Distinguishing characters of  include 

  • the length of the eye-lobe
  • the thick base to the spine on the librigena or ‘free cheek’
  • the character of the last thoracic segment and pygidium (tail-plate)
  • There are 21 thoracic segments in the known examples
    • whereas the very similar Bohemian species P. gracilis (which is known from a large number of complete examples) has only 20 segments.

In trilobites generally 

  • the mouth and stomach lay under the middle part of the cranidium (head-shield)
  • underlying the front part of the head is the hypostome, a large plate which is, in P. paradoxissimus, fused to the rostral plate
    • a structure is thought to be associated with a predatory mode of life.


  • Linnaeus termed them Entomolithus paradoxus, meaning “stone insect – against expectation” and assigned Greek letters to the species he recognised. 
    • Trilobites were known to Linnaeus, but not well understood. 
    • One of his specimens was a large, rather broad-bodied Paradoxides now held in Copenhagen. 
  • Wahlenberg recognised a narrow-bodied form he dubbed it Entomolithus paradoxissimus.  
  • Brongniart devised the generic name Paradoxides from Linnaeus’s “paradoxus”