Yue and Bengtson(1 997;1 998) make us to pay attention to the earliest Cambrian fossilized metazoan embryos.Based on recent observation of the fossils from Ningiang and Emei,Author came to the same conclusion that the...Yue and Bengtson(1 997;1 998) make us to pay attention to the earliest Cambrian fossilized metazoan embryos.Based on recent observation of the fossils from Ningiang and Emei,Author came to the same conclusion that they should represent various products from many taxa during differentstages oflife cycle.4 groups can be divided:1 . External structure or ornament of the oospheres(representing blastula) is various.2 . Oospheres(blastula) with lower tissue-differentiation.3 .Oospheres(blastula) with higher tissue-differentiation.4 .Pagoda-like larva(or polyp or transverse fission larva) .Many hypotheses concerning the biological entity of the spheres(fossils) , suchas Acritarch,algal,calcisphere,animal oosphere,sponge gemmule,and metazoan paleoembryo have been proposed.The idea that Olivooides-Punctatus developmentary succession is recognized by Yue and Bengston (1 997;1 998) ,has advanced the investigation of small shelly fossils to a new stage-researching the life展开更多
文摘Yue and Bengtson(1 997;1 998) make us to pay attention to the earliest Cambrian fossilized metazoan embryos.Based on recent observation of the fossils from Ningiang and Emei,Author came to the same conclusion that they should represent various products from many taxa during differentstages oflife cycle.4 groups can be divided:1 . External structure or ornament of the oospheres(representing blastula) is various.2 . Oospheres(blastula) with lower tissue-differentiation.3 .Oospheres(blastula) with higher tissue-differentiation.4 .Pagoda-like larva(or polyp or transverse fission larva) .Many hypotheses concerning the biological entity of the spheres(fossils) , suchas Acritarch,algal,calcisphere,animal oosphere,sponge gemmule,and metazoan paleoembryo have been proposed.The idea that Olivooides-Punctatus developmentary succession is recognized by Yue and Bengston (1 997;1 998) ,has advanced the investigation of small shelly fossils to a new stage-researching the life
