title: Nystroemiaceae, a new family of Permian gymnosperms from China with an unusual combination of features.
abstract: Nystroemiaceae is proposed as a new family of gymnosperms from the Permian of Cathaysia that adds to the diversity of gymnosperms known from this critical time in seed plant evolution. This family is characterized by bifurcating and highly branched pinnate ovuliferous organs bearing bicornute ovules (seeds) and entire leaves with anastomozing veins that are born on complex and modern-looking branching systems with clear axillary branching. The reconstruction is based on numerous large specimens from two localities in North China, in which the different plant parts are attached to each other. The ovulate structures show some apparently plesiomorphic (primitive) character states more typical of early seed plants, whereas the leaves and branches show the clearly apomorphic (derived) character states of broad-leaved gymnosperms.
authors: LPS, Department of Palaeobotany and Palynology, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, People's Republic of China. jun.wang@nigpas.ac.cn
authors: Jun
authors: J
authors: Wang
authors: Hermann W
authors: HW
authors: Pfefferkorn
mesh_terms: D002681:China; D032462:Cycadopsida / Q000033:anatomy & histology* / Q000145:classification; D005580:Fossils; D010802:Phylogeny; D018515:Plant Leaves / Q000033:anatomy & histology