Almost within grasp: Crinoid organs rendered 3-dimensionally

Three-dimensional reconstructions of organs and tissues of different crinoid species are presented, all calculated by the aid of the reconstruction software Amira (R). The stacks have been compiled in three different ways: 1) traditional serial sections, 2) a new etching-refilling method and 3) Micro-CT. To create models of non-mineralized tissues and organs, traditional series of paraffin sections are still appropriate. For the reconstruction of the stereom, especially its fine details, e.g. in the region where new columnals are formed, an elaborate technique of etching and refilling is presented leading to pin-sharp models. To studying gross anatomy mainly of the skeleton -, Micro-CT is most valuable. However, its application is limited by resolution and data amount. Such models, maybe enriched by special effects, e.g. colour-marked nerve cords within partly transparent parts of the skeleton can facilitate teaching crinoid anatomy. The link to our home page is given from where snapshots of this paper's figures and surface-data files of 3D-models can be downloaded, as well as the link to a free demonstration copy of Amira (R) for rendering of the 3D-models.