An exquisitely preserved filmy fern (Hymenophyllaceae) from the Early Cretaceous of Mongolia

Fabiany Herrera*, Robbin C. Moran, Gongle Shi, Niiden Ichinnorov, Masamichi Takahashi, Peter R. Crane, Patrick S. Herendeen

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

6 Scopus citations

Abstract

PREMISE OF THE STUDY: Hymenophyllaceae (“filmy ferns”) are a widely distributed group of predominantly tropical, epiphytic ferns that also include some temperate and terrestrial species. Hymenophyllaceae are one of the earliest-diverging lineages within leptosporangiate ferns, but their fossil record is sparse, most likely because of their low fossilization potential and commonly poor preservation of their delicate, membranaceous fronds. A new species of unequivocal fossil Hymenophyllaceae, Hymenophyllum iwatsukii sp. nov., is described from the Early Cretaceous of Mongolia based on abundant and exceptionally well-preserved material. METHODS: Bulk lignite samples collected from Tevshiin Govi and Tugrug localities in Mongolia, were disaggregated in water, cleaned with hydrochloric and hydrofluoric acids, washed, and dried in air. Fossils were examined and compared to material of extant Hymenophyllaceae using LM and SEM. KEY RESULTS: The fossil fern specimens are assigned to the Hymenophyllaceae based on their membranaceous laminae with marginal sori that have sessile to short-stalked sporangia with oblique, complete annuli, and trilete, tetrahedral-globose spores. Within the family, the fossil material is assigned to the extant genus Hymenophyllum on the basis of bivalvate indusia and short, included receptacles. CONCLUSIONS: Hymenophyllum iwatsukii was likely an epiphyte based on the sedimentary environment in which the fossils are preserved, the associated fossil flora, and the growth habit of extant species of Hymenophyllum. The new fossil species underlines the extent to which morphological characters in Hymenophyllum have been conserved despite significant tectonic, climatic, ecological, and floristic changes since the Early Cretaceous.

Original languageEnglish (US)
Pages (from-to)1370-1381
Number of pages12
JournalAmerican Journal of Botany
Volume104
Issue number9
DOIs
StatePublished - 2017

Keywords

  • Albian
  • Aptian
  • Epiphytic
  • Fern
  • Fossil
  • Hymenophyllum
  • Morphology

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Genetics
  • Plant Science

Fingerprint Dive into the research topics of 'An exquisitely preserved filmy fern (Hymenophyllaceae) from the Early Cretaceous of Mongolia'. Together they form a unique fingerprint.

Cite this