According to Hagadorn et al., Tirasiana coniformis might be a synonym of Aspidella terranovica Billings, 1872.
Lit.:
MacGabhann, B. A. (2007) Discoidal fossils of the Ediacaran biota: a review of current understanding. Geological Society, London, Special Publications, 286, 297-313, 1 January 2007, https://doi.org/10.1144/SP286.21