J Syst Evol ›› 2019, Vol. 57 ›› Issue (4): 305-328.DOI: 10.1111/jse.12501

• Research Articles • Previous Articles     Next Articles

How diverse were ferns in the Baltic amber forest?

Eva-Maria Sadowski1,2*, Leyla J. Seyfullah3, Ledis Regalado4, Laura E. Skadell1, Alexander Gehler5, Carsten Gröhn6, Christel Hoffeins6, Hans Werner Hoffeins6, Christian Neumann2, Harald Schneider7, and Alexander R. Schmidt1*   

  1. 1Department of Geobiology, University of Göttingen, Goldschmidtstraße 3, 37077 Göttingen, Germany 
    2Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstraße 43, 10115 Berlin, Germany
    3Department of Palaeontology, University of Vienna, Althanstraße 14, 1090 Vienna, Austria
    4Institute of Ecology and Systematics, Varona 11835, 11900 Havana, Cuba
    5Geoscience Museum, University of Göttingen, Goldschmidtstraße 3, 37077 Göttingen, Germany
    6Amber Study Group, c/o Geological‐Palaeontological Institute and Museum (CeNak) of the University of Hamburg, Bundesstraße 55, 20146 Hamburg, Germany
    7Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Menglun 666303, Yunnan, China
  • Received:2019-02-01 Accepted:2019-04-17 Online:2019-08-09 Published:2019-07-01


Diverse temperate forest types and a high atmospheric humidity have recently been suggested for the Eocene source area of Baltic amber. However, ferns are astonishingly rare as inclusions in this amber, which is in contrast to other seed‐free land plants, fungi, and lichens. Moreover, the identities of some of the few described putative fern taxa are dubious, and some fossils were even assigned to the Paleozoic seed fern genera Alethopteris, Pecopteris and to the form genus Sphenopteris containing Paleozoic and Mesozoic fern‐like leaf fossils. Here, we review previously described fern inclusions from Baltic amber and identify further fern‐like leaf inclusions as belonging to the extant angiosperm genus Comptonia (sweet ferns, Myricaceae). We conclude that only one taxon, Matonia striata (Matoniaceae), can with confidence be identified as a Polypodiopsida representative. Although “Pecopterishumboldtiana is so far only known as sterile foliage, its leaf morphology strongly suggests that also this taxon belongs to the Polypodiopsida rather than to any other tracheophyte lineage. We propose accommodating “Pecopterishumboldtiana in the new genus Berendtiopteris. “Alethopterisserrata and “Sphenopteris” phyllocladoides are not to be regarded as evidence of ferns from Baltic amber. Reinvestigation of the holotypes of these two taxa did not reveal to which tracheophyte lineages these fossils belong. We suggest that the scarcity of fern remains from Baltic amber may reflect both a relatively low fern diversity in the source area of the fossil resin, and an absence or rarity of epiphytic and climbing ferns as observed in modern temperate forest ecosystems.

Key words: Alethopteris serrata, Baltic amber forest, Berendtiopteris, Comptonia, Eocene, Matonia striata, Matoniaceae, Myricaceae, Paleogene, Pecopteris humboldtiana, Sphenopteris phyllocladoides