32 mln-yr-old tree fossil discovered in southwest China

Scientists have discovered a 32- million-year-old fossil of Dipteronia tree in Yunnan province.
In a study published in Review of Palaeobotany and Palynology, researchers described a newly discovered fossil occurrence of Dipteronia fruits from the early Oligocene.
They collected fossil dicotyledonous leaves and two winged fruits of Dipteronia in lacustrine mudstones near Luhe Town in Yunnan.
The researchers from the Chinese Academy of Sciences studied the fossil fruits morphologically and compared with both surviving and fossil representatives of Dipteronia.
The fossils showed combined characteristics of Dipteronia sinensis and Dipteronia brownii and fell within the range of morphological variability of D brownii.

Therefore, they adopted a broad circumscription and assigned their fossils to D brownii.
Dipteronia fruit fossils fall within the range of variation in general size and shape of Dipteronia sinensis, which demonstrates that the genus has retained its unique fruit morphology since the Palaeogene.
The new fossil discovery suggests that the palaeoendemic genus Dipteronia was widely distributed in North America and Asia.