【作者】 魏明瑞； 胡书生； 张雁；

【Author】 WEI Mingrui;HU Shusheng;ZHANG Yan;Beijing Natural History Museum;University of Florida;

【机构】 北京自然博物馆； 美国佛罗里达大学；

【摘要】 孢粉样品的测试结果表明,云南禄丰地区早侏罗世的植被以松柏类占较大优势,蕨类植物比较繁盛;而中侏罗世则以松柏类占绝对优势,蕨类植物衰落。原蜥脚类不可能觅食很高的松树树冠上的枝叶,主要是以蕨类植物和石松类植物为食;当时研究区没有苏铁植物存在,它们不可能以苏铁植物为食,这是对传统观念的冲击。蜥脚类不是水栖动物,而是陆生动物。它们以"三足"姿势觅食高大的松树树冠上的枝叶。与原蜥脚类一样,它们需要胃石来帮助磨碎食物。原蜥脚类代表了恐龙早期高处觅食的第一次辐射演化;蜥脚类起源于原蜥脚类,但与原蜥脚类相比,它们的食性发生重大改变。在蕨类相对较茂盛的早侏罗世是原蜥脚类时代,而在松柏类占绝对优势的中侏罗世则是蜥脚类的时代。更多还原

【Abstract】 According to the sporopollen analysis,the vegetation of Early Jurassic in Lufeng,Yunnan,China was dominated by pines,but ferns was still an important component of local ecosystem.In Lower Lufeng Formation(Early Jurassic) of Chuanjie Basin,Pinuspollenites accounted for 58.5% in the whole sporopollen assemblage,and the fern spores accounted for 41.5%.In Lower Lufeng Formation(Early Jurassic) of Lufeng Basin,Pinuspollenites accounted for 64.7% in the whole sporopollen assemblage,and the fern spores accounted for 32.4%.The vegetation of Middle Jurassic of Lufeng was dominated by pines,and ferns were only a minor part.In Upper Lufeng Formation(Middle Jurassic) of Chuanjie Basin,Pinuspollenites accounted for 92.2% in the whole sporopollen assemblage,and the fern spores only accounted for 4.6%.Although prosauropods were high browsers,with average body length of 3～5 m,they could not catch twigs or leaves of high pine trees(averaging 6～21 m high).We supposed that they were feeding on ferns.Since there were no Cycadophyta in studied area in Early Jurassic,prosauropods could not fed on Cycadophyta,which was a challenge to the traditional theory.Sauropods were not swamp-or lake-dwelling animals,but rather terrestrial herbivores.We supposed that they were feeding on twigs and leaves of pine trees.With the hind limbs and stout tail supporting their weight,they could probably fed tripodally.Like prosauropods,they used their gastroliths to breakdown the food stuffs they ingested.Prosauropods represented the first radiation of high browsing dinosaurs.With capability of high browsing,they replaced the short-necked,short-limbed,lower browsers and dominated the Early Jurassic.However,with the decline of ferns,they became extinct and were replaced by sauropods.In studied area,the Early Jurassic when there were plenty of ferns was the era of prosauropods,while the Middle Jurassic when pines dominated the flora was the era of sauropods.更多还原