Taxonomy

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”