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山西保德第30地点发现了两种跳鼠化石,主要是三趾跳鼠Dipus fraudator,还有少量的五趾跳鼠Paralactaga cf.P.suni。这个跳鼠组合虽然种类不如内蒙古二登图动物群中的丰富,但其优势类群和组成比例都与后者非常相似。而与陕西蓝田灞河组发现的跳鼠组合相比,两者相差很大,后者以Protalactaga为主,虽然可能有一颗颊齿属于Paralactaga,但其明显比所有已知的种类原始。保德的跳鼠虽然只是该地区首批详细研究的小哺乳动物化石,但已经表明保德动物群和灞河动物群在小哺乳动物组成上也差异显著,进一步证实了灞河期和保德期动物群的截然不同,支持了灞河期的有效性。分析表明,跳鼠从10 Ma以后都是与高冠食草动物伴生,显示出其耐旱性。因此,保德第30地点和相关层位应该是开阔草原环境,这与之前根据大哺乳动物组合及牙齿稳定同位素分析所恢复的生态环境一致。由于缺乏有效的地理隔离,保德地区第30地点和第49地点的生态差异显然不是空间上的,而是时间上的。
There are two types of jumper fossils found in Baode, Shanxi Province, mainly the Dipus fraudator, and a few Paralactaga cf.P.suni. Although this type of jumper is not as rich as that of Inner Mongolia Erdengtu fauna, its dominant group and composition ratio are very similar to the latter. However, compared with the combination of jockeys found in Lantian group in Lantian, Shaanxi Province, there is a great difference between the two groups. The latter is dominated by Protalactaga. Although one cheek tooth may belong to Paralactaga, it is significantly more primitive than all known species. Although only the first mammalian fossils studied in detail in the area, the Baode’s jumper, however, has shown that there is also a significant difference in the composition of the small mammals between the Baode Animal Group and the Hehe Animal Group, further confirming that Bahe He and Baode The very different fauna of the period supports the validity of the 灞 He period. Analysis showed that jabs were associated with high crown herbivores from 10 Ma and showed their drought tolerance. Therefore, the location of Pohutu 30 and related horizons should be open grassland environments consistent with the previously restored ecological environment based on large mammalian combinations and stable dental isotope analysis. Due to the lack of effective geographical isolation, the ecological differences between the 30th and 49th locations in Baode District are obviously not spatial but temporal.