What is the cause of megafauna extinction? What role did we\u2014humans\u2014play in the decline of biodiversity in the supersized animal kingdom?<\/p>\n\n\n\n
The causes of megafauna extinction have puzzled scientists dating back to Cuvier\u2019s day, when the fossils of huge unknown creatures began turning up. Researchers have debated whether megafauna disappeared due to climate change or was killed by humans. But most scientists today lean toward blaming humans.<\/p>\n\n\n\n
Keep reading to learn about megafauna extinction: which species have gone extinct, and what were the causes.<\/p>\n\n\n\n\n\n\n\n
A great variety of supersized animals\u2014megafauna\u2014once stalked the earth. Near the end of the Cretaceous period, there were many groups of huge dinosaurs besides Tyrannosaurus<\/em>. Members of the Saltasaurus<\/em> group weighed around seven tons. A member of the Therizinosaurus<\/em> group was thirty feet long,<\/p>\n\n\n\n Near the end of the last ice age, there were enormous animals all over the world. In Europe, the roster included woolly rhinos, cave bears, giant elk, and hyenas. North America had mastodons, mammoths, giant camels, grizzly-size beavers, saber-toothed cats, and a giant ground sloth. South America had glyptodonts<\/em>, which resembled armadillos the size of small cars. Australia\u2019s even weirder animals included diprotodons<\/em>, a group of huge marsupials called rhinoceros wombats; a marsupial lion, and a ten-foot-tall kangaroo. New Zealand had giant birds\u2014the South Island giant moa was twelve feet tall.<\/p>\n\n\n\n Interestingly, megafauna extinction in Australia and the Americas coincided with the appearance of humans. There\u2019s also evidence that Maori killed off the giant birds in New Zealand: the remains of outdoor ovens and \u201cmiddens\u201d containing bones of large birds.<\/p>\n\n\n\n The advantage of being too big to have predators disappeared when humans came on the scene. At that point, the flipside of being extra-large\u2014being slow to reproduce\u2014became a disadvantage.<\/strong> If humans killed off large numbers of a species\u2014or even killed small numbers continually for millennia\u2014the rest wouldn\u2019t have been able to reproduce fast enough to avoid extinction.<\/p>\n\n\n\n Human pressure plus slow reproduction are also why big animals like elephants, bears, and rhinos are in trouble today. Take rhinos, for example. Humans have killed so many rhinos and destroyed so much of their habitat that, ironically, only extraordinary human efforts can save them.<\/p>\n\n\n\n The double-horned Sumatran rhino is the smallest and oldest of the five species of rhino that still exist. It once ranged from the foothills of the Himalayas through Myanmar, Thailand, Cambodia, and beyond. But by the early 1980s, its population had shrunk to a few hundred and was heading toward extinction due to habitat loss as southeast Asia\u2019s forests were cut down.<\/p>\n\n\n\n Other rhino species are also at risk including Javan rhinos, Indian rhinos, black rhinos, white rhinos, to name a few.<\/p>\n\n\n\n In fact, almost all large mammals are in trouble:<\/p>\n\n\n\n What is the cause of megafauna extinction? What role did we\u2014humans\u2014play in the decline of biodiversity in the supersized animal kingdom? The causes of megafauna extinction have puzzled scientists dating back to Cuvier\u2019s day, when the fossils of huge unknown creatures began turning up. Researchers have debated whether megafauna disappeared due to climate change or was killed by humans. But most scientists today lean toward blaming humans. Keep reading to learn about megafauna extinction: which species have gone extinct, and what were the causes.<\/p>\n","protected":false},"author":7,"featured_media":25795,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[39,160],"tags":[201],"class_list":["post-25794","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-history","category-science","tag-the-sixth-extinction","","tg-column-two"],"yoast_head":"\nBig Animals in Trouble Today<\/strong><\/h3>\n\n\n\n