A new species of the genus Birisia (Dicksoniaceae) from the lower–middle Albian deposits of Southern Primorye, Far East of Russia

Abstract

A new fern Birisia mandshurica, sp. nov. (Dicksoniaceae) from the lower–middle Albian Frentsevka Formation of southern Primorye, Far East of Russia is described. This species is characterized by short-creeping rhizomes with closely spaced stipes and bipinnate fronds with narrow linear pinnules. A reconstruction of B. mandshurica is proposed. It comes from the autochthonous locality of ferns and herbaceous angiosperms and was a part of pioneer open community, which occupied low flat plains between river channels. Revision of ferns, described as Acanthopteris gothanii Sze from China, shows, that these ferns belongs to Birisia alata (Prynada) Samylina. The name Acanthopteris Sze should be abandoned, due to absence of spore-bearing pinnules and poor preservation of sterile pinnules in type specimens. Based on Chinese and Russian material of good preservation, we provide emended diagnoses of the genus Birisia Samylina and its type species B. alata. Re-examination of various species of the genus Birisia revealed that this genus was widely distributed in the Cretaceous floras (from the Barremian to the Coniacian) of Eastern Siberia, New Siberian Islands, North-East and Far East of Russia, China, Japan, Alaska and Western Canada. B. alata is the most widespread species.

Angiosperm diversification in the Early Cretaceous of Primorye, Far East of Russia

“…The angiosperm remains are accompanied by the ferns Onychiopsis psilotoides (C.stoKes et weBB) ward and Birisia mandshurica Golovn., GraBovsKiy et Zolina, which are represented by almost entire young plants (Golovneva et al 2020). According to environmental reconstruction, Onychiopsis m.yoKoy.…”