J Syst Evol ›› 2019, Vol. 57 ›› Issue (2): 142-152.DOI: 10.1111/jse.12424

• Research Articles • Previous Articles     Next Articles

Early Oligocene Calocedrus (Cupressaceae) from the Maoming Basin, South China, and its paleogeographic and paleoclimatic implications

Yan Wu1,2, Jian-Hua Jin1, Nan Li3, Hui-Min He3, Ting Chen2*, and Xiao-Yan Liu1,2*   

  1. 1State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources, and School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
    2Shenzhen Key Laboratory of Southern Subtropical Plant Diversity, Shenzhen 518004, China
    3National Cycad Conservation Center, Fairylake Botanical Garden, Shenzhen & Chinese Academy of Science, Shenzhen 518004, China
  • Received:2018-01-24 Accepted:2018-05-06 Online:2018-05-17 Published:2019-03-01

Abstract: The genus Calocedrus Kurz is characterized by flattened branches covered with decussate and dimorphic leaves. In this study, we describe fossil foliage of Calocedrus discovered in the Shangcun Formation (early Oligocene) of the Maoming Basin, South China. The fossils have wedge‐shaped branchlet segments and scale‐like strongly dimorphic leaves, similar to the fossil species Calocedrus lantenoisi (Laurent) Tao. There have been no detailed studies of the morphological features and cuticle structures of C. lantenoisi. Therefore, a newly emended diagnosis of the species C. lantenoisi is given based on a detailed study of leaf morphology and cuticular characters exhibited by the Maoming fossils. This is one of the earliest fossil records of Calocedrus in the world, providing additional evidence for the early biogeographic history of this genus and supporting the inference that eastern Asian Calocedrus is primitive among all the living species. The extant species of Calocedrus are mainly distributed in mountainous regions. On the basis of the “nearest living relative” analysis, we propose that the Maoming Basin was adjacent to a mountainous region during the early Oligocene.

Key words: Calocedrus, Cupressaceae, Early Oligocene, Maoming Basin, paleoclimate, paleogeography