extinct stem-arthropod species found in Cambrian fossil deposits

Opabinia is a fossil animal found in Cambrian fossil deposits. Its sole species, Opabinia regalis, is known from the Middle Cambrian Burgess Shale of British Columbia. The discoverer of Opabinia,Charles Doolittle Walcott, named it after a local mountain, Opabin Peak in the Canadian Rockies. Thirty specimens of Opabinia are known and each ranges in size from 40 to 70 mm. The most intriguing feature of Opabinia are its five eyes found on the dorsal surface of the head. These eyes were used to search for food. Because of its flexible body it is not known whether Opabinia was pelagic or benthic.

Temporal range: Middle Cambrian
Opabinia BW.jpg
Scientific classification
O. regalis
Binomial name
Opabinia regalis


  • Bergström, J. (1986). Opabinia and Anomalocaris, unique Cambrian arthropods. Lethaia 19, 241–246.
  • Bergström, J. (1987). The Cambrian Opabinia and Anomalocaris. Lethaia 20, 187–188.
  • Briggs, D. E. G. & Whittington, H. B. (1987). The affinities of the Cambrian animals Anomalocaris and Opabinia. Lethaia 20, 185–186.
  • Budd, G. E. (1996). The morphology of Opabinia regalis and the reconstruction of the arthropod stem-group. Lethaia 29, 1–14.
  • Whittington, H. B. (1975). The enigmatic animal Opabinia regalis, Middle Cambrian Burgess Shale, British Columbia. Philosophical Transactions of the Royal Society of London B 271, 1–43.
  • Zhang, X. & Briggs, D. E. G. (2007). The nature and significance of the appendages of Opabinia from the Middle Cambrian Burgess Shale. Lethaia 40, 161–173.