Holotype specimen of Dennstaedtia christophelii （Image source：Kevmin， CC BY-SA 4.0 ） Age Paleogene（Ypresian） 50 Ma Taxonomy Kingdom: Plantae Class: Polypodiopsida Order: Polypodiales Family: Dennstaedtiaceae Genus: Dennstaedtia Species: Dennstaedtia christophelii Morphological description Dennstaedtia christophelii is currently known only from fossilized fronds, and thus the morphology of its roots, stems, and reproductive structures beyond the preserved sori remains unkno