Fruit fossils of Rosoideae (Rosaceae) from the late Pliocene of northwestern Yunnan, Southwest China

Abstract

The subfamily Rosoideae Focke (Rosaceae) has a good fossil record in the Northern Hemisphere, but these fossil records are confined mainly to a few genera, whereas the majority, in particular those with herbaceous members, are still under‐represented. In this study, we describe new fruit fossils of Rosoideae, including Fragaria achenes and Rubus endocarps, from the late Pliocene of northwestern Yunnan, Southwest China. These fossils add new accounts to the fossil archive of Rosoideae and provide the first fossil record of Fragaria in East Asia. The new fossil findings provide a historical backdrop for the modern diversity and distribution of the subfamily in northwestern Yunnan, a topographically complex area accommodating a high diversity for many plant groups. Our Rubus fossils, in combination with other nearby coeval occurrences of the genus, suggest that Rubus was already establishing its modern diversity in northwestern Yunnan during the late Pliocene. This finding enriches our knowledge of the post‐Neogene diversification of flowering plants in northwestern Yunnan, which is thought to be largely driven by dramatic mountain uplifts and environmental complications associated with the southeastern extension of the Tibetan Plateau.

Evolutionary history and pan-genome dynamics of strawberry ( Fragaria spp.)

“…We also estimated the age of divergences across the Fragaria phylogeny, using five fossils that possess synapomorphies of their respective clades as crown group calibrations (34)(35)(36), including the minimum age (2.9 Mya) for the root node of the north clade. Furthermore, a newly discovered achenes fossil of Fig.…”

“…Fragaria from the late Pliocene (2.6 to 3.6 Mya) in Yunnan, Southwest China (36) suggested that the south clade, at least, had originated before 2.6 Mya (the minimum age for the root node of the south clade). Based on these fossils, our estimate of the origin of Fragaria, 7.94 (6.5 to 10.3) Mya (Fig.…”

“…We also estimated the age of divergences across the Fragaria phylogeny, using five fossils that possess synapomorphies of their respective clades as crown group calibrations ( 34 – 36 ), including the minimum age (2.9 Mya) for the root node of the north clade. Furthermore, a newly discovered achenes fossil of Fragaria from the late Pliocene (2.6 to 3.6 Mya) in Yunnan, Southwest China ( 36 ) suggested that the south clade, at least, had originated before 2.6 Mya (the minimum age for the root node of the south clade). Based on these fossils, our estimate of the origin of Fragaria , 7.94 (6.5 to 10.3) Mya ( Fig.…”

Ecological and Biogeographic Implications of Asian Cenozoic Fossil Floras

“…Huang et al () report on distinctive fossil endocarps of Fragaria and Rubus (Rosaceae, subfamilies Rosoideae) from northwestern Yunnan, Southwest China. This discovery indicates that these genera, which are diverse in the same region today, were already part of the flora in the late Pliocene.…”

“…By comparison with the conditions in which extant Christella occurs, the authors infer that the Liuqu flora was deposited prior to major uplift in a warm humid habitat significantly lower in elevation than today. Huang et al (2019) report on distinctive fossil endocarps of Fragaria and Rubus (Rosaceae, subfamilies Rosoideae) from northwestern Yunnan, Southwest China. This discovery indicates that these genera, which are diverse in the same region today, were already part of the flora in the late Pliocene.…”