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贵州瓮安埃迪卡拉纪陡山沱组(635—551Ma)上磷矿段保存了丰富的磷酸盐化动物胚胎化石,其中绝大多数为早期卵裂胚胎化石,原肠胚化石相对罕见。文中报道瓮安生物群中新发现的一种类似现代两栖动物胚胎的外包型腔原肠胚化石,并依据新的三维立体胚胎化石标本对瓮安陡山沱组原肠胚期动物化石的多样性及其可能的亲缘关系进行初步探讨,认为:1)“外包型腔原肠胚”和已有轴性分化的“外包型实体原肠胚”的发现为证明瓮安生物群中存在两侧对称动物提供了新的化石证据;2)“单极内陷型腔原肠胚”因胚体存在巨大空腔(囊胚腔和原肠腔)而难以被磷酸盐化精细保存,故在瓮安生物群中的化石记录稀少且亲缘关系不明;3)瓮安生物群中的“单极内移型腔原肠胚”和“分层型腔原肠胚”化石的可靠性尚有待更多的标本提供佐证。瓮安生物群中颇具多样性的原肠胚期动物化石为探索后生动物在晚新元古代的胚胎发育模式开拓了思路。
Guizhou Weng’an Ediacalaji Doushantuo Formation (635-551Ma) Phosphorus ore reserves on the rich animal embryonic fossils, most of them early cleavage embryo fossil, gastrula fossil relatively rare. In this paper, a new type of envelop gastrocnemius fossil resembling a modern amphibian embryo newly discovered in Weng’an biota is reported. Based on the new three-dimensional embryo fossil specimen, the diversity of animal fossils in gastrulation stage of Doushantuo Formation in Weng’an Sex and possible relationship between the two groups, and concluded that: 1) The discovery of “outsourced enterocolitization” and the already axial differentiated “outsourced entity” The presence of bilaterally symmetrical animals provides new fossil evidence; 2) “unipolar invagination gastrula” is difficult to be phosphatased due to the presence of large cavities in the embryoid body (the blastocyst and primitive intestine) The fossil record in Weng’an biota is sparse and the genetic relationship is unknown; 3) the “unipolar shift cavity gastrula” and “ ”The reliability of fossils remains to be confirmed by more specimens. The quite diverse gastrula animal fossils in the Weng’an biota opened the way for the exploration of late-Neoproterozoic embryonic development patterns of metazoans.