导读：据斯泰勒回忆称，“这种动物从未上岸，一直生活在水中，它的皮肤又黑又厚，看起来就象剥过皮的老橡树；与身体的比例相比，它的头相当小，没有牙，只有两排扁平的骨头，一排在上，一排在下”。
对应考题：2010.01.15北美托福阅读题
Steller’s Sea Cow 斯泰勒的海牛
Steller’s sea cow was wiped out in 1768.
This large aquatic mammal was once a source of food and raw materials for many people living in the Northern Pacific region. Unfortunately, overhunting forced the species into extinction in 1768. Sea cows were first officially discovered by the German naturalist Georg Steller in 1741, although they had been a part of indigenous people’s way of life for perhaps thousands of years. Steller was traveling with the explorer Vitus Bering when he spotted a group of the cows near the Commander Islands. He was fascinated by them, and wrote about them in his journal. Fossil records show that at one time the animals lived all along the North Pacific coast, reaching as far south as Japan and California.
Sea cows were an important part of many native people’s lives. In addition to being eaten for food, sea cows’ skin was used to make durable boats. Also, their thick subcutaneous layer of fat made an ideal, odorless fuel. The regular hunting of the cows, however, reduced their numbers over time. And after Steller made them known to the European world, poachers quickly killed off the surviving herds.
Steller’s sea cows looked like a cross between a manatee and a seal, but they were much bigger than both these animals. Stretching 27 feet long and reaching estimated weights of up to 10 tons, sea cows were monstrosities in the water. Their characteristic whale-like tails and stumpy “arms” also set them apart from other water mammals. But despite their size and oddities, they were docile creatures, easy to track and kill. The cows couldn’t entirely submerge in the water and they usually traveled in groups, leaving trails of uprooted sea kelp. It wasn’t difficult for hunters to find them and, over time, kill them off to the point of extinction.
中文背景：
斯泰勒的海牛：毫无防御能力的动物(自1768年后灭绝)
这种海牛是在1741年由自然学者吉奥格.斯泰勒在白令海靠近亚洲海岸附近发现的，当时他正与探险家维特斯.白令一起进行冒险旅游。他发现的这种海牛身长7.9米(合25.9英尺)，重约3吨，比一般海牛或懦艮要大得多，看起来有些象海豹，但两只前肢结实有力，还有一条象鲸一样的尾巴。据斯泰勒回忆称，“这种动物从未上岸，一直生活在水中，它的皮肤又黑又厚，看起来就象剥过皮的老橡树；与身体的比例相比，它的头相当小，没有牙，只有两排扁平的骨头，一排在上，一排在下”。据斯泰勒称，这种动物十分温驯。根据发现的化石资料显示，斯泰勒的海牛从前曾广泛生活在北太平洋海岸，，向南直至日本和加利福尼亚。
由于它的灭绝速度非常之快，很可能也与其它现象一样，是人类进入这一地域的后果。现在仍有零星报道称在白令地区和格陵兰岛附近发现过貌似海牛的动物，因而有人认为今天仍有极少数量的斯泰勒海牛存活于世，至今这一观点仍有待证实。
