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原牙形类和牙形状化石是早寒武世微小骨骼化石中非常特征的一个类群。自二十世纪70年代以来,这些齿状的微型磷质骨片化石在中国下寒武统含小壳化石地层中被大量发现,据统计已描述有25属52种。通过文中的评述和讨论,证实其中的一些属种是次异名或属于无效的分类名称,还有一些在归属上尚存在疑问。通过对原牙形类和牙形状化石定义的讨论,将先前指定为原牙形类的13个属进行了分类评述。表明其中的5个属是次异名,还有2个属是未知的节肢动物。其它的12个牙形状化石属中也有5个属是次异名,它们不仅显示了有多种动物亲缘的牙形状形态,而且大多属于绝灭生物,只有Beshtashella和Paraformitchella(=Beshtashella)被指定为软体动物。文中还简要地讨论了大多数属的时空分布,包括3个阶段的原牙形类地层分布,这不仅具有划分对比地层的意义,而且还反映了原牙形类的演化趋势。
Protoceptor and tooth-shaped fossils are a very characteristic group of pre-Cambrian microfossil fossils. Since the 1970s, these dentate microporous phosphorus fossils have been extensively found in the Lower Cambrian, small shell fossil formations in China. According to statistics, 52 genera and 25 species have been described. Through the comments and discussions in the text, some of these genera are confirmed as sub-synonyms or ineffective taxonomic names, while others still have some questions about belonging. Thirteen species, previously designated as Protoceiraus, were classified by reviewing the definition of Protoceratops and Tooth shape fossils. Which shows that 5 of them are synonymous, and 2 are unknown arthropods. Five other genera of 12 other tooth-shaped fossils are synonymous. They show not only the shape of the tooth with many species of animals, but mostly extinct creatures, only Beshtashella and Paraformitchella (= Beshtashella) Molluscs The paper also briefly discusses the spatiotemporal distribution of most genera, including the distribution of the three stages of the primitive alchemy, which not only has the significance of dividing and contrasting strata, but also reflects the evolutionary trend of the primitive dentition.