科学家发现了一种生活在约1.65亿年前湖泊和河流中的史前新物种动物。
Scientists have discovered a new species of prehistoric animal that swam in lakes and rivers around 165 million years ago.
这种毛茸茸的水獭状生物，名为巨尾兽松氏种（Megacauda sungei），生活在今天的中国地区，当时恐龙仍在统治地球。
The furry, otter-like creature, called Megacauda sungei, lived in what is now China, at a time when dinosaurs roamed the Earth.
科学家表示，它拥有类似海狸的宽阔扁平尾巴，很可能是一名优秀的游泳者。
Scientists say it had a wide, flat tail like a beaver and was probably a good swimmer.
专家表示，这一发现有助于他们更好地理解早期哺乳动物在恐龙时代是如何生活的。研究人员在中国内蒙古地区的湖泊沉积岩中发现了该化石。
Experts say discovery could help them better understand how early mammals lived during the age of dinosaurs. Experts came across the fossil in China's Inner Mongolia region, in rock formed from lake sediment.
该化石保存状况良好，使科学家能够观察到该动物的毛发和皮肤证据，从而重建其外貌。
The well-preserved fossil meant that scientists could see evidence of the animal's fur and skin, helping them build a clearer picture of what it looked like.
巨尾兽松氏种生活在侏罗纪时期，即恐龙时代，体长约50厘米，体重1至2公斤。
Megacauda sungei lived during the Jurassic Period in the age of dinosaurs and was around 50 cm long, weighing 1 to 2 kg.
研究人员称，它的游泳方式类似鸭嘴兽，捕猎方式类似水獭，尾巴则类似海狸。它生活在湖泊和河流中，以鱼类和蝾螈为食。
Researchers say it swam like a platypus, hunted like an otter and had a tail similar to that of a beaver. It could be found in lakes and rivers hunting fish and salamanders.
研究合著者托马斯·马丁（Thomas Martin）来自波恩大学，他解释道："它通过前肢和后肢划水，并利用尾巴做波浪状运动来游泳。""它可能在河岸或湖岸挖掘洞穴作为栖息地。"
Study co-author Thomas Martin from the University of Bonn explained: "It swam by using its front and hind legs for paddling and performing undulating movements with its tail. "It probably dug burrows in the river banks or lake shores."
该研究的资深作者哲西·卢奥（Zhe-Xi Luo）来自芝加哥大学，他认为巨尾兽可能在夜间或黎明、黄昏时段活动。
Zhe-Xi Luo, the study's senior author from the University of Chicago, said Megacauda may have been active at night or around dawn and dusk.
他补充说，它必须时刻警惕肉食性捕食者。"对巨尾兽的捕食威胁很可能来自有羽毛的兽脚类恐龙，"卢奥说。
He added that it would have had to look out for meat-eating predators. "The predatory threat against Megacauda would likely be from the feathered theropod dinosaurs," Luo said.
科学家还认为，巨尾兽是目前已发现的最古老的半水生哺乳动物类动物。
Scientists also believe Megacauda to be the oldest-known semiaquatic mammal-like animal that has been discovered so far.