A new pod record of Acacia (Leguminosae) from the Fotan Group, middle Miocene, Southeast China

Leguminosae has a long fossil history, dating back to the Late Cretaceous, and the Mimosoideae are documented in lower Eocene fossil records. The considerable diversity and cosmopolitan distribution of the legume family make it useful for understanding the vegetation history of low-latitude China. Here, we describe a new species of Acacia based on compressed pods from the middle Miocene Fotan Group in Fujian Province, Southeast China. This is the first fossil record of Acacia in South China suggesting that this genus grew in this region during the middle Miocene. Our legume fossils together with earlier records, indicate that a flora with an unusual abundance of legumes was present in Fujian Province, South China, during the Miocene. The relatively high species diversity of Leguminosae and other plants, such as Dipterocarpaceae, Lauraceae, Moraceae, Calophyllaceae, Urticaceae, Euphorbiaceae, Fagaceae and Clusiaceae, corroborate that the Miocene Zhangpu flora has lived in a warm and humid climate. This finding provides additional evidence of the biogeographic history of this genus and represents the only confirmed occurrence of Acacia fossil pods from lower-latitude China, which provides new insights into the diversification of Acacia during the Neogene.