This research presents an invaluable blueprint for evaluating the significance of human impact on near-time megafauna extinctions. 'So humans - a highly adaptable, social predator - could have landed the final blow.' Our research shows modern humans settled on each landmass after proboscideans had started becoming extinct. 'However, this isn't to say we conclusively disproved any human involvement. This contradicts the claims that early humans started wiping out prehistoric elephants. It seems the broad global pattern of proboscidean extinction could be reproduced without considering the impacts of early human migration. Steven explains, 'The finding is something we didn't anticipate. The team's analysis shows the final proboscidean extinction peaked much earlier, however, at around 2.4 million years ago. Whether humans or climate change caused the extinction of large animals, including proboscideans, is still up for debate today.Įarly humans became effective hunters of large animals around 1.5 million years ago. Was the extinction of proboscideans due to humans or climate change? The most extreme example would be the wooly mammoth, which had thick, shaggy hair and large tusks for retrieving vegetation hidden under thick snow. Only the most ecologically versatile proboscideans survived. This richness of giant herbivores was unlike anything in today's ecosystems.īut from about six million years ago, the diversity in proboscideans started to decrease following the harsh cooling of Earth. This resulted in a variety of forms, with three to four different proboscidean species coexisting in one space. Provided with new challenges and habitats, proboscideans that expanded from their range in Africa evolved 25 times faster than the cousins they left behind. Over the past 20 million years, the global climate changed frequently and dramatically. This was via the land bridge which sporadically connected Siberia to Alaska and is now submerged under the Bering Sea. Once the Afro-Arabian Plate collided into the vast Eurasian landmass, an important migratory corridor was formed, which allowed the species to explore new habitats in Eurasia and then into North America. How and why did proboscideans evolve so rapidly?Įarly proboscideans that lived in Africa were slow-evolving with little diversification. The research culminated into the most detailed analysis to date of the rise and fall of elephants and their cousins. Steven says, 'Some of the most significant clues for gauging the epic proboscidean story were found right here in the collections of the Natural History Museum, one of the very few institutions in the world housing fossil specimens representative of all eight evolutionary directions.' Using fossil collections from museums around the world, they studied the evolutionary adaptations of 185 species over 60 million years of existence. Steven, along with an international team of paleobiologists explored why and how proboscideans changed so much over millions of years. They all bore little resemblance to elephants.' A few species got as big as a hippo, yet these lineages were evolutionary dead ends. 'Most proboscideans over this time were nondescript herbivores ranging from the size of a pug to that of a boar. Steven Zhang, Honorary Research Associate at the University of Bristol, says, 'Remarkably, only two groups of proboscideans evolved during the first half of the proboscidean evolution, which lasted around 30 million years. In fact, some of the earlier species, such as the Eritherium which lived in Morocco, were as small as foxes and lacked a trunk. Unlike the three endangered species of elephants we know today, not all proboscideans were giants, nor did they look anything like their cousins. Proboscideans were a diverse and widespread group of herbivores that first appeared in Africa about 60 million years ago. Elephants - the largest land animals alive today - are the only remaining species of the family Elephantidae, which belongs to an ancient order of Proboscidea.
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