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Tag: University of the Witwatersrand

  • Africans discovered fossils first

    Africans discovered fossils first

    Newswise — Credit for discovering the first dinosaur bones usually goes to British gentlemen for their finds between the 17th and 19th centuries in England. Robert Plot, an English natural history scholar, was the first of these to describe a dinosaur bone, in his 1676 book The Natural History of Oxfordshire. Over the next two centuries dinosaur palaeontology would be dominated by numerous British natural scientists.

    But our study shows that the history of palaeontology can be traced back much further into the past. We present evidence that the first dinosaur bone may have been discovered in Africa as early as 500 years before Plot’s.

    We’re a team of scientists who study fossils in South Africa. Peering through the published and unpublished archaeological, historical and palaeontological literature, we discovered that there has been interest in fossils in Africa for as long as there have been people on the continent.

    This is not a surprise. Humankind originated in Africa: Homo sapiens has existed for at least 300,000 years. And the continent has a great diversity of rock outcrops, such as the Kem Kem beds in Morocco, the Fayum depression in Egypt, the Rift Valley in east Africa and the Karoo in southern Africa, containing fossils that have always been accessible to our ancestors.

    So it wasn’t just likely that African people discovered fossils first. It was inevitable.

    More often than not, the first dinosaur fossils supposedly discovered by scientists were actually brought to their attention by local guides. Examples are the discovery of the gigantic dinosaurs Jobaria by the Tuaregs in Niger and Giraffatitan by the Mwera in Tanzania.

    Our paper reviews what’s known about African indigenous knowledge of fossils. We list fossils that appear to have long been known at various African sites, and discuss how they might have been used and interpreted by African communities before the science of palaeontology came to be.

    Bolahla rock shelter in Lesotho

    One of the highlights of our paper is the archaeological site of Bolahla, a Later Stone Age rock shelter in Lesotho. Various dating techniques indicate that the site was occupied by the Khoesan and Basotho people from the 12th to 18th centuries (1100 to 1700 AD). The shelter itself is surrounded by hills made of consolidated sediments that were deposited under a harsh Sahara-like desert some 180 million to 200 million years ago, when the first dinosaurs roamed the Earth.

    This part of Lesotho is particularly well known for delivering the species Massospondylus carinatus, a 4 to 6 metre, long-necked and small-headed dinosaur. Fossilised bones of Massospondylus are abundant in the area and were already so when the site was occupied by people in the Middle Ages.

    In 1990, archaeologists working at Bolahla discovered that a finger bone of Massospondylus, a fossil phalanx, had been transported to the cave. There are no fossil skeletons sticking out the walls of the cave, so the only chance that this phalanx ended up there was that someone in the distant past picked it up and carried it to the cave. Perhaps this person did so out of simple curiosity, or to turn it into a pendant or toy, or to use it for traditional healing rituals.

    After heavy rains, it is not unusual that the people in the area discover the bones of extinct species that have been washed out of their mother-rock. They usually identify them as belonging to a dragon-like monster that devours people or even whole houses. In Lesotho, the Basotho call the monster “Kholumolumo”, while in South Africa’s bordering Eastern Cape province, the Xhosa refer to it as “Amagongqongqo”.

    The exact date when the phalanx was collected and transported is unfortunately lost to time. Given the current knowledge, it could have been at any time of occupation of the shelter from the 12th to 18th centuries. This leaves open the possibility that this dinosaur bone could have been collected up to 500 years prior to Robert Plot’s find.

    Early knowledge of extinct creatures

    Most people knew about fossils well before the scientific era, for as far back as collective societal memories can go. In Algeria, for example, people referred to some dinosaur footprints as belonging to the legendary “Roc bird”. In North America, cave paintings depicting dinosaur footprints were painted by the Anasazi people between AD 1000 and 1200. Indigenous Australians identified dinosaur footprints as belonging to a legendary “Emu-man”. To the south, the notorious conquistador Hernan Cortes was given the fossil femur of a Mastodon by the Aztecs in 1519. In Asia, Hindu people refer to ammonites (coiled fossil-sea-shells) as “Shaligrams” and have been worshipping them for more than 2,000 years.

    Claiming credit

    The fact that people in Africa have long known about fossils is evident from folklore and the archaeological record, but we still have much to learn about it. For instance, unlike the people in Europe, the Americas and Asia, indigenous African palaeontologists seem to have seldom used fossils for traditional medicine. We are still unsure whether this is a genuinely unique cultural trait shared by most African cultures or if it is due to our admittedly still incomplete knowledge.

    Also, some rather prominent fossil sites, such as the Moroccan Kem Kem beds and South African Unesco Cradle of Humankind caves, have still not provided robust evidence for indigenous knowledge. This is unfortunate, as fossil-related traditions could help bridge the gap between local communities and palaeontologists, which in turn could contribute preserving important heritage sites.

    By exploring indigenous palaeontology in Africa, our team is putting together pieces of a forgotten past that gives credit back to local communities. We hope it will inspire a new generation of local palaeoscientists to walk in the footsteps of these first African fossil hunters.

    University of the Witwatersrand, Johannesburg

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  • New study shows signs of early creation of modern human identities

    New study shows signs of early creation of modern human identities

    BYLINE: Wits University

    Newswise — A new study confirms previous scant evidence and supports a multistep evolutionary scenario for the culturalization of the human body.

    The new study, which was conducted by Francesco d’Errico, Karen Loise van Niekerk, Lila Geis and Christopher Stuart Henshilwood, from Bergen University in Norway and the University of the Witwatersrand (Wits) in Johannesburg, South Africa, is newly published in the Journal of Human Evolution. Its significant findings provide vital information about how and when we may have started developing modern human identities.

    “The discovery of eye-catching unmodified shells with natural holes from 100 to 73 years ago confirms previous scant evidence that marine shells were collected, taken to the site and, in some cases, perhaps worn as personal ornaments. This was before a stage in which shells belonging to selected species were systematically, and intentionally perforated with suitable techniques to create composite beadworks,” says van Niekerk.

    The shells were all found in the Blombos Cave, on the southern Cape of South Africa’s coastline. Similar shells have been found in North Africa, other sites in South Africa and the Mediterranean Levant, which means that the argument is supported by evidence from other sites, not just Blombos Cave.

    Confirms scant evidence of early beadwork

    In other words, the unperforated and naturally perforated shells provide evidence that marine shells were collected and possibly used as personal ornaments before the development of more advanced techniques to modify the shells for use in beadworks at around 70 years ago.

    Van Niekerk says that they know for sure that these shells are not the remains of edible shellfish species that could have been collected and brought to the site for food.

    “We know this because they were already dead when collected, which we can see from the condition of most of the shells, as they are waterworn or have growths inside them, or have holes made by a natural predator or from abrasion from wave action.”

    The researchers measured the size of the shells and the holes made in them, as well as the wear on the edges of the holes that developed while the shells were worn on strings by humans. They also looked at where the shells came from in the site to see whether they could be included in different groups of beads found close together that could have belonged to single items of beadwork. These techniques provide insights into the potential use of these shells for symbolic purposes.

    Early signs of possibly creation of identity

    Van Niekerk says that they identified 18 new marine snail shells from 100 to 70 years ago, that could have been used for symbolic purposes, and proposed a multistep progression for the culturalisation of the human body with roots in the deep past.

    “With this study we specifically show that humans gradually complexified practices of modifying their appearance and transformed themselves into tools for communication and storage of information. We also think we can possibly see a creation of identity that gradually but radically changed the way we look at ourselves and others, and the nature of our societies,” says van Niekerk.

    University of the Witwatersrand, Johannesburg

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  • Noise-free comms via structured light, say researchers

    Noise-free comms via structured light, say researchers

    Newswise — The patterns of light hold tremendous promise for a large encoding alphabet in optical communications, but progress is hindered by their susceptibility to distortion, such as in atmospheric turbulence or in bent optical fibre.  Now researchers at the University of the Witwatersrand (Wits) have outlined a new optical communication protocol that exploits spatial patterns of light for multi-dimensional encoding in a manner that does not require the patterns to be recognised, thus overcoming the prior limitation of modal distortion in noisy channels.  The result is a new encoding state-of-the-art of over 50 vectorial patterns of light sent virtually noise-free across a turbulent atmosphere, opening a new approach to high-bit-rate optical communication.  

    Published this week in Laser & Photonics Reviews, the Wits team from the Structured Light Laboratory in the Wits School of Physics used a new invariant property of vectorial light to encode information.  This quantity, which the team call “vectorness”, scales from 0 to 1 and remains unchanged when passing through a noisy channel.  Unlike traditional amplitude modulation which is 0 or 1 (only a two-letter alphabet), the team used the invariance to partition the 0 to 1 vectorness range into more than 50 parts (0, 0.02, 0.04 and so on up to 1) for a 50-letter alphabet.  Because the channel over which the information is sent does not distort the vectorness, both sender and received will always agree on the value, hence noise-free information transfer.  

    The critical hurdle that the team overcame is to use patterns of light in a manner that does not require them to be “recognised”, so that the natural distortion of noisy channels can be ignored.  Instead, the invariant quantity just “adds up” light in specialised measurements, revealing a quantity that doesn’t see the distortion at all.

    “This is a very exciting advance because we can finally exploit the many patterns of light as an encoding alphabet without worrying about how noisy the channel is,” says Professor Andrew Forbes, from the Wits School of Physics. “In fact, the only limit to how big the alphabet can be is how good the detectors are and not at all influenced by the noise of the channel.”

    Lead author and PhD candidate Keshaan Singh adds: “To create and detect the vectorness modulation requires nothing more than conventional communications technology, allowing our modal (pattern) based protocol to be deployed immediately in real-world settings.”

    The team have already started demonstrations in optical fibre and in fast links across free-space, and believe that the approach can work in other noisy channels, including underwater.

    University of the Witwatersrand

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