Scientists reconstruct extinct species using fossils found in northern Mali from ancient seaway
Some of the biggest catfish and sea snakes to ever exist lived in what is today the Sahara desert, according to a new paper that contains the first reconstructions of extinct aquatic species from the ancient Trans-Saharan Seaway.
The sea was 50 metres deep and once covered 3,000 sq-km of what is now the world’s biggest sand desert. The marine sediment it left behind is filled with fossils, which allowed the scientists who published the study to build up a picture of a region that teemed with life.
Between 100 million and 50 million years ago, today’s arid, boulder-strewn northern Mali “looked more like modern Puerto Rico”; the sun shone on some of the earliest mangroves, and molluscs lined the shallow seabed, according The Guardian, citing Maureen O’Leary, the palaeontologist who led the study.
The study also formally named the geological units, literally putting the area on the geological map for the first time, showing how the sea ebbed and flowed over its 50 million years of existence, and building up information about the K-Pg boundary, the geophysical marker of one of Earth’s five major extinction events, in which the non-avian dinosaurs became extinct.
Though considerably less watery and verdant today, there is no shortage of human life in the Sahara – people for whom the presence of ancient sea creatures is not news, as the team found during their expeditions in 1999, 2003 and 2009.
“The Sahara is full of people. Sometimes we would be working in what seemed like the most remote desert, and someone would just drive up on a moped. It’s a very alive environment,” said O’Leary, who is from Stony Brook University in the US. “The local people … knew that the sea had passed, and they would talk about the shells that they found and know that they’re marine shells.”