Data from: Evolutionary implications of a new transitional blastozoan echinoderm from the mid Cambrian of Czech Republic

The primitive blastozoan Felbabkacystis luckae n. gen. n. sp. is described from the Drumian Jince Formation, Barrandian area (Czech Republic) based on eleven fairly well-preserved specimens. Its unique body plan organization is composed of a relatively long stalk-like imbricate structure directly connected to the aboral imbricate cup of the test and of an adoral vaulted tessellate test supporting the ambulacral and brachiolar systems. Its bipartite test, called prototheca, highlights the evolution of the body wall among blastozoans. Felbabkacystis n. gen. shows the combination of plesiomorphic (imbricate stalk-like appendage) and derived features (highly domed peristome, elongate epispires). The new genus is interpreted as a transitional form between calyx-bearing and theca-bearing blastozoans, and is attributed to the new Family Felbabkacystidae. The lithology, the associated fauna and the possession of a long stalk suggest that Felbabkacystis was probably a low-level suspension feeder in relatively deep settings.本研究基于采自捷克共和国巴拉德地区德鲁姆阶金斯组（Drumian Jince Formation）的11件保存较为完好的标本，对原始芽茎动物（blastozoan）新属新种费尔巴卡囊海蕾（Felbabkacystis luckae）进行了系统描述。该物种独特的身体构型由两部分构成：一是与壳体反口面（aboral）覆瓦状杯状结构直接相连的细长柄状覆瓦状构造，二是支撑步带系统（ambulacral system）与腕羽系统（brachiolar system）的口面（adoral）穹顶状镶嵌壳体。其被称为原壳（prototheca）的二分壳体，揭示了芽茎动物体壁的演化历程。该新属兼具祖征（plesiomorphic character）——覆瓦状柄状附属构造，与衍征（derived character）——高度隆凸的口围（peristome）、延长的外鳃孔（epispires）。该新属被认为是具萼芽茎动物与具壳芽茎动物之间的过渡类群，并归入新建立的费尔巴卡囊海蕾科（Felbabkacystidae）。通过其产出地层的岩性（lithology）、伴生动物群以及长柄构造，可推测费尔巴卡囊海蕾大概率为栖息于较深水环境的底层滤食生物。