Palmately Lobed Proteaceae Leaf Fossils from the Middle Eocene of South Australia

Parafatsia subpeltata D. T. Blackburn from the Middle Eocene of Maslin Bay, South Australia, is reinterpreted as belonging to extinct Proteaceae rather than Araliaceae, as originally described. Leaf cuticles of Parafatsia exhibit brachyparacytic stomata and annular trichome bases associated with numerous basal epidermal cells, features that are diagnostically proteaceous. The leaf architecture is unique in Proteaceae in being palmately lobed, with basal actinodromous primary venation. Parafatsia leaves were very large with highly ornamented cuticles. They were presumably derived from evergreen, light-demanding woody plants that evolved in the high-latitude, warm, humid environments of the Southern Hemisphere but subsequently became uncompetitive as Australia drifted into lower latitudes.