Upper Ordovician Beaverfoot Formation, demosponges


An unusually large specimen of the rare digitate to bladed Aulocopella winnipegensis Rauff and three relatively normal sized specimens of ashtray-shaped Hudsonospongia? sp. constitute the first record of demosponges from the Upper Ordovician Beaverfoot Formation in southeastern British Columbia and the first record of these taxa from western Canada. Gross form and canal structure are well preserved, but dolomitization and (or) coarse microsphaeroidal silicification have obliterated spicules and other structural details. We interpret these sponges as epifaunal recliners, without means of attachment to the substrate, a life mode rarely encountered in the modern sponge biota.

Original Publication Citation

Rigby, J. Keith, and Paul A. Johnston. "An Unusually Large Aulocopella Winnipegensis and Associated Demosponges from the Upper Ordovician Beaverfoot Formation, Southeastern British Columbia." Canadian Journal of Earth Sciences = Revue Canadienne des Sciences de la Terre 41.8 (24): 939-47.

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Peer-Reviewed Article

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National Research Council Canada




Physical and Mathematical Sciences


Geological Sciences

Archaeoscyphia pulchra.pdf (421 kB)
A few specimens of the ornate anthaspidellid demosponge, Archaeoscyphia pulchra (Bassler), have been collected from the Lower Ordovician Outram Formation or Skoki Formation, from a saddle at the head of South Rice Brook in northeastern British Columbia. This is the first report of the flanged-appearing annulate, steeply obconical sponge in western Canada, although it has been reported from the Mingan Islands of Quebec and was initially described from Nevada, in the western United States. The taxon has also been reported as other species of Archaeoscyphia from Ordovician rocks of Missouri and from the San Juan region of Argentina.

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