美国科学60秒 SSS 2012-10-09
时间：2013-06-19 08:24:30
搜索关注在线英语听力室公众号：tingroom，领取免费英语资料大礼包。
（单词翻译）
Sauropods like Brachiosaurus and Diplodocus were the biggest beasts to ever roam the Earth. And these dinosaurs1 had enormously long necks. Which poses an anatomical problem: they needed to move their necks side to side and up and down to graze, but that requires lots of muscles. And muscles are heavy. So how did they keep their heads from dragging on the ground?
It looked like the Sauropod's secret was thin riblike bones—some up to 10 feet long—that ran the length of their necks. Because when researchers examined slices of those bones under the microscope, they found that they aren't normal bone at all—they're
ossified2 tendons. That’s according to a study in the journal Biology Letters.
The researchers think those long tendons may have allowed the dinos to shift muscle mass from their necks onto their bodies—giving them a sort of "remote control" over their necks, while making the neck
lighter3 and more flexible. Not too different, in fact, from how herons do it today.
And that, the authors say, may have been the sauropods' key innovation.
Helping4 them to graze more
efficiently5, and stay neck and neck with other dinos.
分享到：
Error Warning!
出错了
Error page: /?aid=216262&mid=3
Error infos: Got error 28 from storage engine
Error sql: select `l`.`tag`,`l`.`index`,`l`.`level_id`,`b`.`id`,`b`.`word`,`b`.`spell`,`b`.`explain`,`b`.`sentence`,`b`.`src` from `new_wordtaglist` `l` left join `new_word_base` `b` on `l`.`tag`=`b`.`word` where `l`.`arc_id`='216262' and `l`.`level_id`>='' group by `b`.`word` order by `l`.`index` asc
