Palaeoscenidiidae (Radiolaria) From The Lower Silurian Of The Cape Phillips Formation, Cornwallis Island, Nunavut, Canada

Spicular radiolarians of the family Palaeoscenidiidae were recovered from the Llandovery to lower Wenlock of the Cape Phillips Formation, Nunavut, Canada. Several changes are made to the classification of these radiolarians. Goodbodium rarispinosum was previously placed with Palaeoscenidium. Insolitignum is emended to allow for additional apical rays. Insolitignum cancellatum includes species which were previously assigned to Palaeoscenidium, Palaeotripus, and Palaeoephippium, owing to the variable development of one ray. Insolitignum peranima is synonymized with I. dissimile. Palaeodecaradium apertum was previously placed with Palaeoscenidium; Palaeotripus nudus is considered a synonym of P. apertum. Palaeoephippium is rediagnosed based on the branching of the basal rays; the new diagnosis also allows for more than six rays and in orientations other than originally diagnosed. Palaeoephippium aranea is a junior synonym of P. bifurcum. Palaeoephippium reteforme and P. ramipendentes are synonymized with P. radices. Palaeotripus monospinosum is synonymized with Palaeoephippium spinosum. One new species, Palaeodecaradium gordoni, is described. It possesses six rays; the apical rays are long and curved. The basal rays bear spinules on their lateral margins.