Restudy of Proexenocrinus inyoensis Strimple and McGinnis, 1972, shows that this earliest-known rhodocrinitid diplobathrid camerate crinoid (late Floian, Early Ordovician) expresses the only known record of ambulacral floor plates within pinnules. These pinnule floor plates are remarkably conserved plesiomorphic expressions, with anatomy similar to floor plates of some of the earliest pentaradiate echinoderms, although on a smaller scale. Proexenocrinus floor plates provide direct skeletal evidence that the general resemblance of blastozoan (eocrinoid, diploporan, rhombiferan) brachioles and crinoid pinnules is the product of homoplasy. Proexenocrinus posterior cup morphology is interpreted to include an anitaxis, a distinctive posterior interray morphology.

中文翻译：

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针叶中底板的第一次记录和rhodocrinitid dilobathrid camerate crinoids中最早期的反抗记录

重新研究稻草原虫Strimple 和 McGinnis，1972 年表明，这种已知最早的 rhodocrinitid dilobathrid camerate 海百合（弗洛里纪晚期，奥陶纪早期）表达了唯一已知的在小叶内的步行底板记录。这些针状底板是非常保守的拟形表达，其解剖结构类似于一些最早的五辐射棘皮动物的底板，尽管规模较小。甲壳虫底板提供了直接的骨骼证据，证明囊胚动物（始海贝类、双孔类、菱形类）腕骨和海百合小叶的一般相似性是同质的产物。甲壳虫后杯形态被解释为包括反轴，一种独特的后部间形态。