to build their settlement and to ivory sculptures. Did prehistoric people collect this precious raw material from carcasses -- easy to spot on the big cold steppe -- or were they the direct result of hunting for food? This year-round settlement also yielded a large number of canids remains, some of them with characteristics of Palaeolithic dogs. Were these animals used to help hunt mammoths?

To answer these two questions, Tübingen researcher Hervé Bocherens and his international team carried out an analysis of carbon and nitrogen stable isotopes in human and animal fossil bones from the site. Working with researchers from Brno and Brussels, the researchers were able to test whether the Gravettian people of Předmostí ate mammoth meat and how the "palaeolithic dogs" fit into this subsistence picture.

They found that humans did consume mammoth -- and in large quantities. Other carnivores, such as brown bears, wolves and wolverines, also had access to mammoth meat, indicating the high availability of fresh mammoth carcasses, most likely left behind by human hunters. Surprisingly, the dogs did not show a high level of mammoth consumption, but rather consumed essentially reindeer meat that was not the staple food of their owners. A similar situation is observed in traditional populations from northern regions, who often feed their dogs with the food that they do not like. These results also suggest that these early dogs were restrained, and were probably used as transportation helpers.

These new results provide clear evidence that mammoth was a key component of prehistoric life in Europe 30,000 years ago, and that dogs were already there to help.

Source: Universitaet Tübingen

Emergence of modern sea ice in Arctic Ocean, 2.6 million years ago

Field Work in the Arctic sea ice. Credit: Thomas A. Brown and Simon T. Belt

"We have not seen an ice free period in the Arctic Ocean for 2,6 million years. However, we may see it in our lifetime." says marine geologist Jochen Knies. In an international collaborative project, Knies has studied the historic emergence of the ice in the Arctic Ocean. The results are published in Nature Communications.

The extent of sea ice cover in Arctic was much less than it is today between four and five million years ago. The maximum winter extent did not reaching its current location until around 2.6 million years ago. This new knowledge can now be used to improve future climate models.

"We have not seen an ice free period in the Arctic Ocean for 2,6 million years. However, we may see it in our lifetime. The new IPCC report shows that the expanse of the Arctic ice cover has been quickly shrinking since the 70-ies, with 2012 being the year of the sea ice minimum," Jochen Knies.

He is marine geologist at the Geological Survey of Norway (NGU) and Centre for Arctic Gas Hydrate, Climate and Environment, UiT The Arctic Univeristy of Norway.

In an international collaborative project, Jochen Knies has studied the trend in the sea ice extent in the Arctic Ocean from 5.3 to 2.6 million years ago. That was the last time Earth experienced a long period with a climate that, on average, was warm before cold ice ages began to alternate with mild interglacials.

Fossils reveal past sea ice extent

"When we studied molecules from certain plant fossils preserved in sediments at the bottom of the ocean, we found that large expanses of the Arctic Ocean were free of sea ice until four million years ago," Knies tells us.

"Later, the sea ice gradually expanded from the very high Arctic before reaching, for the first time, what we now see as the boundary of the winter ice around 2.6 million years ago ," says Jochen Knies, who is also attached to CAGE, the Centre for Arctic Gas Hydrate, 

Environment and Climate at the University of Tromsø, the Arctic University of Norway.

Arctic Ocean likely to be completely free of sea ice

The research is of great interest on the international stage because present-day global warming is strongly tied to a shrinking ice cover in the Arctic Ocean. By the end of the present century, the Arctic Ocean seems likely to be completely free of sea ice, especially in summer.

This may have major significance for the entire planet 's climate system. Polar oceans , their temperature and salinity, are important drivers for world ocean circulation that distributes heat in the oceans. It also affects the heat distribution in the atmosphere. Trying to anticipate future changes in this finely tuned system, is a priority for climate researchers. For that they use climate modeling , which relies on good data.

"Our results can be used as a tool in climate modelling to show us what kind of climate we can expect at the turn of the next century. There is no doubt that this will be one of many tools the UN Climate Panel will make use of, too. The extent of the ice in the Arctic has always been very uncertain but, through this work, we show how the sea ice in the Arctic Ocean developed before all the land-based ice masses in the Northern Hemisphere were established," Jochen Knies explains.

Seabed samples from Spitsbergen

A deep well into the ocean floor northwest of Spitsbergen was the basis for this research. It was drilled as part of the International Ocean Drilling Programme, (IODP), to determine the age of the ocean-floor sediments in the area. Then, by analysing the sediments for chemical fossils made by certain microscopic plants that live in sea ice and the surrounding oceans, Knies and his co-workers were able to fingerprint the environmental conditions as they changed through time.

"One thing these layers of sediment enable us to do is to "read" when the sea ice reached that precise point," Jochen Knies tells us.

The scientists believe that the growth of sea ice until 2.6 million years ago was partly due to the considerable exhumation of the land masses in the circum-Arctic that occurred during this period. "Significant changes in altitudes above sea level in several parts of the Arctic, including Svalbard and Greenland, with build-up of ice on land, stimulated the distribution of the sea ice," Jochen Knies says.

"In addition, the opening of the Bering Strait between America and Russia and the closure of the Panama Cannel in central America at the same time resulted in a huge supply of fresh water to the Arctic, which also led to the formation of more sea ice in the Arctic Ocean," Jochen Knies adds.

All the large ice sheets in the Northern Hemisphere existed around 2.6 million years ago.

Scientists at Norwegian Geological Survey (NGU), CAGE, UiT The Arctic University of Norway,University of Plymouth, Universitat Autònoma de Barcelona, Stellenbosch University in South Africa and Institució Catalana de Recerca i Estudis Avançats in Barcelona have collaborated in this work.

Source:  University of Tromso (Universitetet i Tromsø - UiT)

Ancient creature discovered in the depths of the Arctic Ocean

This image shows the new species of bivalve mollusk was recently described and named Wallerconcha sarae. Credit: Paul Valentich-Scott; CC-BY 4.0

In the depths of the Arctic Ocean, buried deep in the sediment, an ancient creature waited for over a million years to be discovered. Paul Valentich-Scott, from the Santa Barbara Museum of Natural History (California), and three scientists from the United States Geological Survey (USGS, Menlo Park, California), Charles L. Powell, Brian D. Edwards, and Thomas D. Lorenson were up to the challenge. Each with different expertise, they were able to collect, analyze, and identify a new genus and new species of bivalve mollusk.

The path to discovery is seldom simple or easy. This discovery is no exception. Brian Edwards was the chief scientist on a joint US-Canadian ice breaker expedition aboard the US Coast Guard Cutter Healy in the summer of 2010. The primary purpose of the expedition was to map the Arctic seafloor and the sediments beneath. Dr. Edwards took deep sediment core samples to further understand the geology of the region including the unusual seafloor mound where these samples were collected. In several of these cores he uncovered bivalve seashells buried nearly 15 feet (4.5 m) below the seafloor surface.

Upon returning to his USGS laboratory in Menlo Park, California, Brian worked with Tom Lorenson on sampling the cores and extracting the shells. The recovered shells were then taken to USGS paleontologist Chuck Powell, for identification. While Chuck was able to ascertain the higher level classification of the clam shells (Family Thyasiridae), he was unable to determine the genus or species. Chuck contacted Paul Valentich-Scott, a clam specialist from the Santa Barbara Museum of Natural History in California.

When examining these ancient shell specimens, Paul was fairly certain that they were new to science. The hunt to validate the potential new species was on. Paul contacted a number of thyasirid bivalve specialists around the world and all gave it a thumbs up as a new species. Further, several scientists felt it also might be a new genus (the level above species).

'It is always exciting when you are the first person to be looking at a new creature' declared Valentich-Scott. 'While I have been fortunate to discover and describe many new species in my career, it is always exhilarating at the outset.'

Then the painstaking work began. Paul contacted museums around the globe and requested to borrow specimens that were potentially related to the new species. While he found many species that shared some characteristics, none matched the new Arctic specimens.

The four scientists have been writing up their findings for the past two years and now the work has been published in the international science journal ZooKeys.

The new genus and species is named after two individuals. The genus is named in honor of Dr. Thomas R. Waller a prominent paleontologist at the Smithsonian Institution. The suffix "concha" meaning shell, is combined to create the name Wallerconcha. The new species is named after Sara Powell the daughter of co-author Chuck Powell. Chuck was quick to mention "I want to name new species after all of my children."

While many of the specimens collected were definitely fossils, the scientists can't discount the new animal might still be alive today. One of the team members, Tom Lorenson, summarized it this way 'The likely collection of living specimens of this species awaits expeditions to come.' Who knows what other new creatures might be found in those expeditions?

Soure: Pensoft Publishers

Laser from a plane discovers Roman goldmines in Spain

These are ancient goldmines in the Eria river valley, with channels and reservoirs for exploitation. The model generated with LiDAR data (left) allows these structures to be located on aerial photos (right). Credit: J. Fernández Lozano et al.

Hidden under the vegetation and crops of the Eria Valley, in León (Spain), there is a gold mining network created by the Romans two thousand years ago, as well as complex hydraulic works, such as river diversions, to divert water to the mines of the precious metal. Researchers from the University of Salamanca made the discovery from the air with an airborne laser teledetection system.

Las Médulas in León is considered to be the largest opencast goldmine of the Roman Empire, but the search for this metal extended many kilometres further south-east to the Erica river valley. Thanks to a Light Detection and Ranging (LiDAR) laser system attached to an aircraft, the ancient mining works of the area and the complex hydraulics system used by the Romans in the 1st century BC to extract gold (including channels, reservoirs and a double river diversion) have been discovered.

"The volume of earth exploited is much greater than previously thought and the works performed are impressive, having achieved actual river captures, which makes this valley extremely important in the context of Roman mining in the north-east of the Iberian Peninsula," as Javier Fernández Lozano, geologist at the University of Salamanca and co-author of this study published in the Journal of Archaeological Science, said.

The specialists consider that the systems for the transport and storage of water were copied from those already existing in North Africa, where the Egyptians had been employing them for centuries. Some details of the methodology used appear in texts such as those of the Pliny the Elder, the Roman procurator in charge of overseeing mining in Hispania.

"We have established that the labour that went into extracting the resource until its exhaustion was so intensive that after removing the gold from surface sediments, operations continued until reaching the rocks with the auriferous quartz veins underneath," explains Fernández Lozano.

The researcher stresses that the real discoverer was the LiDAR technology: "Unlike traditional aerial photography, this airborne laser detection system allows the visualisation of archaeological remains under vegetation cover or intensely ploughed areas."

From aircraft or drones
LiDAR comprises a laser sensor which scans the ground from an aircraft or drone with geographical references provided by GPS ground stations. The data obtained is represented by point clouds, which are processed with a piece of software to construct a cartographic model where the forms are identified, such as old reservoirs or channels.

This technology was developed by NASA in the sixties to analyse the retreating sea ice in the Arctic and composition of the oceans. Since then their use has been extended to topography, cadastral mapping, geology and archaeology. According to the authors, the study of Roman mining in the Eria valley is the first piece of 'geo-archaeology' performed with LiDAR in Spain.

"Our intention is to continue working with this technique to learn more about mineral mining in the Roman Empire and clear up any mysteries such as why Rome abandoned such a precious resource as gold from one day to the next," concludes the researcher.

Source: Plataforma SINC