作者：邱占祥

摘要：Postschizotherium is one of the most puzzling forms, discovered from the late Cenozoic deposits in North China. Since its first discovery much speculation has been raised concerning its systematic position. Teilhard de Chardin, who described almost all the material collected in China at that time, had insisted all the time on referring it to the perissodactyl Family Chalicotheriidae. G. Simpson, and later most paleontologists who studied or once touched the problem, preferred to consider it an aberrant hyracoid. There were still others who compared it with various groups of Perissodactyla, such as paleotheres, titanotheres and anchitheres. The problem can not be considered as completely solved even now. One of the probable reasons for such a discrepancy may lie in the incompleteness of the material available for studying. In fact, all the material accumplated during more than 40 years consists of only a poorly preserved middle part of the skull, which practically shows nothing except two tooth rows of  P⁴-M³, three similarly brocken symphysial portions of lower jaws，as well as several isolated teeth. The best part of the material preserved,  P⁴-M³, unfortunately, shows nearly equal resemblance both to hyracoids and chalicotheres. Thus it can hardly be relied on as an useful criterion in deciding which Order the animal ought to be included in. The general structure of the preserved part of the lower jaw is really much more similar to that of hyracoids, especially in the enlargement of the two tusk-like incisors. But the material is too fragmentary to give more definite clue to its true nature.
　  During the visit to Tianjin Natural History Museum, the author found by chance a lower jaw, which was in a drawer without any indication of provenance. A first glance was enough to determine that it was some kind of hyracoids. Owing to the rare occurrence of the hyracoid fossils in China, the unexpected find attracted the author`s attention at once. After a further investigation, it revealed that the specimen did represent a lower jaw of Postschizothcrium. Since a larger portion of the lower jaw is preserved, its hyracoid nature is for the first time so clearly shown. This is the reason why it is worthy studying and publishing as soon as possible.

卷期：19卷 01期