Order Phacopida:

Suborder Phacopina

This was the last of the three suborders to be identified by Struve in the 1930's. The cephalon contains proparian sutures. The schizochroal eyes of Phacopina are generally well developed. The glabella expands forward and sometimes has genal spines, but these are usually lacking. It has no rostral plate. The thorax typically has 10-11 segments with a furrowed pleurae and tip either rounded, angular or spinose. The pygidium is usually smaller than the cephalon and is smooth or spinose. The diagram below shows the main features of this suborder. The photographs below are a selection of specimens of this suborder.

Suborder Phacopina  Superfamily Phacopacea Family Phacopidae Subfamily Phacopinae Genus Reedops Species cephalotes

Reedops cephalotes with main features of this suborder labelled

Phacops sp. showing slight enrollment of the lower thorax and pygidium	Phacops sp. showing pygidium and deep axial furrows	Dalmanites sp. cephalon showing forward expanding glabella
Dalmanites sp. enrolled, showing cephalon and eyes to either side and pygidium tucking under the cephalon	Dalmanites sp. enrolled, view from top showing thoracic segments interlocking	Dalmanites sp. from the Silurian

Dalmanites limilurus with well developed genal and pygidial spines and well developed eyes (Photograph from www.wikipedia.org)

• Introduction
• Characters/Anatomy
• Major Suborders
  • Suborder Calymenina
  • Suborder Cheiruina
• Fossil Record
• Modern Forms
• Geological Timescale
• Glossary
• Literature and web links

Author: Sarah Vinnell
Last updated: 21/11/05
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