EXPANDING THE FOSSIL RECORD OF LATE CRETACEOUS ANTARCTIC FORESTS: BIODIVERSITY AND ECOLOGY INFERRED FROM ANATOMICALLY PRESERVED WOODS

In the Late Cretaceous, the Antarctic Peninsula hosted a rainforest ecosystem of a type that has no direct modern analogue. Understanding the biodiversity and ecophysiology of these Antarctic Cretaceous plants can provide valuable information on the history of different biomes, as well as how plants functioned in these unique austral polar conditions, characterized by above-freezing temperatures and the annual cycles of light and darkness present at extreme latitudes. Analysis of fossil woods from the Antarctic Peninsula will contribute important data to answer these questions. Angiosperm and gymnosperm samples collected from James Ross Island (Santa Marta Formation), Vega Island (López de Bertodano Formation), and Seymour Island (López de Bertodano Formation) are being identified. Angiosperm samples span at least three distinct morphotaxa, representing new and previously identified species in the families Nothofagaceae and Schisandraceae (Illiciaceae). In addition, traits including growth ring analysis, vessel diameter, and presence/absence of septate fibers, large rays, and semi-ring-porous wood were collected to evaluate the climate relationship of the assemblages. By tracing lineages through space and time, these fossil woods can inform us about the plant biodiversity of these extinct forests and how they responded to their unique environment.