.S. President Donald Trump (C) delivers remarks to military personnel and families at Joint Base Andrews in Maryland air max scontate saldi , the United States, on Sept. 15, 2017. U.S. President Donald Trump on Friday pledged close collaboration with Britain, hours after his tweet on the latest London attack drew pushback from the UK's top leader. (XinhuaYin Bogu)






Special snacks displayed during 14th China-ASEAN Expo


Scenery of paddy fields in Baicheng, NE China's Jilin


China Focus: World's oldest panda dies aged 37


Scenery of terraced fields at Wuyishan in SE China's Fujian


Intangible cultural heritage: Clear Noodles in Chili Sauce


Bird's-eye view of Zibo City in east China


Fire drill held in S China's Guangxi


China, Pakistan air forces hold joint training exercises


WASHINGTON air max scontate italia , July 3 (Xinhua) -- Most of the frogs alive today may owe a "big thank you" to the mass extinction that wiped out dinosaurs 66 million years ago.


A new study by Chinese and American biologists showed that 88 percent of today's frog species have descended from just three lineages that survived the calamity, likely caused by an asteroid or comet striking the Earth.


"Frogs have been around for well over 200 million years, but this study shows it wasn't until the extinction of the dinosaurs that we had this burst of frog diversity that resulted in the vast majority of frogs we see today," said study co-author David Blackburn, associate curator of amphibians and reptiles at the Florida Museum of Natural History on the University of Florida campus.


This finding, published Monday in the U.S. journal Proceedings of the National Academy of Sciences air max scontate outlet , "was totally unexpected," Blackburn said.


The swift rise of frogs after the massive die-off was likely due to the fact that so many environmental niches were available after the animals occupying them disappeared.


"We think there were massive alterations of ecosystems at that time, including widespread destruction of forests," Blackburn said. "But frogs are pretty good at eking out a living in microhabitats, and as forests and tropical ecosystems rebounded, they quickly took advantage of those new ecological opportunities."