Protocedroxylon macgregorii sp. nov., from Jurassic strata of British Columbia, Canada, is the first reported occurrence of this genus in North America. Protocedroxylon macgregorii combines the tracheal pitting of the araucarians with the crossfield pitting of modern genera of the Abietineae. This species is similar to the type species Protocedroxylon araucarioides. They differ in that P. araucarioides has tangential pitting, tracheid septations, and entirely uniseriate rays. These features are lacking in P. macgregorii with the exception of the rays, which are partially biseriate in the latter species. Protocedroxylon macgregorii has traumatic resin canals or cysts that have not been reported in P. araucarioides.
Medlyn, David A. and Tidwell, William D.
"New species of Protocedroxylon from the Upper Jurassic of British Columbia, Canada,"
Great Basin Naturalist: Vol. 46
, Article 11.
Available at: https://scholarsarchive.byu.edu/gbn/vol46/iss3/11