山东临朐中中新世山旺组紫藤属(豆科)荚果化石的再观察  

FURTHER OBSERVATIONS ON THE POD FOSSILS OF WISTERIA(LEGUMINOSAE) FROM THE MIDDLE MIOCENE SHANWANG FORMATION OF LINQU,SHANDONG PROVINCE

作　　者：张静[1,2] 王祺[1] 

机构地区：[1]中国科学院植物研究所,系统与进化植物学国家重点实验室,北京100093 [2]中国科学院研究生院,北京100049

出　　处：《古生物学报》2010年第1期87-95,共9页Acta Palaeontologica Sinica

基　　金：国家自然科学基金(40830209);中国科学院知识创新工程重要方向性项目(植物园与生物分类学研究专项)(KSCX2-YW-Z-063);中国科学院公派出国留学基金项目;中国科学院植物研究所基金(110100P008)联合资助

摘　　要：豆科紫藤属Wisteria约有5-6个现生种,间断分布于中国、日本和美国的温带地区,但化石记录表明,该属在新近纪可能广泛分布于捷克、荷兰、格鲁吉亚阿布哈兹、保加利亚、罗马尼亚、俄罗斯远东、日本和中国。因此,研究紫藤属化石有助于深入认识它的早期演化、分类、多样性、古生态和生物地理,其中荚果化石的分类价值和演化意义尤为显著。文中基于对产自山东临朐中中新世山旺组的山旺紫藤W.shanwangensis荚果化石的再观察,并结合紫藤属3个现生种——紫藤W.sinensis、藤萝W.villosa和多花紫藤W.floribunda的荚果发育特征,讨论这些化石的分类、演化、发育和埋藏学意义。结果进一步证明,山旺紫藤荚果化石与国产的2个现生种——紫藤和藤萝的荚果更为相似,呈倒披针形、种子较少和室间缢缩明显。比较而言,日本和美国产的紫藤属现生种——多花紫藤和美国紫藤W.frutescens的荚果呈线形、种子较多和室间缢缩不明显,而且日本中新世和上新世报道的紫藤属荚果化石与多花紫藤的荚果更为相似。然而,中国和日本报道的紫藤属荚果化石迄今都没发现被毛,这与现生种中最原始的美国紫藤的荚果相似,而与东亚紫藤属现生种密被绒毛的荚果形成显著差别。因此,中国、日本和美国的紫藤属种类可能早在中新世就已经发生了形态地理分化,而荚果无毛或许是该属演化过程中一个比较原始的性状;紫藤属现生种荚果在发育的中、后期果壁上具有与纵轴方向成锐角的倾斜纤维纹饰,它们在荚果完全成熟后导致果瓣沿缝线开裂并卷曲,卷曲的果瓣放入水中又能恢复平整。值得注意的是,山旺紫藤荚果化石果壁上也发现了类似的倾斜纤维纹饰,这表明它们在脱落保存时处在发育的中、后期,这一发育时期脱落的荚果更有可能保存为化石记录;山旺紫藤荚果化石果壁的碳质残片�Wisteria Nutt,1818 （Leguminosae,Papilionoideae） includes about five or six living species,disjunctly distributed in the temperate regions of China,Japan,and the USA.The fossil record indicates that this genus might have widely occurred in the Czech Republic,Holland,Georgian Abkhazia,Bulgaria,Romania,Russian Far East,Japan,and China since the Neogene.Therefore,the fossil record of Wisteria,especially its pod fossils,can provide useful data for a better understanding of its early evolution,taxonomy,diversity,paleoecology and biogeography.In light of the developmental features of pods in three living wisterias （i.e.,W.sinensis,W.villosa and W.floribunda）,we examine the pod fossils of W.shanwangensis from the Middle Miocene Shanwang Formation of Linqu County,Shandong Province and discuss their implications for taxonomy,evolution,development and taphonomy.Our results demonstrate that the pod fossils of W.shanwangensis show more similarity to the two living wisterias （i.e.,W.sinensis and W.villosa） native to China,in having oblanceolate contour,fewer seeds and distinct constrictions between the seed-bearing chambers.In contrast,the pods of the Japanese wisteria W.floribunda and the American wisteria W.frutescens are linear,bearing more seeds and indistinct constrictions,and the pods from the Mio-Pliocene of Japan are more similar to those of W.floribunda.However,the trichomes have thus far not been observed on the pod fossils of Wisteria from China and Japan nor on the most primitive USA living species W.frutescens.These glabrous species are significantly distinguished from the living wisterias in eastern Asia with dense hairy pods.Therefore,wisterias in China,Japan and USA may have undergone morphological-geographic differentiation as early as in the Miocene,and the glabrous pod is likely to be a more primitive character in the course of evolution of Wisteria.The chamber walls of the living wisterias are built up with parallel fibres during the mid-terminal stages of pod development,and these fibres run ob

关 键 词：豆科 紫藤属 荚果化石 生物地理 发育 埋藏学 山旺组 中新世 

分 类 号：Q914[天文地球—古生物学与地层学]