Turkana whale fossil that has baffled renowned scientists
Researchers continue to rack their brains over the find of a whale fossil inland, raising enquiries into the link between the north and the Indian Ocean.
By Daily Nation
In 1964, a team from Harvard University-Kenya Expedition found an intriguing find in West Turkana: a 17-million-year-old whale fossil. How this open ocean whale reached Turkana, some 1,200 kilometres from the Indian Ocean, still interests researchers eager to unravel the behaviour of the Rift Valley Lakes.
What they know is that there was a river with “sufficient discharge and connectivity with the open ocean to provide an unrestricted pathway for the upstream migration of the whale.”
Next year, a team of researchers from Stony Brook University will be returning to Kenya to answer the question: Why was this whale in Turkana – and how did it reach there?
The answer to that question, they say, will help us understand how climate change and the shifts in the Rift Valley tectonics, especially during the Miocene period, which ranges from 23 million to 5.3 million years ago, affected life and evolution of mammals in the region.
Discovered by a Yale University undergraduate student James G. Mead, this is the only beaked whale fossil discovered inland. But, for more than 30 years after the publication of Mead’s finding in 1975, the skull went missing.
For years, it was believed to have been mixed up at the National Museums Department of Palaeontology stores and Dr Mead, at one time the head of that division, continued to search for the skull with little success.
It was not until 2011, at the tail-end of his research career, that Dr Mead finally traced the skull at Harvard University and had it returned to the National Museums of Kenya, where it is housed and catalogued as KNM-LP 52956.
It is only by luck that this fossil, originally thought to be a turtle, was traced.
This is how it disappeared. Shortly after James Mead first identified the specimen in the field as a large turtle, he borrowed the specimen while he was undertaking graduate studies at the University of Texas, and PhD from the University of Chicago, from the Expedition leader Prof Bryan Patterson. He then returned it to Harvard in the late 1960s and had a paper published in 1975. But Prof Patterson, in whose custody the specimen was, died and nobody knew where he had kept it.
In 1980s, when Mead was the Head of Paleontology at the Kenya National Museums (KNM), he started a search for this whale skeleton at the Museum of Comparative Zoology, Harvard, the Smithsonian Institution, and the KNM together with other scientists, Dr Meave Leakey, L. J. Flynn, Richard Leakey and A. K. Behrensmeyer.
It was in 2011 that a Harvard collection manager Jessica Cundiff located the Turkana ziphiid in what had been the office of the renowned paleontologist Stephen Jay Gould and it was repatriated to Kenya. Luckily, Dr Mead, a vertebrate palaeontologist, had described his findings in a scientific journal and continued to work on marine mammals with a PhD on the anatomy of the dolphin head.
Mead’s discovery of the Turkana whale led to the confirmation of the existence of the ancient Anza River, which flowed from Ethipia to modernday Turkana into the Indian Ocean through what geologists call the Anza Trough – a rift-like valley that had been formed during the Jurassic period, mainly characterised by dinosaurs.
Researchers have found dinosaur bones on the southern tip of Lake Turkana, where bones of extinct ancient crocodiles and large aquatic lizards, first discovered in a limestone quarry at Maastricht, Netherlands, in 1764, have been found. It is in this Anza basin, which stretches towards Mandera and runs to Lamu, that energy companies such as Tullow Oil have been scouting for hydrocarbons, especially within the four large sedimentary basins.
Another question that scientists have been asking is why this whale was trapped inland and the climate conditions of that period. Since this skeleton was discovered in a former river bed and among some molluscs associated with swampy areas, palaeontologists suspect that it was preserved near where it died.
Five years ago, a team from Southern Methodist University, Texas, the National Museums of Kenya and the University of Potsdam, Germany, began a study on this beaked whale and were able to pinpoint a date when this whale swam north in a low-gradient river with no waterfalls.
“The whale was stranded up river at a time when East Africa was at sea level and was covered with forest and jungle,” Prof Louis Jacobs of Southern Methodist University, a co-author of the paper published in the Proceedings of the National Academy of Sciences, was quoted as saying.
As the oldest known beaked whale, the Turkana fossil is offering insights into how parts of the continent tilted, or rather rose up, a phenomenon that made the climate become drier, as forests that covered parts of modernday northern and eastern Kenya were turned into grasslands.
Some of these ancient forests are today preserved in Sibiloi National Park, where logs of petrified cedar trees dating more than 7 million years ago were discovered in 1970s. This is evidence that a huge forest covered this area before climate change turned it into grassland – and later on a near-desert.
It was also the reason that we have evidence of early man in the same region, as some primates evolved to adapt to the new environment and finally stopped the knuckle walking (as baboons do) and walked straight.
It is this curiosity that makes Turkana the cradle of mankind since the basin has preserved most of the evidence in place and which has seen enormous research in the Koobi Fora region, which is these days led by Prof Jack Harris – the Rutgers University professor who has trained more archaeologists to help unravel the mystery of the Anza basin through the Koobi Fora Field School. Prof Harris has dedicated his life and scholarship in the Turkana basin and is a common feature at the National Museums of Kenya.
In western Turkana is another team, the Turkana Basin Institute, which hunts for fossils and attempts to understand human and climatic shifts that took place here millions of years ago.
It is this team led by Stony Brook University scholar Isaiah Odhiambo Nengo that will next year return to look again at the Turkana whale and shed light on “how climate change and tectonics on Miocene ecosystems in this region influenced life and evolution, from the whale to now.”
Known as the Turkana Miocene Project, the four-year project is supported by a $2.7 million (Sh292 million) grant from the National Science Foundation’s Frontier Research in Earth Sciences Programme and will involve Named the Turkana Miocene Project, the research is multinational, interdisciplinary and involve five core US universities.
“The goal is to better define through fieldwork, laboratory analysis and climate modeling how tectonics and climate interacted to shape the environment that gave rise to the ancestors of humans and our closest living relatives, the chimpanzees, gorillas, and orangs that emerged in Africa,” a statement about this project said in part.
This research is coming at a time when Kenyans are witnessing various changes in the Rift Valley lakes, which have started rising. There is still no clear geologic explanation on why the lakes have started rising, marooning human settlements on the previous shores.As Prof Nengo says, “the East African Rift is among the best places to study the influences of Earth processes on the evolution of mammals. Here, uniquely, the region’s geologic and climate histories, including the formation of the rift system that is the cradle of humankind, are preserved in sedimentary rocks. Our collaborative work will tease out how tectonics and climate come together to drive evolution.”
Back to the Turkana whale. Palaeontologists have identified it as a Turkana ziphiid, and that, like its modern beaked cousins, it was one of the ocean’s top predators.
Zoologists say that ziphiids are the deepest diving air-breathing mammals alive, and can plunge to depths of nearly 10,000 feet to feed, primarily on squid. Prof Louis Jacobs of Southern Methodist University, a scientist who has studied this Turkana whale environment has been quoted saying: “You don’t usually find whales so far inland.Many of the known beaked whale fossils are dredged by fishermen from the bottom of the sea.”
It is in answering most of these questions that Kenyans will start appreciating the rich history that lies in our neglected north and how it could be of interest to many researchers and tourists – but only if we can open this region.
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