Miocene Dipteronia (Sapindaceae) samaras from South Korea and their biogeographical implications
Lin-Bo Jia,
Gi-Soo Nam,
Tao Su,
Xia Yang,
Zhe-Kun Zhou,
Yun-Heng Ji
Affiliations
Lin-Bo Jia
CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; State Key Laboratory of Palaeobiology and Stratigraphy (Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences), Nanjing 210008, Jiangsu, China; Corresponding author
Gi-Soo Nam
Gongju National University of Education, 27, Ungjin-ro, Gongju-si, Chungcheongnam-do 32553, Korea
Tao Su
Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China; University of the Chinese Academy of Sciences, Beijing 100049, China
Xia Yang
CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
Zhe-Kun Zhou
Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China
Yun-Heng Ji
CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; Corresponding author
Summary: Dipteronia, now endemic to East Asia, was widely distributed in North America during the Paleogene; however, its fossil records in Asia are scarce and none are of the Neogene. Here, we report the first Neogene Dipteronia samaras from South Korea. The more complete fossil records suggest that Dipteronia possibly originated in either Asia or North America and that its two known lineages have different geographical histories. The Dipteronia sinensis lineage was established in Asia and North America in the Paleocene and reached its maximum range in the Eocene, followed by stepwise range contraction and extirpation in North America, South Korea, and southwestern China, finally becoming endemic to central China. In contrast, the Dipteronia dyeriana lineage might have been restricted to southwestern China, where it originated, indicating historical confinement. The current restricted distribution of Dipteronia possibly resulted from its evolutionary deceleration in a constantly changing environment.
