|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
Trilobita - Redlichiida - Olenellidae
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. D. Pack and H. B. Gayle 1971||A relatively smooth cephalon with well defined border of medium width, rounded genal angles and no genal spines. Glabella characterized by indistinct lat eral and axial furrows. Palpebral lobes short,directed upward and posteriorly, close along the sides of the glabella extending from the postero-lateral parts of the anterior glabellar lobe. Small eyes located laterally below the palpebral lobes slightly behind center of the glabella. Thorax consists of 15 prothoracic segments and 10 or more opisthothoracic segments. Third prothoracic segment is strongly macropleural and the fifteenth segment bears a long axial spine.|
|A. R. Palmer and L. N. Repina 1993||Biceratopsinae with posterior margin of cephalon nearly straight. Genal angles broadly rounded; genalandintergenalspinesabsent.Preglabellarfield present; sagittal length equal to or less than that of border. Ocular lobes prominent, close to glabella; posterior tips opposite SI, elevated above top of glabella. Opisthothorax of at least 11 segments.|