封面说明：中间乌米兽(Urmiatherium intermedium)的生态复原图。近处为两只雄性乌米兽，远处为两个以雌性个体为主的小群。中间乌米兽的角器形态特别，额骨和顶骨表面均发育有赘生骨疣，其表面有角质覆盖。在雄性个体中，角器向前延伸至眼眶之前，向后达顶骨后缘。真正的角心退化，位置靠后。晚中新世的临夏盆地气候温暖干旱，为开阔的稀树草原环境。复原图中草地以禾本科植物为主，近处绘有十字花科和藜属植物，远处为柳树。详见史勤勤等人文。(绘图：史勤勤)
Cover image: The ecological reconstruction of Urmiatherium intermedium. The two bovids nearby are male and the two groups from a distance are mainly female. The horn apparatus of U. intermedium is unique. The exostoses are developed on both frontal and parietal, and covered by sheath. In male individual, the horn apparatus is very large, expanding forward to the level anterior to the orbit, and backward to the rearmost point of the parietal. The horn proper is short and posteriorly positioned. The habitat of the Linxia Basin in the Late Miocene is supposed to be open grassland, warm and semi-arid. Grass, goosefoots, crucifers and willows are illustrated in the reconstruction. See details in the paper of Shi et al. (Illustrated by Shi Qinqin)
