Chamaecyparis eureka

Chamaecyparis eureka is an extinct species of conifer in the family Cupressaceae. It is known from fossil foliage found in the Buchanan Lake Formation deposits, dated to the middle Eocene Lutetian stage (48 to 41 million years ago), from western Axel Heiberg Island, located in the Arctic Ocean in the Qikiqtaaluk Region, Nunavut, Canada.C. eureka is the oldest confirmed member of the genus Chamaecyparis, which includes five to six living species, depending on circumscription, which are native to Eastern Asia, Japan, and North America.

Description of the new species by M. E. A. Kotyk, James Basinger, and Elisabeth McIlver was based on the study of more than 850 twigs and 650 seed cone specimens; the holotype specimen, number "USPC-6357", and the five paratypes are housed in the University of Saskatchewan Paleobotanical Collection, Saskatoon, Saskatchewan, Canada. They published their 2003 type description of the species in the Canadian Journal of Botany volume number 81. and named the species eureka to reflect the type locality placement in the Eureka Sound group, Axel Heiberg Island.