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1974年在我国上前寒武系蓟县层型剖面蓟县系雾迷山组下部首次报道了一个新的叠层石群Pseudogymnosolen Liang et Tsao,近数年来在我国许多地区陆续发现该群分子。与此同时,又发现大量的形态上与Pseudogymnosolen具有一定相似性但又有明显区别的新的叠层石群。作者认为原假裸枝叠层石群(相当属)资料十分丰富,已有足够条件提升为超群Pseudogymnosolenidae(相当科)。此超群的叠层石具有固定的柱体形态(表1图2),局部柱体本身是由一系列紧密相连的假柱组成,故它们的分类位置应归于柱-层叠层石大类。但因叠层体微小(柱体直径一般小于1厘米),具较频繁的平行和微散开分叉,它们可以与柱-层叠层石大类的其他叠层石明显区分。在燕山地区,该超群的叠层石局部是由黑
A new monolithic group Pseudogymnosolen Liang et Tsao was reported for the first time in the lower part of the Wumishan Formation in Jixian, Jixian, in the Precambrian Jixian stratigraphic section of China in 1974. Pseudogymnosolen Liang et Tsao was recently discovered in many parts of China in recent years. In the meantime, a large number of new strata have also been found, which are morphologically similar to Pseudogymnosolen but have obvious differences. The author believes that the original fake naked-graded stony group (equivalent) is very rich in information, sufficient conditions have been promoted to superior Pseudogymnosolenidae (equivalent Division). This superb stackstone has a fixed column morphology (Table 1, Figure 2). The local column itself consists of a series of closely spaced fake columns, so their classification should be attributed to the column-strata. However, due to the small size of the laminate (generally less than 1 cm in diameter) and the more frequent parallel and diffusive bifurcations, they are clearly distinguishable from the other strata of the column-strata. In the Yanshan area, this superb stack of strata is partially black