First occurrence and biogeographical significance of the operculate tetracoral Goniophyllum from the Wenlock (Silurian) of Baillie-Hamilton Island, Canadian Arctic

Opercula of the Silurian tetracoral genera Goniophyllum and Rhizophyllum are described from early Wenlock (Sheinwoodian) strata of the Cape Phillips Formation, Baillie-Hamilton Island, Canadian Arctic. This is the first record of Goniophyllum in northern Laurentia, emphasising previously recognised faunal connections of this region with Baltica and Avalonia. As the opercula of Goniophyllum belong mostly to very early juveniles, which have not previously been documented, specific identification is impossible.