Largest Ediacaran discs from the Jodhpur Sandstone,Marwar Supergroup,India: Their palaeobiological signi?cance

Ediacaran discs from the Jodhpur Sandstone of the Marwar Supergroup, Rajasthan, exhibit a wide size ranging from a few millimetres to 75 cm in diameter. Exceptionally large size of the discs in these rocks represent the largest reported so far from any Ediacaran assemblage. Although, larger medu-soid discs have been reported from USA, they are from the middle Cambrian and even younger rocks. Presence of microbial mats and weed-like structures with well preserved hold fasts and horizontal rhizome-like structures in association with some of these large-sized discs support their animal affinity, which probably feed on this weed-like vegetations. This association also supports their benthic habitat. Unlike the general trend of sudden increase in size of organisms in Ediacaran period and further decrease in size during Cambrian, these discs continued increasing in size in Cambrian also.     

埃迪卡拉动物群

是位于澳大利亚南部的埃迪卡拉地区,生活在68～6亿年前的前寒武纪-大群软体躯的多细胞无脊椎动物。包括腔肠动物门、节肢动物门和环节动物门等8科22属31种低等无脊椎动物。1960年召开的第22届国际地质会议正式命名该化石群为”     

埃迪卡拉动物群

是位于澳大利亚南部的埃迪卡拉地区,生活在68～6亿年前的前寒武纪-大群软体躯的多细胞无脊椎动物。包括腔肠动物门、节肢动物门和环节动物门等8科22属31种低等无脊椎动物。1960年召开的第22届国际地质会议正式命名该化石群为“埃迪卡拉动物群”。埃迪卡拉动物群的发现．初步解开了寒武纪初期突然大量出现各门无脊椎动物化石的所谓“进化大爆炸”之谜。埃迪卡拉生物化石出土越多．反而越没有规律．这些化石到底是什么、什么年代也有很多争论。