|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
Trilobita - Harpetida - Harpetidae
If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.
|P. A. Jell 1985||Cephalon sub-semicircular; lp furrow well impressed; alae distinct but low; occipital tubercle prominent; radial anastamosing caecal network on cheeks and brim with moderately large pits between caeca on brim gradually decreasing towards glabella; brim prolonged only a very short distance behind posterior of occipital ring, markedly concave posterolateral^ long genal spine at rear of prolongation; girder prominent, extending to tip of prolongation; check roll widened at level of posterior border furrow, extending adaxially almost as far as exsagitlal line of outer edge of eye tubercle.|