The genus contains a single species, Cambropycnogon klausmuelleri, represented by presumed larval remains from the Upper Cambrian Orsten, having been referred to before description as "Larva D".

Cambropycnogon is covered in small spines roughly 1 micrometer long, as well as larger thorns behind its gnathobases.

Its chelicerae are short and stout, resembling pincers, and the larva has a relatively large head shield.

Cambropycnogon's morphology matches that of early sea spider larvae such as the protonymph and semaphoront, with it being markedly distinct from all other Orsten fossils.

[1] Cambropycnogon derives from its assumed position within Pycnogonida, as well as the fact that it dates from the Cambrian.