Campo Laborde Pampas megafauna extinction giant ground sloth

Evidence for human involvement in extinction of megafauna in the late Pleistocene

Evidence for human involvement in extinction of megafauna in the late Pleistocene

Campo Laborde: A Late Pleistocene giant ground sloth kill and butchering site in the Pampas

Campo Laborde Pampas megafauna extinction giant ground sloth
Lithic tool associated with giant ground sloth bones. Credit: Gustavo Politis and Pablo Messineo

By re-dating giant ground sloth remains found in the Argentinian Pampas region using more advanced technology, scientists say they have provided evidence that humans hunted and butchered this animal near a swamp during the end of the Pleistocene. Based on their radiocarbon dates of this specimen, the authors say that their report challenges the popular hypothesis that megamammals from South America survived well into the Holocene in the Pampas, instead suggesting they took their last breaths in the Pleistocene. Loss of up to 90% of large animal species on ice-free continents occurred during the end of the Pleistocene, and many megafauna went extinct. To date, studies have suggested that humans and/or climate-driven events could be to blame for megafauna loss, but the causes and dynamics of megafauna extinction are hard to determine, and direct evidence of human predation on megafauna is scarce. The Argentinian archeological site Campo Laborde has produced many megafauna fossils, but accurate radiocarbon dating has been difficult on these bones because the fossils have very little collagen, making it hard to extract. Dating is also challenging because the collagen is heavily contaminated with sedimentary organic matter. To overcome this contamination, Gustavo G. Politis and colleagues thought to apply XAD purification chemistry, which can isolate the amino acids in a bone's collagen, resulting in a more accurate radiocarbon date, they say. Only one bone from a giant ground sloth found at Campo Laborde contained collagen. This specimen was first dated in 2007 as being around 9,730 years of age (pegging it to the Holocene, which began around 11,650 years ago). Using accelerator mass spectrometry to radiocarbon date the amino acids of the specimen, Politis determined that the giant ground sloth bone better dated to around 10,570 years of age, plus or minus 170 years. According to the authors, contaminated collagen was the reason for the previous "younger" (Holocene) dates. In addition to the previously discovered lithic artifacts that were found around the giant ground slot and dated to around 11,800 and 10,000 years before present, this study "solidly dates" the killing and exploitation of the giant ground sloth to the late Pleistocene and does not support extinct megamammals surviving into the Holocene at Campo Laborde, the authors say.

Press release by AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE

 


hominins fossils Ardipithecus ramidis Afar Regional State Ethiopia

New findings shed light on origin of upright walking in human ancestors

New findings shed light on origin of upright walking in human ancestors

4.5 million-year old fossil shows evidence of greater reliance on bipedalism than previously suggested

 

The oldest distinguishing feature between humans and our ape cousins is our ability to walk on two legs - a trait known as bipedalism. Among mammals, only humans and our ancestors perform this atypical balancing act. New research led by a Case Western Reserve University School of Medicine professor of anatomy provides evidence for greater reliance on terrestrial bipedalism by a human ancestor than previously suggested in the ancient fossil record.

Scott W. Simpson, PhD, led an analysis of a 4.5 million-year-old fragmentary female skeleton of the human ancestor Ardipithecus ramidus that was discovered in the Gona Project study area in the Afar Regional State of Ethiopia.

The newly analyzed fossils document a greater, but far from perfect, adaptation to bipedalism in the Ar. ramidus ankle and hallux (big toe) than previously recognized. "Our research shows that while Ardipithecus was a lousy biped, she was somewhat better than we thought before," said Simpson.

Fossils of this age are rare and represent a poorly known period of human evolution. By documenting more fully the function of the hip, ankle, and foot in Ardipithecus locomotion, Simpson's analysis helps illuminate current understanding of the timing, context, and anatomical details of ancient upright walking.

Previous studies of other Ardipithecus fossils showed that it was capable of terrestrial bipedalism as well as being able to clamber in trees, but lacked the anatomical specializations seen in the Gona fossil examined by Simpson. The new analysis, published in the Journal of Human Evolution, thus points to a diversity of adaptations during the transition to how modern humans walk today. "The fact that Ardipithecus could both walk upright, albeit imperfectly, and scurry in trees marks it out as a pivotal transitional figure in our human lineage," said Simpson.

Key to the adaptation of bipedality are changes in the lower limbs. For example, unlike monkeys and apes, the human big toe is parallel with the other toes, allowing the foot to function as a propulsive lever when walking. While Ardipithecus had an offset grasping big toe useful for climbing in trees, Simpson's analysis shows that it also used its big toe to help propel it forward, demonstrating a mixed, transitional adaptation to terrestrial bipedalism.

Specifically, Simpson looked at the area of the joints between the arch of the foot and the big toe, enabling him to reconstruct the range of motion of the foot. While joint cartilage no longer remains for the Ardipithecus fossil, the surface of the bone has a characteristic texture which shows that it had once been covered by cartilage. "This evidence for cartilage shows that the big toe was used in a more human-like manner to push off," said Simpson. "It is a foot in transition, one that shows primitive, tree-climbing physical characteristics but one that also features a more human-like use of the foot for upright walking." Additionally, when chimpanzees stand, their knees are "outside" the ankle, i.e., they are bow-legged. When humans stand, the knees are directly above the ankle - which Simpson found was also true for the Ardipithecus fossil.

The Gona Project has conducted continuous field research since 1999. The study area is located in the Afar Depression portion of the eastern Africa rift and its fossil-rich deposits span the last 6.3 million years. Gona is best known as documenting the earliest evidence of the Oldowan stone tool technology. The first Ardipithecus ramidus fossils at Gona were discovered in 1999 and described in the journal Nature in 2005. Gona has also documented one of the earliest known human fossil ancestors - dated to 6.3 million years ago. The Gona Project is co-directed by Sileshi Semaw, PhD, a research scientist with the CENIEH research center in Burgos, Spain, and Michael Rogers, PhD, of Southern Connecticut State University. The geological and contextual research for the current research was led by Naomi Levin, PhD, of the University of Michigan, and Jay Quade, PhD, of the University of Arizona.

hominins fossils bipedalism Ardipithecus ramidis Afar Regional State Ethiopia
This is a fossil hominin talus from site GWM67 (2005) at the time of its discovery. Credits: Case Western Reserve University School of Medicine

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This research was made possible by use of the human and ape skeletal collections housed at the Laboratory of Physical Anthropology, Cleveland Museum of Natural History. Major financial support was provided by the L.S.B. Leakey Foundation, Spain's Ministerio de Economia, Industria y Competitividad, Marie Curie EU Integration Grant, U.S. National Science Foundation, Case Western Reserve University, the National Geographic Society, and the Wenner-Gren Foundation.

Simpson, S., et al. "Ardipithecus ramidus postcrania from the Gona Project area, Afar Regional State, Ethiopia." Journal of Human Evolution. DOI: 10.1016/j.jhevol.2018.12.005

For more information about Case Western Reserve University School of Medicine, please visit case.edu/medicine.

Press release from Case Western Reserve University


clam gardens Quadra Island British Columbia Northwest Coast peoples

Northwest Coast clam gardens nearly 2,000 years older than previously thought

Northwest Coast clam gardens nearly 2,000 years older than previously thought

A study led by SFU archaeology professor Dana Lepofsky and Hakai Institute researcher Nicole Smith reveals that clam gardens, ancient Indigenous food security systems located along B.C.'s coast, date back at least 3,500 years--almost 2,000 years older than previously thought. These human-built beach terraces continue to create habitat for clams and other sea creatures to flourish in the area.

For thousands of years, First Nations of the Northwest Coast, from Alaska to Washington, relied on clams as a staple food. Clam gardens have helped Indigenous peoples prevent the depletion of this important food resource despite ongoing harvesting to support the growth of dense and widespread human populations.

"Oral traditions, songs, and local Indigenous knowledge, as well as the archaeological record indicate that clam gardens were built and used throughout the coast," says Dana Lepofsky. "However, because clam gardens are constructed of rock, it is difficult to determine the age of these features using standard archaeological techniques.

"The findings in this study provide unequivocal evidence for long-term and sustainable management of coastal ecosystems by Northwest Coast peoples -- and supports what they have always said about their traditional marine management practices."

For the study, published in PLOS ONE, the researchers analyzed multiple clam gardens located on Quadra Island, British Columbia. They used radiocarbon dating on the clams and other marine organisms that were trapped when the clam garden walls were built, as well as the accumulating sediment.

The researchers combined this information with the history of changing sea levels in the area to achieve a more accurate read than previous studies.

"This traditional form of mariculture has been used continuously for 3500 years and into the present day, and it holds potential to become a model for how local, sustainable food systems could operate in the future," says Nicole Smith.

clam gardens Quadra Island British Columbia Northwest Coast peoples
A study led by SFU archaeology professor Dana Lepofsky and Hakai Institute researcher Nicole Smith reveals that clam gardens, ancient Indigenous food security systems located along B.C.'s coast, date back at least 3,500 years--almost 2,000 years older than previously thought. These human-built beach terraces continue to create habitat for clams and other sea creatures to flourish in the area. Credits: Nicole Smith

Press release from Simon Fraser University


Foxes were domesticated by humans in the Bronze Age

In the northeast of the Iberian Peninsula, between the third and second millennium BC, a widespread funeral practice consisted in burying humans with animals. Scientists have discovered that both foxes and dogs were domesticated, as their diet was similar to that of their owners.

dogs foxes Can Roqueta Minferri Spain Bronze Age prehistory
Artistic representation of a woman of the Bronze Age accompanied by a dog and a fox / J. A. Peñas

The discovery of four foxes and a large number of dogs at the Can Roqueta (Barcelona) and Minferri (Lleida) sites stands out among the many examples of tombs in different parts of the north-eastern peninsula. These burials reveal a generalized funeral practice that proliferated in the Early to Middle Bronze Age: that of burying humans together with domestic animals.

What is most striking about these sites is the way of burying the dead in large silos, along with their dogs and a few foxes. “We discovered that in some cases the dogs received a special kind of food. We believe this is linked to their function as working dogs. Besides, one of the foxes shows signs of having already been a domestic animal in those times,” Aurora Grandal-d'Anglade, co-author of a study on the relationship between humans and dogs through their diet published in the journal Archaeological and Anthropological Sciences, has said to to Sinc.

By means of studying stable carbon and nitrogen isotopes in bone collagen, as well as archaeological, archaeobiological and anthropological studies, researchers have been able to compare the diets of buried animals with their owners´ diet. A total of 37 dogs, 19 domestic ungulates and 64 humans were analyzed. The results indicate that the dogs’ diet was similar to that of humans.

The isotopic study of the Minferri foxes shows a varied diet: in some cases it looks similar to that of the dogs at that site, and in another it looks more like that of a wild animal or one that had little contact with humans.

“The case of the Can Roqueta fox is very special, because it is an old animal, with a broken leg. The fracture is still in its healing process, and shows signs of having been immobilized (cured) by humans. The feeding of this animal is very unusual, as it is more akin to a puppy dog’s. We interpret it as a domestic animal that lived for a long time with humans,” explains Grandal.

Large dogs used for transporting loads

The study points out that, in some particular cases in Can Roqueta, there was a specific cereal-rich food preparation for larger dogs probably used for carrying loads, and for at least one of the foxes.

“These specimens also show signs of disorders in the spinal column linked to the transport of heavy objects. Humans were probably looking for a high-carbohydrate diet because the animals developed a more active job, which required immediate calorie expenditure. It may seem strange that dogs were basically fed with cereals, but this was already recommended by the first-century Hispano-Roman agronomist Lucius Junius Moderatus Columella , in his work De re rustica”, says Silvia Albizuri Canadell, co-author of the work and archaeozoologist at the University of Barcelona.

Other animals, such as cows, sheep or goats are noted for an herbivorous diet. Their function was probably to provide milk, meat or wool rather than serve as a work force. “The horse was not yet widespread in those societies, no traces of it can be found until later times,” adds the scientist.

In general, humans and dogs show somewhat higher isotopic signals than ungulates, which indicates a certain (not very high) consumption of animal protein, “not necessarily much meat; they could be, for example, derived from milk,” explains Grandal. Archaeological objects included sieves that served as ‘cheese making devices’.

Moreover, men seem to have included more meat than women in their diet. As for dogs, their diet may have been mainly from leftovers of what humans ate, mostly more similar to that of women and children. “That's why we thought they were more linked to these domestic environments,” says the researcher. There are many ethnographic parallels that indicate this relationship between women and dogs.

 

Feeding and treatment of foxes and dogs

The fundamental role of dogs during the Bronze Age, when livestock, along with agriculture, constituted the basis of the economy, was that of the surveillance and guidance of herds. They were also responsible for taking care of human settlements, given the risk posed by the frequent presence of dangerous animals such as wolves or bears.

“The characteristics of dogs include their great intelligence, easy trainability and, undoubtedly, their defensive behaviour. As if that were not enough, this animal was used until the nineteenth century AD in North America, Canada and Europe for light transport on its back and for dragging carts and sleds. It also functioned as a pack animal on the Peninsula during the Bronze Age,” Albizuri Canadell claims.

Some archaeological specimens from North America show bone disorders that stem from the pulling of ‘travois’. There are also accounts by the first colonizers of the use of dogs in these tasks by Indian populations until the nineteenth century AD, although they had not been identified in Europe until a few years ago.

“It was the Can Roqueta specimens under study that triggered the alarm about the use of this animal for light loads since antiquity, and they’re an exceptional case in Europe,” says Albizuri Canadell.

Similar pathologies have also been recently identified in the vertebrae of Siberian Palaeolithic dogs, leading one to think that one of the first tasks since their early domestication was the pulling of sleds and travois, in addition to hunting.

Its role as a transport animal in the first migrations and human movements through glacial Europe could have been fundamental and much more important than believed until recently.

The reason for animal offerings

Exceptional findings, such as those of tomb #88 and #405 of the Minferri site (Lleida), show that during the Bronze Age there were already well-differentiated funeral treatments in human communities.

“In the two structures mentioned above, the remains of three individuals were found together with animal offerings. In tomb #88 there was the body of an old man with the remains of a whole cow and the legs of up to seven goats. Theremains of a young woman with the offering of a whole goat, two foxes and a bovine horn were also found,” states Ariadna Nieto Espinet, an archaeologist from the University of Lleida and also the co-author of the study.

Structure #405 uncovered the body of an individual, possibly a woman, accompanied by the whole bodies of two bovines and two dogs. “We still don't know why only a few people would have had the right or privilege to be buried with this type of offering, unlike what happens with the vast majority of burials,” the expert points out.

In Can Roqueta, clear differences have also been observed in the deposits of domestic animals within the tombs of adults, both men and women, which are even reflected in children's tombs. From this we can infer the existence of an inheritance of social status from birth.

“It is tempting to think that if we understand domestic animals as a very important part of the agro- pastoral agro-shepherding economy of the Bronze Age and of the belongings of some people in life, these could be an indicator of the wealth of the deceased individual  or of his clan or family,” argues Nieto Espinet.

“It seems that species such as bovines and dogs, two of the most recurring animals in funeral offerings, are those that might have played a fundamental role in the economy and work as well as in the symbolic world, becoming elements of ostentation, prestige and protection,” she concludes.

References:

Aurora Grandal-d’Anglade, Silvia Albizuri, Ariadna Nieto, Tona Majó, Bibiana Agustí, Natalia Alonso, Ferran Antolín, Joan B. López, Andreu Moya, Alba Rodríguez y Antoni Palomo. “Dogs and foxes in Early-Middle Bronze Age funerary structures in the northeast of the Iberian Peninsula: human control of canid diet at the sites of Can Roqueta (Barcelona) and Minferri (Lleida)” Archaeological and Anthropological Sciences https://doi.org/10.1007/s12520-019-00781-z

Press release from Agencia Sinc, author Eva Rodriguez