J Syst Evol ›› 2019, Vol. 57 ›› Issue (4): 329-338.DOI: 10.1111/jse.12514

• Research Articles • Previous Articles     Next Articles

Heinrichsia cheilanthoides gen. et sp. nov., a fossil fern in the family Pteridaceae (Polypodiales) from the Cretaceous amber forests of Myanmar

Ledis Regalado1*, Alexander R. Schmidt2, Patrick Müller3, Lisa Niedermeier4, Michael Krings5,6, and HaraldSchneider7   

  1. 1Institute of Ecology and Systematics, Varona 11835, 11900 Havana, Cuba
    2Department of Geobiology, University of Göttingen, Goldschmidtstraße 3, 37077 Göttingen, Germany
    3Amber Study Group, c/o Geological‐Palaeontological Museum (CeNak) of the University of Hamburg, Bundesstraße 55, 20146 Hamburg, Germany
    4School of Life Sciences, Technical University of Munich, Weihenstephan, Alte Akademie 8, 85354 Freising, Germany
    5SNSB‐Bavarian State Collection for Palaeontology and Geology, Richard‐Wagner‐Straße 10, 80333 Munich, Germany
    6Department of Earth and Environmental Sciences, Ludwig Maximilians University, Richard‐Wagner‐Straße 10, 80333 Munich, Germany
    7Center of Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Menglun 666303, Yunnan, China
  • Received:2019-02-22 Accepted:2019-05-13 Online:2019-07-29 Published:2019-07-01

Abstract:

Divergence time estimates suggest that most clades constituting the fern family Pteridaceae (Polypodiales) were in existence by the Early Cretaceous. However, fossil evidence to corroborate this remains exceedingly rare. Burmese amber is an important source of new information on the radiation of derived fern lineages during the Cretaceous Terrestrial Revolution. This study describes Heinrichsia cheilanthoides gen. et sp. nov., a fern with suggested affinities to Pteridaceae, based on fertile foliage portions preserved in Early Cretaceous (~100 Ma) amber from Myanmar. Heinrichsia cheilanthoides is characterized by a pinnate‐pinnatifid frond that bears apical, marginal sori protected by a pseudoindusium. Sporangia are of the polypod type and contain tetrahedral‐globose, trilete spores with a striate perine. This discovery provides a new calibration point to test and refine molecular clock‐based concepts of the evolutionary history of the Pteridaceae. Heinrichsia cheilanthoides further substantiates the suggestion that the Cretaceous forests of Myanmar were home to a rich fern flora.

Key words: Burmese amber, leptosporangiate ferns, Mesozoic, molecular clock estimate, seed-free land plants