Ancient noeggerathialean reveals the seed plant sister group diversified alongside the primary seed plant radiation

Author(s)
Jun Wang, Jason Hilton, Hermann W. Pfefferkorn, Shijun Wang, Yi Zhang, Jiri Bek, Josef Pšenička, Leyla J. Seyfullah, David Dilcher
Abstract

Noeggerathiales are enigmatic plants that existed during Carboniferous and Permian times, ∼323 to 252 Mya. Although their morphology, diversity, and distribution are well known, their systematic affinity remained enigmatic because their anatomy was unknown. Here, we report from a 298-My-old volcanic ash deposit, an in situ, complete, anatomically preserved noeggerathialean. The plant resolves the group’s affinity and places it in a key evolutionary position within the seed plant sister group. Paratingia wuhaia sp. nov. is a small tree producing gymnospermous wood with a crown of pinnate, compound megaphyllous leaves and fertile shoots each with Ω-shaped vascular bundles. The heterosporous (containing both microspores and megaspores), bisporangiate fertile shoots appear cylindrical and cone-like, but their bilateral vasculature demonstrates that they are complex, three-dimensional sporophylls, representing leaf homologs that are unique to Noeggerathiales. The combination of heterospory and gymnospermous wood confirms that Paratingia, and thus the Noeggerathiales, are progymnosperms. Progymnosperms constitute the seed plant stem group, and Paratingia extends their range 60 My, to the end of the Permian. Cladistic analysis resolves the position of the Noeggerathiales as the most derived members of a heterosporous progymnosperm clade that are the seed plant sister group, altering our understanding of the relationships within the seed plant stem lineage and the transition from pteridophytic spore-based reproduction to the seed. Permian Noeggerathiales show that the heterosporous progymnosperm sister group to seed plants diversified alongside the primary radiation of seed plants for ∼110 My, independently evolving sophisticated cone-like fertile organs from modified leaves.

Organisation(s)
Department of Palaeontology
External organisation(s)
Chinese Academy of Sciences (CAS), University of the Chinese Academy of Sciences, University of Birmingham, University of Pennsylvania, Shenyang Normal University, Czech Academy of Sciences, Museum of West Bohemia, Indiana University Bloomington
Journal
Proceedings of the National Academy of Sciences
Volume
118
Pages
1-7
No. of pages
7
DOI
https://doi.org/10.1073/pnas.2013442118
Publication date
03-2021
Peer reviewed
Yes
Austrian Fields of Science 2012
105117 Palaeobotany
Keywords
ASJC Scopus subject areas
General
Portal url
https://ucrisportal.univie.ac.at/en/publications/e7d4f356-eb46-42bd-aab4-5ae9c9cce52e