An association of Liquidambar (Altingiaceae) vegetative and reproductive structures from the Miocene of South China

Abstract

Liquidambar is a classic example of the eastern Asian–eastern North American biogeographic disjunction, and its fossil record is critical for understanding the evolutionary history and taxonomy of Altingiaceae. In particular, associated vegetative and reproductive fossils provide key evidence for evaluating the long-debated circumscription of Liquidambar s. l., including the formerly recognized genera Altingia and Semiliquidambar . Here, we describe associated Miocene fossils from the Guiping Basin, South China, representing three new species of Liquidambar . The staminate inflorescence with in situ pollen of L. tengxianensis sp. nov. and the leaf of L. prechinensis sp. nov. show close similarity to the extant Chinese species L. chinensis, whereas the capitate infructescence L. mesoaltingiana sp. nov. is comparable to that of Chinese species formerly placed in Altingia . Together, these fossils may indicate that, by the Miocene, some lineages within Liquidambar had already acquired more distinct morphological identities than those seen in the mosaic Paleogene record of South China. This pattern may reflect early morphological differentiation within the genus or, alternatively, an overall increase in morphological variation driven by shared ancestral traits or convergence.