Ancient Antarctica: the early evolutionary history of Nothofagus

VENTO, BARBARA; AGRAIN, FEDERICO; PUEBLA, GRISELDA

Historical biology

Taylor and Francis

Año: 2022

0891-2963

Thegenus Nothofagus (southern beech) hasan extensive fossil record and extant species exclusively distributed in theSouthern Hemisphere. It is divided into four subgenera widespread across easternAustralasia and southern South America. The origin and evolution among closelyrelated species remain an important question in paleontology. The goal of thiswork is to reconstruct the biogeography of Nothofagusincorporating a complete leaf fossil dataset to better understand its origin,diversification, and colonization history. The most ancient fossil leaves werediscovered in Antarctica and are herein included for the first time intophylogenetic and biogeographic analyses. We employed statistical biogeographicmethods implemented in BioGeoBEARS to estimate ancestral areas. The resultssupport a high probability that the ancient ancestor of Nothofagus may have originated in Antarctica during the LateCretaceous which is also supported by the fossil pollen record found in the AntarcticPeninsula. Subgenera Fuscospora and Lophozonia resulted in the most ancientclades, while the subgenera Nothofagus andBrassospora evolved later(Paleogene). Our model supports that subgenera divergences were characterizedby both dispersal and vicariance events from the Late Cretaceous to theearly–middle Eocene.