Fossil nothofagaceous leaves from the Eocene of western Antarctica and their bearing on the origin, dispersal and systematics of Nothofagus  

作　　者：LI HaoMin1 & ZHOU ZheKun2? 1 State Key Laboratory of Palaeobiology & Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sci- ences, Nanjing 210008, China 2 Key Laboratory of Biodiversity and Biogeography, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, China 

出　　处：《Science China Earth Sciences》2007年第10期1525-1535,共11页中国科学（地球科学英文版）

基　　金：Foundation of State Key Laboratory of Palaeobiology & Stratigra-phy, Nanjing Institute of Geology and Palaoentology, Chinese Academy of Sciences (Grant No. 013106);the National Natural Science Foundation of China (Grant No. 30670159);the Fund of Innovation Program by Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences

摘　　要：Fossil leaves resembling Nothofagaceae have been investigated from the Eocene of western Antarctica and a new form genus Nothofagofolia is proposed for these kinds of fossils. Some new specimens belonging to this form genus are described. They were collected from the Fossil Hill locality of Fildes Peninsula, King George Island, South Shetland Islands, western Antarctica. Two new species, two new combinations and an unnamed species are reported. A number of published Nothofagus leaf fossils from the same locality are discussed and revised. As a result of these studies of Nothofagus leaf morphology, we conclude that (1) Nothofagus probably originated in high latitudes of the Southern Hemisphere during the middle-late Late Cretaceous and diversified, dispersed gradually to the lower latitudes of the same hemisphere; (2) leaf morphological characters are significant for the systematics of the family Nothofagaceae, especially at the intrageneric level; and (3) extant species of Nothofagus known from southern temperate areas have more primitive leaf morphological characters and lower leaf ranks than those from tropical mountains as well as those of the Fagaceae and Betulaceae.Fossil leaves resembling Nothofagaceae have been investigated from the Eocene of western Antarctica and a new form genus Nothofagofolia is proposed for these kinds of fossils. Some new specimens belonging to this form genus are described. They were collected from the Fossil Hill locality of Fildes Peninsula, King George Island, South Shetland Islands, western Antarctica. Two new species, two new combinations and an unnamed species are reported. A number of published Nothofagus leaf fossils from the same locality are discussed and revised. As a result of these studies of Nothofagus leaf morphology, we conclude that (1) Nothofagus probably originated in high latitudes of the Southern Hemisphere during the middle-late Late Cretaceous and diversified, dispersed gradually to the lower latitudes of the same hemisphere; (2) leaf morphological characters are significant for the systematics of the family Nothofagaceae, especially at the intrageneric level; and (3) extant species of Nothofagus known from southern temperate areas have more primitive leaf morphological characters and lower leaf ranks than those from tropical mountains as well as those of the Fagaceae and Betulaceae.

关 键 词：Antarctica  Nothofagus  LEAF morphology  LEAF impression fossils  Gondwanaland  Nothofagofolia gen. et sp. nov.  EOCENE 

分 类 号：Q956[生物学—动物学]