北京下白垩统芦尚坟组叶肢介的生物地层学

THE CONCHOSTRACAN BIOSTRATIGRAPHY OF THE LOWER CRETACEOUS LUSHANGFEN FORMATION IN BEIJING

叶肢介化石是我国北方中生代生物群的重要成员之一,对古环境恢复和生物地层对比具有重要意义。北京西下白垩统芦尚坟组含丰富的昆虫、介形虫、植物、孢粉等化石,还发现了鱼和恐龙等脊椎动物化石,但叶肢介化石以前并无正式报道。芦尚坟组及其上覆夏庄组的昆虫化石组合被称为"芦尚坟昆虫群",对京西地区早白垩世中晚期的古生物学和古生态学研究具有重要意义。本文描述产自北京市丰台区贺照云村附近芦尚坟组第四段的Eosestheria(东方叶肢介)1新种,认为芦尚坟组的叶肢介群落为衰落型Eosestheria群,与上覆夏庄组的Yanjiestheria(延吉叶肢介)群差异较大,与辽西阜新组的叶肢介群落联系紧密。我们认为芦尚坟组和阜新组时代接近,约为Aptian晚期。

The Lower Cretaceous Lushangfen Formation of Southwestern Beijing is a set of alluvial fan sedi- ments consisting of siltites, lithic sandstones, conglomerates and other terrigenous sediments which yields abundant fossil fishes, dinosaurs, insects, eonchostracans, ostracodes, plants, spores and pollen. Conchostracans have never been reported from the Lushangfen Formation to date.