Tsukada leaf fossils have been identified from two locations in Western North America, the 49 million year old Klondike Mountain Formation near Republic, Washington[1] and at the One Mile Creek locality near Princeton, British Columbia.

Additionally the counterpart to specimen UW 39187 was preserved in the University of California Museum of Paleontology collection as UCMP 9302.

Working from these specimens, collected in the Republic, Washington area in the early 1980s, the fossils were studied by Jack A. Wolfe of the University of California and Wesley C. Wehr of the Burke Museum.

[1] They published their 1987 type description for the genus and species in a United States Geological Survey monograph on the North Eastern Washington dicot fossils.

They suggested that if Tsukada were of "low grade leaf morphology" to Davidia then the two genera might have been closer in relation to Escalloniaceae than to the Cornales.

[1] However molecular phylogeny in the years after Wolfe and Wehrs description of Tsukada has shown Davidia to be a member of the Cornales, and placed in to the family Nyssaceae.