Superfamily Dikelocephaloidea
diagnostic characters boldfaced:
Here are two representative members of the Dikelocephaloidea:
| ORDER
ASAPHIDA
Superfamily Anomocaroidea Superfamily Asaphoidea Superfamily Cyclopygoidea Superfamily Trinucleioidea Superfamily Dikelocephaloidea Superfamily Remopleuridoidea |
Here are two representative members of the Dikelocephaloidea:
| Dikelocephalus | Saukia |
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Compare the pictorial approach above to the narrative equivalent below (salient features in color):
| Superfamily Dikelocephaloidea
Cephalon: with opisthoparian sutures, glabella typically truncate anteriorly and squat, 1-4 pairs of lateral furrows, 1p may be transglabellar; preglabellar field variable, sometimes absent, palpebral ridge typically well-defined, but separate from axial furrow (compare to sister group Remopleuroidea); genal spines typically present, of various length; median ventral suture rarely lost to secondary fusion; hypostome conterminant Thorax: 8-12 segments, axis convex, pleurae typically wider than length of axis, typically with short, pointed ends (longer in Loganellidae). Pygidium: micropygous to isopygous, variable shape, axis often extends majority of length, sometimes with post-axial ridge, posterior margin smooth or spined (1-5 pairs of marginal spines) Families: Dikelocephalidae, Saukiidae, Ptychaspididae, Eurekiidae, Loganellidae. Representative Genera: Dikelocephalus, Saukia, Eurekia, Loganellus. Other notes: Dikelocephaloidea is thought of as a sister group to Remopleurididoidea |
