The first ever description of a diatom was of the colonial diatom Bacillaria "paradoxa" (Müller, 1783).  Colonies are shown in various configurations between which they can smoothly transition on a time scale of seconds. 

 
  Part of: Gordon R (2016) Partial synchronization of the colonial diatom Bacillaria "paradoxa". Research Ideas and Outcomes 2: e7869. https://doi.org/10.3897/rio.2.e7869