In any collection of Upper Palaeozoic crinoid columnals, dominated by the circular and the pentagonal, the elliptical articular facets of platycrinitid monobathrids stand out. One of the geologically youngest regions from which platycrinitids are known is the Permian (Artinskian to Roadian) of the Basleo area of West Timor, from which over a dozen species have already been described from thecae. Platycrinitid columnals and pluricolumnals from West Timor are dominated by nodals that are strongly tuberculated (= platycrinitid sp. D). These may have been to deter benthic vagile invertebrates, such as parasitic(?) platyceratid gastropods, from using the column as a route to the crown. One pluricolumnal (platycrinitid sp. A) is reminiscent of the proxistele of Platycrinites nikondaense Broadhead and Strimple, from Alaska. Two forms of nodals could not be more disparate, one (platycrinitid sp. B) having an unsculptured latus, in contrast to doughnut-like platycrinitid sp. C, where an epifacet is broad and circular. Episkeletozoans and epizoozoans are commonly bryozoans and tabulate corals; the boring Oichnus paraboloides Bromley is a domicile rather than evidence of predation or parasitism. In short, the platycrinitids were thriving and interacting with a diversity of invertebrate groups shortly before their demise at the end of the Permian.

在任何以圆形和五边形为主体的上古生界海百合柱状构造中，单斜cri的椭圆形关节面尤为突出。西帝汶巴斯勒地区的二叠纪（二叠纪（Artinskian至Roadian））是已知的板状辫状地质中最年轻的区域之一，已经从海藻中描述了十几种。来自西帝汶的斜纹甲column柱和多柱状柱被结节强烈的结节所支配（=斜纹甲藻D.）。这些可能是为了阻止底栖易变的无脊椎动物，例如寄生（？）桔小腹足纲动物，将其用作通往冠的途径。一个胸膜腔（platcricrinitid sp。A）让人联想到Platectrinites nikondaense的proxistele。来自阿拉斯加的Broadhead和Strimple。两种形式的节点是完全不同的，与环形甜甜圈状的platycrinitid sp相比，其中一种（platycrinitid sp。B）具有未雕刻的tus。C，主语是广泛且圆形的。附生动物和附生动物通常为苔藓动物，并成表珊瑚。无聊的Oichnus paraboloides Bromley是一个住所，而不是掠夺或寄生的证据。简而言之，鸭嘴兽在二叠纪末期消亡之前不久就蓬勃发展，并与各种无脊椎动物群体相互作用。