grade basal to the derived species in Ulmus subgenus Oreoptelea. The morphology of the leaf edges and bases was noted to be similar to fossils found in Paleocene rocks of Ellesmere Island, late Paleocene to Early Eocene rocks of Spitsbergen, and Paleocene rocks of North-east China. The species Early Eocene Ulmus fushunensis described in 2010 from the Jijuntun Formation of Liaoning Province, China, displays noted similarities to U. okanaganensis as well. Description The studied leaves of U. okanaganensis are split into three major morphotypes, leaves from sucker-shoot stems of the trees, leaves from the "elongation" or short branches, and leaves from the reproductive shoots. The sucker-shoot leaves range up to in length. The short, thick petiole is bracketed by uneven lobes of the leaf base, with one lobe typically being distinctly larger than the other. The leaves have a pinnate vein structure, with the primary vein having between twelve and fourteen secondary veins branching from it at decreasingly sharp angles from apex to base of the leaf. The secondary veins and the exterior branches off the secondaries terminate in teeth along the leaf margins. The leaves have compound teeth, each of the large teeth on having a smaller tooth located basally between it and the next large tooth. All the teeth typically have convex sides that terminate at blunt tooth tips, though occasional teeth have straight or concave sides. In the elongation shoot leaves, the petioles are short and thick, though shorter and thinner than those of the sucker-shoot leaves. Similarly the leaves are smaller, ranging up to long, and the bases are typically only slightly asymmetrical. They have a cordate to auriculate leaf blade base and an acute leaf tip. The primary vein ranges between fully straight and slightly curved as it progresses from base to tip. There are a similar number of secondary veins to those in the other two leaf types, with a usual minimum of eleven pairs; however, the angle of the secondaries to the primary increases towards the base rather than decreasing as seen in the sucker-shoot leaves. The short-shoot leaves are range between and long, much like the length of the elongation shoot leaves. However the elongation shoot leaves are up to wide while short shoot leaves are wide. There are between eight and fourteen secondary veins, with up to three veins branching off the undersides of each secondary close to the leaf base,