|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
Trilobita - Redlichiida - Biceratopsidae
It was assigned to Olenellinae by Harrington (1956) and Palmer and Repina (1993); to Olenellidae by Whittington et al. (1997); to Bristoliinae by Lieberman (1999); and to Olenellida by Sepkoski (2002).
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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.
|H. J. Harrington 1956||Olenellinae with well advanced genal spines. Metagenal spines ab- sent in the adult. Metagenal angle sub-rectangular. Glabella parallel-sided with three pairs of lateral glabellar lobes, the an- terior (4p) narrower than the remainder and ill-defined. Frontal glabellar lobe not expanded, evenly rounded anteriorly, slightly encroaching over anterior border of cephalon. Eye lobes short, posterior, reaching level of mid-length of preoccipital glabellar lobe. Cephalic border wide, slightly raised andlflat.|
|A. R. Palmer and L. N. Repina 1993||Olenellinae with external surface smooth. Genal spines strongly advanced; genal spine angle anterior to S2. Intergenal angle nearly a right angle. Preglabellar field absent. Posterior tips of ocular lobes opposite ante- rior part of LI.|
|B. S. Lieberman 1999||Length (exsag.) anterior cephalic border near but not directly anterior to frontal lobe very long, equal to length (sag.) of L1 and L2; length (sag.) L4 equal to 1.5 times length (sag.) of L0 and L1; distal margins of L2 subparallel; S0, S1 not conjoined medially; L0 smooth, convex posteriorly; genal spine near cephalic border directed posterolaterally at 35 to 45 degree angle relative to sagittal line, length (exsag.) equal to four times length (sag.) L0; genal spine angle opposite medial part of distal margin of L3; cephalic posterior border transverse between intergenal angle and L0.|