title: A Jurassic wood providing insights into the earliest step in Ginkgo wood evolution.
abstract: The fossil record of Ginkgo leaf and reproductive organs has been well dated to the Mid-Jurassic (170 Myr). However, the fossil wood record that can safely be assigned to Ginkgoales has not yet been reported from strata predating the late Early Cretaceous (ca. 100 Myr). Here, we report a new fossil wood from the Mid-Late Jurassic transition deposit (153-165 Myr) of northeastern China. The new fossil wood specimen displays several Ginkgo features, including inflated axial parenchyma and intrusive tracheid tips. Because it is only slightly younger than the oldest recorded Ginkgo reproductive organs (the Yima Formation, 170 Myr), this fossil wood very probably represents the oldest bona fide fossil Ginkgo wood and the missing ancestral form of Ginkgo wood evolution.
authors.affiliation: Chinese Academy of Geological Sciences, Beijing 100037, China.
authors.forename: Zikun
authors.initials: Z
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Palaeobiology &Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Yongdong
authors.initials: Y
authors.lastname: Wang
authors.affiliation: UMR 5023 of the CNRS and Université Lyon 1, 7 rue Dubois, F69622 Villeurbanne, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Philippe
authors.affiliation: Shenyang Institute of Geology and Mineral Resources, Shenyang, 110034, China.
authors.forename: Wu
authors.initials: W
authors.lastname: Zhang
authors.affiliation: College of Palaeontology, Shenyang Normal University, Shenyang, 110034, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Tian
authors.affiliation: Shenyang Institute of Geology and Mineral Resources, Shenyang, 110034, China.
authors.forename: Shaolin
authors.initials: S
authors.lastname: Zheng
mesh_terms: D005075:Biological Evolution; D002681:China; D005580:Fossils; D020441:Ginkgo biloba / Q000033:anatomy & histology* / Q000502:physiology*; D014934:Wood