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11件保存相对完好的标本，对采自捷克共和国巴兰德地区德鲁姆阶金采组的原始芽生动物（blastozoan）费尔巴伯克囊胚（Felbabkacystis luckae）新属新种（n. gen. n. sp.）进行了描述。该物种独特的躯体构型由直接连接壳体反口覆瓦状杯的细长茎状覆瓦状结构，以及支撑步带与纤毛腕系统的口方拱起镶嵌状壳体组成。其被称为原壳（prototheca）的二分壳体，揭示了芽生动物体壁的演化历程。费尔巴伯克囊胚新属兼具祖征（茎状覆瓦状附肢）与衍征（高度隆起的口围、延长的围鳃孔（epispires））。该新属被认为是具萼芽生动物与具壳芽生动物之间的过渡类群，并被归入新建立的费尔巴伯克囊胚科（Felbabkacystidae）。结合岩性特征、伴生动物群以及该类群拥有的长茎结构，我们推测费尔巴伯克囊胚大概率为栖息于相对较深生境的底层悬浮摄食者。