Evidence for the evolutionary history and diversity of fossil sweetgums

Author(s)
Natalia P. Maslova, Tatiana M. Kodrul, Vasilisa V. Kachkina, Christa Charlotte Hofmann, Sheng Lan Xu, Xiao Yan Liu, Jian Hua Jin
Abstract

Extant species of Liquidambar L. exhibit a disjunct distribution between western and eastern Asia and eastern North America to Central America, with the highest species diversity being in China. In this study, two new species of Liquidambar are described from the Eocene of Hainan Island, South China: L. hainanensis on basis of the leaf fossils, and L. ovoidea based on compressions of infructescences. The co-occurrences of L. hainanensis leaves, associated infructescences of L. ovoidea and dispersed pantoporate pollen grains have the combination of morphological features peculiar to the genera Liquidambar and former Semiliquidambar and Altingia. This is considered further palaeobotanical justification for the placement of these three genera into a single genus, Liquidambar, proposed earlier based on molecular markers. Our data provide evidence for the occurrence of an ancestral polymorphic group of Liquidambar species (L. maomingensis with associated capitate infructescences, L. bella, L. hainanensis and L. ovoidea) during the Eocene in South China, and corroborate the view that South China could have been a centre of Liquidambar speciation during the Eocene. The morphological similarity of L. hainanensis leaves to those of the extant species L. orientalis from Western Asia and the North American L. styraciflua may support the importance of both the North Atlantic Land Bridge and the Bering Land Bridge for the dispersal of Liquidambar. Analysis of fossil species of Liquidambar from eastern Asia also contributes to further understanding of patterns in the taxonomic diversity and evolutionary history of this genus.

Organisation(s)
Department of Palaeontology
External organisation(s)
Sun Yat-sen University, Russian Academy of Sciences, Anuchin Research Institute and Museum of Anthropology, South China Normal University
Journal
Papers in Palaeontology
Volume
9
ISSN
2056-2799
DOI
https://doi.org/10.1002/spp2.1540
Publication date
11-2023
Peer reviewed
Yes
Austrian Fields of Science 2012
105118 Palaeontology
Keywords
ASJC Scopus subject areas
Palaeontology
Portal url
https://ucrisportal.univie.ac.at/en/publications/1173d196-a09d-4ea7-8278-a40d3f630540