ANCIENT BISEXUAL FLOWERS
ANCIENT BISEXUAL FLOWERS
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DOI：
10.1126/science.224.4648.511
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发表时间：
1984-01-01
期刊：
影响因子：
56.9
通讯作者：
DILCHER, DL
中科院分区：
文献类型：
--
作者：
BASINGER, JF;DILCHER, DL
在内布拉斯加州[美国][中白垩纪]达科他组粘土中发现的具有 9400 万年历史的花朵化石是已知最早的双性花之一。花中等大小，有五轮轮生的花部分明显不同，花瓣与萼片互生，短雄蕊与花瓣相对，心皮融合，存在花托盘。花粉很小，呈三孔状。这些花似乎很好地适应了昆虫授粉。众多的花特征和花粉特征提供了足够的诊断数据来评估其系统地位。没有现存的目能够容纳这种花的特征，并且它共享各种现存目的一些特征。开花植物的分类和对其进化的理解必定受到古代花卉化石遗骸的影响。
Fossil flowers discovered in 94 million year old clays of the Dakota Formation in Nebraska [USA] [Middle Cretaceous] are among the earliest known demonstrably bisexual flowers. The flowers are of medium size and have pentamerous whorls of clearly differentiated floral parts, petals alternate with the sepals, short stamens are borne opposite the petals, the carpels are fused and a receptacular disk is present. The pollen is small and tricolporate. These flowers appear to be well adapted to insect pollination. The numerous floral features and pollen characters provide sufficient diagnostic data to assess its systematic position. No extant order accommodates the features of this flower and it shares some features of various extant orders. The classification of flowering plants and understanding of their evolution must be influenced by the fossilized remains of ancient flowers.