Compare the pictorial approach above with the descriptive narrative below:
Introduction: typically small trilobites, recently separated from Ptychopariida; protaspid growth stages of the two orders are similar, but protaspides of Proetida show early development of preglabellar field (a meraspid development in Ptychopariida); one of the Libriostomate orders (natant hypostome or derived therefrom); exoskeleton sometimes with pits or small tubercles. The last of the trilobites was of this order (Phillipsiidae).
Cephalon: opisthoparian sutures; glabella large, vaulted, well-defined, typically narrowing forwards, typically 4 pairs of glabellar furrows with posterior-most pair longest and deepest, those anterior shorter and fainter; eyes, usually present, holochroal, often large, convex; rostral plate narrow and backward tapering; long hypostome, most species natant, but some secondarily conterminant (e.g., late Proetidae & Bathyuridae); typically with genal spines.
Thorax: 8 – 22 (typically 10) segments, tips variable, blunt to long-spined.
Pygidium: micropygous to subisopygous, often spineless, and usually with 4 – 10+ distinct pleural furrows.
Occurrence: Ordovician (Tremadoc) to Permian (Tartarian)
Suborders: None (or nominate Proetina)
Superfamilies: Proetoidea, Aulacopleuroidea, Bathyuroidea
PROETIDA includes three Superfamilies:
(click on the images to view the pictorial guides)
Return to Proetida Fact Sheet
Walking Trilobite animation ©2000 by S. M. Gon III