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|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
Trilobita - Redlichiida - Wanneriidae
It was assigned to Mesonacidae by Walcott (1910); to Wanneriinae by Palmer and Repina (1993); to Olenellidae by Whittington et al. (1997); to Wanneriidae 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.
|A. R. Palmer and L. N. Repina 1993||Olenellidae with L4 enlarged. Posterior margin of cephalon straight or curved backward towards base of genal spine. Intergenal spine absent. Preglabellar field absent. Posterior tips of ocular lobes opposite or anterior to occipital furrow. Thorax of 17 segments, not divided into prothorax and opisthothorax; third segment unmodified; fifteenth segment bearing long axial spine. Pygidium small, subquadrate, with prominent median notch. External sculpture reticulate; polygons may have central granule. On well-preserved specimens, boundaries of polygons marked by rows of perforations on underside of exoskeleton.|
|B. S. Lieberman 1999||Length (exsag.) anterior cephalic border near but not directly anterior to frontal lobe equal to length (sag.) of L0; cephalic anterior border not prominently separated from extraocular area by furrow; frontal lobe of glabella contacts anterior border furrow; length of L4 (sag.) equal to length (sag.) of L0 and L1; posterolateral margins of L4 divergent anteri- orly, distal to lateral margins of L0; anterodistal margins of L3 formed by ocular lobes; distal margin of L3 convex outward; S3 carat shaped, not conjoined medially; distal margins of L2 diverge anteriorly; posterior tips of ocular lobes developed opposite medial part of distal margin of L1; L0 with lateral lobes absent, node present; line between ends of S2 transverse; S0, S2 convex anteriorly; length (exsag.) of genal spine equal to length (sag.) of first four to five thoracic segments; intergenal spine faintly developed; intergenal angle developed poste- rior to point half way between ocular lobes and genal spine; anterior margin of thoracic pleural furrow on third segment parallels transverse line axially, abaxially flexes strongly pos- teriorly; thoracic pleural furrows extend only half width of inner pleural region; prominent spine of length (sag.) five thoracic segments present on 15th axial ring, width (tr.) of base of spine nearly as wide as axis of segment; length (sag.) of pygidium equal to width (tr.).|