Superfamily Trinucleioidea
diagnostic characters boldfaced:
Here are representative Trinucleioidea:
| ORDER
ASAPHIDA
Superfamily Anomocaroidea Superfamily Asaphoidea Superfamily Cyclopygoidea Superfamily Trinucleioidea Superfamily Dikelokephaloidea Superfamily Remopleuridoidea |
Here are representative Trinucleioidea:
 Cryptolithus Trinucleidae |
 Ampyx Raphiophoridae |
 Seleneceme Alstaspididae |
| Superfamily Trinucleioidea
Cephalon: Opisthoparian or marginal facial sutures, generally eyeless; glabella typically convex and pyriform, with 3 or fewer pairs of furrows, preoccipital glabellar tubercle sometimes present; usually long genal spines. Thorax: usually 5 – 8 segments, but only 2-3 segments in progenetic Raphiophoridae, and up to 30 in Seleneceme (Alsataspididae), with long, narrow adaxial pleurae. Pygidium: wide, typically triangular, narrow axis extending to posterior margin, border strongly declined, doublure very narrow. Other: Asaphoid protaspis shows common ancestry; Raphiophorus is the only Trinucleioid (indeed the only representative of the order Asaphida) that continues beyond the Ordovician-Silurian boundary. Families: Alsataspididae, Dionididae, Orometopidae, Raphiophoridae, Trinucleidae, Representative Genera: Ampyxina, Bergamia, Cnemidopyge, Cryptolithus, Dionide, Hapalopleura, Orometopus, Protolloydolithus, Raphiophorus, Seleneceme, Trinucleus. Other notes: Trincleioid trilobites are highly specialized, but fall within the Asaphida via their asaphoid protaspides and the presence of the ventral median suture in at least the more primitive representatives of the superfamily. |
| Anomocaroidea | Asaphoidea | Cyclopygoidea | Trinucleioidea | Dikelokephaloidea | Remopleuridoidea |
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Walking Trilobite animation ©2000
by S. M. Gon III
All line drawings this page ©1999 - 2008 by
S.
M. Gon III