化石居群具有丰富的生物学与生态学内涵，相关研究是古生物学和古生态学的重要内容之一。通过研究居群，能够了解其生长规模的变化及结构，并推测其生长环境。在云南曲靖龙王庙采石场志留系关底组下部采集到一层腕足类，以无洞贝 Atrypoidea foxi Jones这一种占优势，其中铰合标本共计381枚。通过居群结构分析，其大小-频率曲线呈正态分布且略微负倾，显示成年个体标本占居群的主体；生存分析显示幼年到成年个体曲线略微上凸，成年至老年大个体曲线下凹，暗示多数个体能发育至成体甚至老年大个体，这表明其所属环境适宜其生存。回归分析显示：该种个体生长过程中有些大个体变得较为横宽；大个体的壳厚不稳定；随着个体凸度变大，其槽隆发育程度逐渐增强。考虑到腕足动物个体大小受长宽厚综合影响，用体积作为指标来表达个体大小更为准确。结合已有研究，本文用密度法拟合出腕足动物体型大小公式，可为相关研究提供参考。

Since fossil population contains rich ecological information, related studies are important in palaeontology. By researches on population of Atrypoidea foxi Jones,the structure and ecological environment of population can be evaluated.Brachiopods collected from the lower Kuanti Formation exposed at a stone quarry at Longwangmiao Village in Qujing,Yunnan are dominated by Atrypoidea foxi Jones(Brachiopods),with 381 conjoined valves of the species.A good state of preservation suggests the original condition of the population may be revealed.The population structure was analyzed.The sizefrequency curve fitting normal distribution and slightly negatively skewed,suggests the adult individuals are predominant in this population.Survivorship curve is convex from small to adult individuals and concave from adult to old stage,reveal that most individuals can develop to adult even older individuals,which suggests a suitable living environment.Regression analysis shows that some larger individuals tend to be wider;meanwhile,the shell’s thickness is not stable for large individuals.Furthermore,as an individual becomes more convex rather than longer and wider,the depth of its sulcus is increased.Considering the size of brachiopods affected by length,width and thickness,body volume should be adopted as an index to represent body size.Based on a published study and"density method",a new empirical formula is given to calculate body volume of atrypides.

国家自然科学基金(41472006，41521061，41530103)资助