First record of Rhaphidopteris (Gymnospermae) from the Lower Jurassic of the Junggar Basin, Xinjiang, NW China

Abstract

Abstract Newly discovered foliage of Rhaphidopteri s zhouii sp. nov. from the Lower Jurassic Sangonghe Formation at the Haojiagou section in the Junggar Basin of Xinjiang, northwestern China, is investigated based on morphological characters and cuticular structure. The new species has anisotomically divided leaves and linear ultimate segments with a single vein; amphistomatic cuticle, with epidermal cells that are similar both on the upper and lower surfaces but more regular on the upper surface; stomata that are distributed densely on the lower cuticle and sparsely and confined to two bands near the lateral margin on the upper cuticle; and anomocytic stomata that are longitudinally oriented with four to six subsidiary cells of irregular shape and size. This is the first report of the genus Rhaphidopteris from Xinjiang. The gross morphology and epidermal characters of the new species improves our understanding of the morpho-heterogenus Rhaphidopteri s.