Affiliations 

  • 1 Department of Biology and Geobio-Center, University of Munich (LMU), Munich, Germany
  • 2 Mittlere Letten 11, Herdwangen-Schönach, Germany
  • 3 Swedish Museum of Natural History, Stockholm, Sweden
  • 4 Birbal Sahni Institute of Palaeobotany, Lucknow, India
  • 5 Botany Department, Eszterházy University, Eger, Hungary
  • 6 Division of Invertebrate Zoology, American Museum of Natural History, New York, New York, United States of America
  • 7 Instituto de Botânica, São Paulo, Brazil
  • 8 Royal Botanic Gardens and Domain Trust, Sydney, Australia
  • 9 Department of Geobiology, University of Göttingen, Göttingen, Germany
PLoS One, 2016;11(5):e0156301.
PMID: 27244582 DOI: 10.1371/journal.pone.0156301

Abstract

Cambay amber originates from the warmest period of the Eocene, which is also well known for the appearance of early angiosperm-dominated megathermal forests. The humid climate of these forests may have triggered the evolution of epiphytic lineages of bryophytes; however, early Eocene fossils of bryophytes are rare. Here, we present evidence for lejeuneoid liverworts and pleurocarpous mosses in Cambay amber. The preserved morphology of the moss fossil is inconclusive for a detailed taxonomic treatment. The liverwort fossil is, however, distinctive; its zig-zagged stems, suberect complicate-bilobed leaves, large leaf lobules, and small, deeply bifid underleaves suggest a member of Lejeuneaceae subtribe Lejeuneinae (Harpalejeunea, Lejeunea, Microlejeunea). We tested alternative classification possibilities by conducting divergence time estimates based on DNA sequence variation of Lejeuneinae using the age of the fossil for corresponding age constraints. Consideration of the fossil as a stem group member of Microlejeunea or Lejeunea resulted in an Eocene to Late Cretaceous age of the Lejeuneinae crown group. This reconstruction is in good accordance with published divergence time estimates generated without the newly presented fossil evidence. Balancing available evidence, we describe the liverwort fossil as the extinct species Microlejeunea nyiahae, representing the oldest crown group fossil of Lejeuneaceae.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.