|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
Trilobita - Harpida
It was reranked as the suborder Harpina by Fortey (1990); it was synonymized subjectively with Harpetida by Ebach and McNamara (2002); it was corrected as Harpida by Adrain (2011).
It was assigned to Ptychopariida by Harrington and Leanza (1957), Fortey (1990) and Sepkoski (1998); and to Trilobita by Adrain (2011).
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.
|R. A. Fortey 1990||Libristoma having small eyes placed anteriorly relative to glabella; cephalon broadly convex (sag. tr.) with long preglabellar area, and often a brim, with stout genal spines or genal prolongations of the brim; free cheeks narrow (tr.) or lost altogether, fused together; thoracic segments numerous (12 or more) and characteristically narrow (sag.) with long pleurae in contact along their length; pygidium relatively small and often transverse.|