The rediscovery of alpine oak(Heterobalanus group,Quercus section Ilex,Fagaceae)fossils from Mount Shisha Pangma and its significance
We reported alpine oak fossil leaves(the Heterobalanus group,Quercus section Ilex,Fagaceae)rediscovered on Mount Shisha Pangma.According to twice field investigations,the fossil site is located at the front of the No.5 glacier tongue on the south side of the Dasuopu Glacier at an altitude of about 5800m on the north slope of Shisha Pangma Peak.These fossils are from the siltstone interlayer dominated by sandy conglomerate in the lower part of the Yebokangjiale Group.These newly discovered fossil leaves have typical characteristics of alpine oaks,including oval or oblong leaf,thick and short petiole,entire or toothed leaf margin,and 5～6 pairs of secondary veins,which is completely consistent with the leaf morphology of alpine oaks from Mount Shisha Pangma reported previously.Through morphological comparison with living and fossil species in this group,as well as quantitative analysis combined with geometric morphometry,these fossil leaves from Mount Shisha Pangma were assigned to Quercus preguajavifolia Tao.Alpine oaks may originate in southeastern margin of the Qinghai-Tibetan Plateau,then thrive locally and spread into regions nearby accompanying by the uplift of the plateau.The implication of alpine oak fossil leaves from Mount Shisha Pangma on paleoelevation needs to be further investigated due to the present wide range and the uncertainty of these fossils.The rediscovery of alpine oak fossils from Mount Shisha Pangma not only helps to clarify the specific layers bearing these fossils,but also further enriches the morphological characteristics of this fossil record and its systematic position.This discovery would provide important basis for better revealing the evolution of biodiversity and environmental changes in the middle part of the Himalaya during the Cenozoic.
NETL
NSTL
万方数据
维普
