The late Pliocene species with ternate venation of Lauraceae from Tuantian flora, Tengchong, Yunnan Province, China  

作　　者：DAO KeQun DONG Chong XU XiaoHui DU BaoXia WU JingYu XIE SanPing SUN BaiNian 

机构地区：[1]School of Earth Sciences and Key Laboratory of Mineral Resources in Western China,Lanzhou University [2]Lanzhou University Library [3]Lanzhou University

出　　处：《科学通报》2013年第S1期193-199,共7页Chinese Science Bulletin

基　　金：supported by the National Basic Research Program of China(2012CB822003);the National Natural Science Foundation of China(41172022 and 41172021);the Fundamental Research Funds for the Central Universities(lzujbky-2012-127)

摘　　要：A number of fossil leaves of the Lauraceae were collected from Tuantian flora of the late Pliocene strata in Yunnan, China. They have a whole leaf shape and well-preserved cuticles. In this paper, features of the architecture and epidermis of three species of the Lauraceae family with ternate venation are reported. Results of the comparison between the venation characteristics of Lauraceae fossils from four fossil floras in the world and those of extant Lauraceae in China suggest that the proportion of Lauraceae species with ternate venation is increasing. The proportion has risen from 10% in the Eocene to 12.5% in the late Pliocene in China, whereas the proportion in the modern era is 21%. Moreover, the proportion of Australian floras with ternate venation has rised from 8.3% to 10% between the Eocene and the Miocene. Because of the effect of the global drought during the Cenozoic era, we suggested that species with ternate venation in Lauraceae have become increasingly prevalent between the Eocene era and the present day in China. Data on Nerriga flora and Maarlake flora since the Eocene era in the Southern Hemisphere show the same trend. While features of the leaf architecture and epidermis of Lindera acuminatissima differ in details. They all have similar identification characteristics with regard to basal eucamptodromous venation, interior 2° present, minor 2° simple brochidodromous, anticlinal walls, no surface ornamentation, lip-like guard cells, outer stomatal ledge plain or dimness, and paracytic stomatal aperture. These differences are also present in extant species. Compared with Lindera tonkinensis, the nearest living relative(NLR) of L. acuminatissima shows that these differences are relevant to the growth, position, and development of leaves. Leaf-type classification statistics of L. acuminatissima indicate that when all fossil leaves are taken into consideration, A-type leaves account for 24%, B-type leaves make up 56%, and C-typy leaves account for 20%. Comparing the above result with that of NLA number of fossil leaves of the Lauraceae were collected from Tuantian flora of the late Pliocene strata in Yunnan, China. They have a whole leaf shape and well-preserved cuticles. In this paper, features of the architecture and epidermis of three species of the Lauraceae family with ternate venation are reported. Results of the comparison between the venation characteristics of Lauraceae fossils from four fossil floras in the world and those of extant Lauraceae in China suggest that the proportion of Lauraceae species with ternate venation is increasing. The proportion has risen from 10% in the Eocene to 12.5% in the late Pliocene in China, whereas the proportion in the modern era is 21%. Moreover, the proportion of Australian floras with ternate venation has rised from 8.3% to 10% between the Eocene and the Miocene. Because of the effect of the global drought during the Cenozoic era, we suggested that species with ternate venation in Lauraceae have become increasingly prevalent between the Eocene era and the present day in China. Data on Nerriga flora and Maarlake flora since the Eocene era in the Southern Hemisphere show the same trend. While features of the leaf architecture and epidermis of Lindera acuminatissima differ in details. They all have similar identification characteristics with regard to basal eucamptodromous venation, interior 2° present, minor 2° simple brochidodromous, anticlinal walls, no surface ornamentation, lip-like guard cells, outer stomatal ledge plain or dimness, and paracytic stomatal aperture. These differences are also present in extant species. Compared with Lindera tonkinensis, the nearest living relative(NLR) of L. acuminatissima shows that these differences are relevant to the growth, position, and development of leaves. Leaf-type classification statistics of L. acuminatissima indicate that when all fossil leaves are taken into consideration, A-type leaves account for 24%, B-type leaves make up 56%, and C-typy leaves account for 20%. Comparing the above result with that of NL

关 键 词：LAURACEAE ternate VENATION FOSSIL leaves Yunnan the late PLIOCENE 

分 类 号：Q914[天文地球—古生物学与地层学]