Precambrian phosphatized embryos and larvae from the Doushantuo Formation and their affinities, Guizhou (SW China)  

作　　者：CHEN Junyuan CHI Huimei 

机构地区：[1]Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences, Nanjing 210008, China [2]Chien-Shiung Wu Laboratory, Southeast University, Nanjing 210096, China

出　　处：《Chinese Science Bulletin》2005年第19期2193-2200,共8页

基　　金：This work was supported jointly by the National Natural Science Foundation of China (Grant No. 40132010, 40302004)；Chinese Acad-emy of Sciences (Grant No. KZCX3 SW-14l) ； Ministry of Science and Technology of China (Grant No. G2000077700).

摘　　要：Weng,an phosphates of the Precambrian Dou-shantuo Formation, Guizhou (southwestern China) preserve a large number of exquisite biological structures, which are mostly micro-spherical and represent seaweeds, acritarchs and developing eggs related to various groups of metazoans. Here is a report of a variety of developing eggs and larvae, which are most probably of Cnidarian affinity. The eggs ex-amined in the study are composed of early cleavage embryos and two-layered gastrulae. The early cleavage embryos are radial and total cleavage with equal-size blastomeres. The gastrulae mostly bear a large archenteron, which is filled with yolk-degrading organic matter. Ovoid to fusiform planula-like larvae identified in thin sections under light microscope are mostly mouthless and their gastrovascularcavity is filled with possible yolk-degrading organic matter. They are likely representatives of non-feeding larva. The uncommon planula-like structures are hollow, with each having a mouth-like structure on its narrow end. We inter-pret them as feeding larva. Study of these embryos with pos-sible Cnidarian affinities shed new insight on the origin ofmetazoans.Weng＇an phosphates of the Precambrian Doushantuo Formation, Guizhou （southwestern China） preserve a large number of exquisite biological structures, which are mostly micro-spherical and represent seaweeds, acritarchs and developing eggs related to various groups of metazoans. Here is a report of a variety of developing eggs and larvae, which are most probably of Cnidarian affinity. The eggs examined in the study are composed of early cleavage embryos and two-layered gastrulae. The early cleavage embryos are radial and total cleavage with equal-size blastomeres. The gastrulae mostly bear a large archenteron, which is filled with yolk-degrading organic matter. Ovoid to fusiform planula-like larvae identified in thin sections under light microscope are mostly mouthless and their gastrovascular cavity is filled with possible yolk-degrading organic matter. They are likely representatives of non-feeding larva. The uncommon planula-like structures are hollow, with each having a mouth-like structure on its narrow end. We interpret them as feeding larva. Study of these embryos with possible Cnidarian affinities shed new insight on the origin of metazoans.

关 键 词：中国 贵州 寒武纪 磷酸盐晶胚 化石 生物学结构 

分 类 号：Q915.2[天文地球—古生物学与地层学]