Brachyphyllum liaoningense sp. nov. from the Upper Jurassic of Northeast China

Abstract

Fossil conifer twigs and foliage referred to Brachyphyllum liaoningense sp. nov. were collected from the Tuchengzi Formation of Beipiao Basin, Liaoning Province, Northeast China. The leaves are arranged spirally on twigs, with a basal cushion tapering into a small free part. The length of the free part is little less than the width. Stomata exist on both adaxial and abaxial cuticles, but more on the abaxial side. The stomata are rounded or elliptic in form and arranged in longitudinal files in the abaxial cuticle, the epidermal cells between the stomatal files are elongated rectangular or in strip-form. The guard cells are sunken. The subsidiary cells are monocyclic, 5-7 in number, lack encircling cells. A few stomata are scattered on the adaxial cuticle, which are similar to those of the abaxial cuticle except that they have encircling cells. It is presumed that the subsidiary cells of Brachyphyllum show a tendency of increasing in number from Jurassic to the Early Cretaceous.