Gonzalez, Cynthia C., Gandolfo, Maria A., Zamaloa, Maria C., Cúneo, Nestor R., Wilf, Peter, and Johnson, Kirk R.
Proteaceae are restricted to the Southern Hemisphere, and of the seven tribes of the subfamily Grevilleoideae, only three (Macadamieae, Oriteae, and Embothrieae) have living members in Argentina. Megafossil genera of Proteaceae recorded from Patagonia include Lomatia, Embothrium, Orites, and Roupala. In this report, we evaluate and revise fossil Argentine Proteaceae on the basis of type material and new specimens. The new collections come from the Tufolitas Laguna del Hunco (early Eocene, Chubut Province), the Ventana (middle Eocene, Río Negro Province), and the Río Ñirihuau (late Oligocene-early Miocene, Río Negro Province) formations, Patagonia, Argentina. We confirm the presence of Lomatia preferruginea Berry, L. occidentalis (Berry) Frenguelli, L. paragonica Frenguelli, Roupala patagonica Durango de Cabrera et Romero, and Orites bivascularis Romero, Dibbern et Gandolfo. Fossils assigned to Embothrium precoccineum Berry and E. pregrandiflorum Berry are doubtful, and new material is necessary to confirm the presence of this genus in the fossil record of Patagonia. A putative new fossil species of Proteaceae is presented as Proteaceae gen. et sp. indet. Fossil Proteaceae are compared with modern genera, and an identification key for the fossil leaf species is presented. Doubtful historical records of Proteaceae fossils for the Antarctic Peninsula region and Patagonia are also discussed. Based on this revision, the three tribes of Proteaceae found today in Argentina were already present in Patagonia by the early Eocene, where they probably arrived via the Australia-Antarctica-South America connection. [ABSTRACT FROM AUTHOR]