Note that the world 's richest deposits of fossils from the oligocene epoch are found in the badlands .

需要注意的是世界上渐新世年代最丰富的化石沉积物却是在坏地发现的。

Fossil plants from the eocene and oligocene epochs indicate that what 's now the qinghai-tibet plateau enjoyed a tropical-subtropical rainforest environment with growing areas of temperate flora in some mountainous areas .

始新世和渐新世时代的植物化石表明，现在的青藏高原曾经拥有过赤道-次赤道附近的雨林气候，一些山脉曾生长着湿润气候的植物群落。

They have also unearthed some clues from the ensuing oligocene , when the modern suborders of cetaceans-the mysticetes ( baleen whales ) and the odontocetes ( toothed whales ) - arose .

在随后的渐新世地层中，他们也找到了一些线索；须鲸亚目（有鲸须的鲸鱼）与齿鲸亚目（有齿的鲸鱼）就是在那时候分化的。

Since tha latest of cretaceous , the xiihu sag had been undergoing rifting stage during the paleocene and the eocene , inversion stagc during the oligocene and the miocene , and regional subsidence stage during the pliocene and the quaternary .

晚中生代末期以来，经历了古新世-始新世的裂谷盆地阶段。渐新世-中新世的盆地反转阶段和上新世-第四纪的区域沉降阶段。

Larger foraminifera from the upper oligocene of the venetian area , north-east italy .

意大利东北部威尼斯地区上渐新统大有孔。