A fossil fig from the Miocene of southwestern China: Indication of persistent deep time karst vegetation

Foliage fossils of a fig, Ficus microtrivia J. Huang et Z. K. Zhou sp. nov. (Moraceae) is reported from early to middle Miocene lacustrine sediments in the Wenshan Basin, Yunnan, southwestern China. The leaf architecture and preserved exocrine veinlet glands on the fossils are irrefutable evidence for genus-level systematic assignment. Four venation patterns in the extant genus Ficus L. are summarised and established, subgenus and species level comparisons of the fossils are applied according to this framework. The nearest living relative of the new fossil-species is Ficus trivia Corner of Subgen. Ficus, a species restricted to the karst shrub habitat in southern China and northern Vietnam. Together with other elements of the fossil assemblage, this species indicates that open, shrubby vegetation on limestone similar to that in the same region today, already existed in the early to middle Miocene.