Percid remains from Pliocene deposits on Ellesmere Island, Arctic Canada, are identified as a species of Sander, similar to the walleye and sauger of North America and the pike-perch of Europe and western Asia. They are named as a new species, Sander teneri. These remains are the most northerly percid elements found to date and suggest the palaeoenvironment was significantly warmer in the Pliocene than it is currently. The fossil remains show the presence in North America of the family Percidae as well as the genus Sander prior to the Pleistocene, indicating a previously proposed Pleistocene immigration from Europe or Asia can be discounted. These fossils contradict an earlier hypothesis that percids, in particular Sander, crossed from Eurasia to North America in the Pleistocene; instead, the fossils show percids were already in the area by the Pliocene.
Canadian Journal of Earth Sciences
Department of Biology

Murray, A.M. (Alison M.), Cumbaa, S.L. (Stephen L.), Harington, C.R. (C. Richard), Smith, G.R. (Gerald R.), & Rybczynski, N. (2009). Early Pliocene fish remains from Arctic Canada support a pre-Pleistocene dispersal of percids (Teleostei: Perciformes). Canadian Journal of Earth Sciences, 46(7), 557–570. doi:10.1139/E09-037