Abstract—

A distinct change in the taxonomic and ecological structure of assemblages of brachiopods of the order Spiriferida is observed at the Devonian and Carboniferous boundary of Transcaucasia. Representatives of the superfamily Cyrtospiriferoidea dominated in the assemblages in the Late Devonian, and became extinct by the end of the Devonian, while the Early Carboniferous is dominated by the superfamily Spiriferoidea. Cyrtospiriferoids represented a complicated subtype of the anchored ecological type ethologically associated with hard substrates, while the spiriferoids represented the main subtype of the anchor ecological type and the weighted subtype of the free-lying ecological type, replacing each other in ontogeny of brachiopods inhabiting mostly soft substrates. Although the Devonian-Carboniferous boundary in Transcaucasia lies within a continuous succession of lithologically uniform carbonate and carbonate-terrigenous rocks, a change in the diversity and ecological type of spiriferids indicates a change in the density of the substrate. This corresponds to a general global shift from the Devonian calcite sea to an aragonite Carboniferous sea, which affected the density of marine substrates. Thus, the stratigraphic procedure in this case can include the diversity analysis of both the taxonomic and ecological compositions of brachiopods.

中文翻译：

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跨高加索地区泥盆纪-石炭纪界的螺旋藻目腕足纲。

摘要—

在跨高加索地区的泥盆纪和石炭纪界观察到了螺旋藻科腕足类的分类学和生态结构的明显变化。超家族Cyrtospiriferoidea的代表在泥盆纪晚期的组合中占主导地位，并在泥盆纪末期灭绝，而早期石炭纪则由超螺旋藻主导。拟螺拟螺类代表了在生态学上与硬质基质相关的锚定生态型的复杂亚型，而拟螺螺类代表了锚定生态型的主要亚型和自由生态型的加权亚型，在腕足类的个体发育中相互替代基材。尽管跨高加索地区的泥盆纪-石炭纪界线是连续不断的岩性均匀的碳酸盐岩和碳酸盐-陆源岩连续分布的，但是螺线虫的多样性和生态类型的变化表明基质密度的变化。这对应于从泥盆纪方解石海向文石石炭纪海的总体变化，这影响了海洋基质的密度。因此，这种情况下的地层程序可以包括腕足类生物分类和生态组成的多样性分析。这对应于从泥盆纪方解石海向文石石炭纪海的总体变化，这影响了海洋基质的密度。因此，这种情况下的地层程序可以包括腕足类生物分类和生态组成的多样性分析。这对应于从泥盆纪方解石海向文石石炭纪海的总体变化，这影响了海洋基质的密度。因此，这种情况下的地层程序可以包括腕足类生物分类和生态组成的多样性分析。