|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
Trilobita - Redlichiida - Biceratopsidae
It was assigned to Bristoliinae by Palmer and Repina (1993); to Olenellidae by Whittington et al. (1997); to Biceratopsinae by Lieberman (1999); and to Olenellida by Sepkoski (2002).
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.
|A. R. Palmer and L. N. Repina 1993||Bristohinae w ith posterior m argin of cephalon directed slightly posterolaterally to intergenal spine or intergenal swelling that is situated near slightly advanced genal spines. Preglabellar field short. Width of interocular area approximately half or more width of gla- bella at L2. Posterior tips of ocular lobes opposite Li. Third thoracic segment macropleural, with extremely long pleural spines; tips posterior to end of thorax. Prothorax of 13 segments; opisthothorax of at least 17 segments. Fifteenth segment lacks strong axial spine.|
|B. S. Lieberman 1999||Anterior cephalic border prominently separated from extraocular area by fur- row; plectrum absent; L4 contacts anterior border furrow; anterior margins of L4 at each side of midline deflected posteriorly at roughly 10 to 20 degree angle relative to transverse line; length (sag.) of L4 equal to 1.5 times length of L0 (sag.); L4 expands prominently dor- sally; lateral margins of L4 distal to lateral margins of L0; region of anterior part of ocular lobe between visual surfaces and L4 broad (tr.), one-third width of glabella at L1; ocular lobe without prominent ocular furrow; line from posterior tip of ocular lobe to junction of posterior margin of lobe with glabella forms roughly 45 degree angle with sagittal line; transverse profile of ocular lobes convex dorsally; posterior tips of ocular lobes developed opposite medial part of distal margin of L1; width (tr.) of interocular area greater than width of ocular lobe; S3 jaggedly convex, not conjoined medially; L2 and L3 do not merge; S2 convex anteriorly, conjoined medially; distal margins of L2 when proceeding anteriorly diverging; S1 conjoined medially; S0 convex anteriorly, not conjoined medially, proximal and distal ends on transverse line; L0, L1, L2 and L3 with axial spine; posterior margin of L0 convex posteriorly; prominent anastomosing ridges absent on extraocular area; width (tr.) of extraocular region opposite L1 equal to 75% of width of glabella at L1; genal spine near cephalic border directed posterolaterally at roughly 35 to 45 degree angle relative to sagittal line; genal spine short (exsag.), length approximately equal to length of first 2 to 3 thoracic segments; genal spine angle developed opposite medial part of distal margin of L0; intergenal angle deflected anteriorly at least 30 degrees relative to transverse line; medial part of posterior border between intergenal angle and L0 flexes posteriorly.|