Ancient Antarctica: the early evolutionary history of<i>Nothofagus</i>
Bárbara Vento, Federico Agraín, Griselda Puebla
Abstract
ABSTRACTThe genus Nothofagus (southern beech) has an extensive fossil record and extant species exclusively distributed in the Southern Hemisphere. It is divided into four subgenera widespread across eastern Australasia and southern South America. The origin and evolution among closely related species remain an important question in palaeontology. The goal of this work is to reconstruct the biogeography of Nothofagus incorporating a complete leaf fossil dataset to better understand its origin, diversification, and colonisation history. The most ancient fossil leaves were discovered in Antarctica and are herein included for the first time into phylogenetic and biogeographic analyses. We employed statistical biogeographic methods implemented in BioGeoBEARS to estimate ancestral areas. The results support a high probability that the ancient ancestor of Nothofagus may have originated in Antarctica during the Late Cretaceous which is also supported by the fossil pollen record found in the Antarctic Peninsula. Subgenera Fuscospora and Lophozonia resulted in the most ancient clades, while the subgenera Nothofagus and Brassospora evolved later (Palaeogene). Our model supports that subgenera divergences were characterised by both dispersal and vicariance events from the Late Cretaceous to the early–middle Eocene.KEYWORDS: Nothofagaceaefossilleavesphylogenybiogeographysouthern beech AcknowledgmentsThis work was funded by CONICET (National Council of Science and Technology, Argentina). FAA is gratefully to the additional support for the completion of this study provided by ANPCyT (Agencia Nacional de Promoción Científica y Técnica, Argentina) PICT-2019-03121, and to CONICET PIP 2021–2023 (11220200102638CO). We would like to express a special acknowledgement to M. Prámparo for the valuable comments and suggestions made on the final version of the manuscript. We also thank the Willi Hennig Society for making the TNT program freely available. We kindly thank the comments of the anonymous reviewers that improved our work.Disclosure statementNo potential conflict of interest was reported by the author(s).Supplementary materialSupplemental data for this article can be accessed online at https://doi.org/10.1080/08912963.2022.2150549.