Phylum: Arthropoda
Class: Trilobita
Order: Lichida (Fortey and Chatterton, 1988)
Cincinnatian Families: Lichidae, Odontopleuridae

Geologic Range
Late Ordovician-Late Devonian

Common Paleoecology
Fast-moving, low-level epifaunal carnivore.

Characteristics of the Order

  • Typically spiny with densely granulate or tuberculate exoskeletons.
  • Typically 8-13 , spine-tipped, thoracic segments.
  • Glabella broad, large, extending to anterior border.
  • Eyes typically present, holochroal, usually smaller.

Published Descriptions

Treatise on Invertebrate Paleontology (1959):

  • Medium sized to exceptionally large trilobites chiefly characterized by distinctive cephalic and pygidial features. Glabella broad, extending to anterior border, which may be ill-defined; with pair of lateral glabellar furrows longitudinally elongated; lateral glabellar and occipital lobes tend to fuse with one another and with other parts of the cranidium; facial sutures opisthoparian. Pygidium large, pleural regions usually flattened and composed of 3 pairs of pleurae that commonly exhibit leaf-like or strongly spinose form. Dorsal surface almost invariably tuberculate.