Paradoxides paradoxissimus is found in

  • sandstones
  • dark mudstones
  • limestones

Stratigraphically, it is particularly characteristic of the middle part of the Middle Cambrian, which in Scandinavia is termed the P. paradoxissimus Superzone.

 In modern classification, the stratigraphical range is in the early Drumian Stage and it also ranges down into the top of the as yet un-named stage preceding the Drumian.