Evolutionary Processes in the fossil record of Patagonia



2146 Snee Hall


At 4:30 pm, there will be a reception with snacks and refreshments following the seminar in Snee 2146 for faculty, staff, and students to meet Dr. Gandolfo.

Alejandra Gandolfo  
Associate Professor; LH Bailey Hortorium, Plant Biology Section School of Integrative Plant Science | College of Agriculture and Life sciences


Evolutionary biology, paleobotany; plant anatomy and morphology; plant evolution; paleoenvironments; paleoclimates

Title: Evolutionary Processes in the fossil record of Patagonia

Patagonia is the southernmost area of South America comprising the landmasses between 37° and 55° S. This region has an intense geological history from the beginning of the breakup of Gondwana, accentuated during the Cenozoic when it separated from Antarctica until the completion of the rising of the Andes. Major geotectonic and climatic changes that affected Patagonia include its separation from Antarctica, the establishment of the Circumpolar and Humboldt Currents, the Pacific and Atlantic ingressions, the uplift of the Andes, and the development of the “Patagonian Arid Diagonal”. This complex tectonic activity coupled with intense climatic changes turned Patagonia into a natural floristic laboratory in which examples of biogeographic and evolutionary processes were documented by the fossil record. Research carry out on fossils from Patagonian formations that range from the Upper Cretaceous (~80 mya) to the end of the Paleogene (~23 mya) coupled with those from the Antarctic Peninsula is providing critical data for understanding the origin and evolution of floras in the Southern Hemisphere. In this contribution, I will present iconic examples of these evolutionary processes that occurred in Patagonia in relation to the geological and climatic variables. Examples of evolutionary processes comprise 1- the extinction of Casuarianaceae, Eucalyptus, and Agathis; 2- the retraction of Arecaceae and Ulmaceae; 3- the diversification of Nothofagus; 4- the typical disjunction of Winteraceae, Cunoniaceae, and Araucaria; 5- the expansion of the grass steppe, and 6- the speciation of Proteaceae.



Carolyn Headlam - ch339@cornell.edu