贵州麻江地区寒武纪杷榔动物群的群落组成和生态空间分析*

寒武纪特异埋藏化石库保存了海洋生物群落最原始的生态结构, 为群落生态研究提供了宝贵材料。贵州寒武纪斜坡相区的杷榔动物群(第4期)具有较高的生物多样性, 但定量生态学研究相对薄弱。本研究对贵州麻江地区杷榔动物群的新产地平定剖面进行化石采集和分类统计, 并运用多元数理统计方法开展定量化分析。鉴定出腕足动物、海绵动物、刺胞动物、节肢动物、软舌螺动物、古虫动物、开腔骨动物和曳鳃动物8个化石门类, 计31属33种, 划分出12种生态类型。其中, 腕足动物具有最高的个体丰度(占比61.5%), 节肢动物物种分异度最高(占比60%), 群落以底栖固着生态类型为主, 游泳捕食为辅。对比分析结果显示, 寒武纪海洋群落具有空间异质性, 且节肢动物在影响群落组成和生态空间利用上起决定性作用。随水体深度增加, 海洋生态群落中的表栖类群出现明显扩张, 也体现了环境对群落面貌的塑造作用。

Community composition and ecospace analysis of the Cambrian Balang Fauna in Majiang County, Guizhou Province

Cambrian Konservat-Lagerst?tten preserve the original states of marine communities and provide valuable materials for community ecological studies. However, few quantitative ecological analyses have been conducted on the Cambrian Balang Fauna (Stage 4, Series 2) from Guizhou Province. In this study, we report a new fossil assemblage from the Pingding section in Majiang County and perform multivariate statistical analyses. This fossil assemblage contains 31 genera and 33 species belonging to six phyla (Brachiopoda, Cnidaria, Arthropoda, Hyolitha, Chancelloriida, and Priapulida) and 12 ecological types. Among these phyla, brachiopods are the most abundant component (61.5%) whilst arthropods exhibit the highest taxonomic diversity at species level (60%). Furthermore, sessile benthos dominate the community followed by active swimming predators. By comparing this fossil assemblage from the Pingding section with communities from other Cambrian faunas, we confirm the heterogeneity among the Cambrian marine communities and suggest that arthropods play a crucial role in shaping the community structure and influencing ecospace occupation. Additionally, expansion of epibenthos in marine ecological communities with increasing water depth also reflects the role of the environmental factors in shaping the community structure.