史前怪兽探秘
所属栏目：科学世界
所属频道：CCTV-10科教
年份：2010
展开全部
简介：就在古食肉类不断发展的同时，从古新世的一种古食肉类--古猫兽类当中，分化出了一支进步的类型，它们的裂齿由第四上前臼齿和第一下臼齿组成。从此，一种新型的食肉动物--食肉目哺乳动物出现了。这种前移的裂齿构造使撕裂肉食的工作更有效率，再加上其它一系列进步的体制结构，食肉目哺乳动物开始发展起来，当大多数古食肉类在始新世末灭绝以后，它们从渐新世开始完全取代了古食肉类的地位。古食肉类中只有鬣齿兽类一支延续到上新世早期。收起
![[em:1:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/1.gif)
![[em:3:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/3.gif)
![[em:4:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/4.gif)
![[em:5:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/5.gif)
![[em:6:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/6.gif)
![[em:7:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/7.gif)
![[em:8:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/8.gif)
![[em:9:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/9.gif)
![[em:10:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/10.gif)
![[em:11:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/11.gif)
![[em:12:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/12.gif)
![[em:13:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/13.gif)
![[em:14:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/14.gif)
![[em:15:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/15.gif)
![[em:16:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/16.gif)
![[em:17:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/17.gif)
![[em:18:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/18.gif)
![[em:19:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/19.gif)
![[em:20:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/20.gif)
![[em:21:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/21.gif)
![[em:22:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/22.gif)
![[em:23:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/23.gif)
![[em:24:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/24.gif)
![[em:25:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/25.gif)
![[em:26:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/26.gif)
![[em:27:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/27.gif)
![[em:28:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/28.gif)
![[em:29:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/29.gif)
![[em:30:]](http://p2.img.cctvpic.com/photoAlbum/templet/common/DEPA1406601454073701/30.gif)
