Dicotyledonous Woods of the Cretaceous and Tertiary

晚白垩世和早第三纪是关键时期 在开花植物的历史上。 信息 这一时期的进化变化来自于 叶子，花粉，最近，花，果实和种子。 虽然化石，石化木材的开花植物出现 在美国的所有矿床中， 对它们的解剖结构进行了系统的研究。 伊丽莎白惠勒博士 北卡罗来纳州州立大学将研究解剖学， 白垩纪和白垩纪的几个组合的分类关系 第三纪的树木，来扩展我们对 特殊的植物群。 结构特征数据 在研究过程中检查的木材和数据， 文献将被编入计算机数据库。 变化 在木结构通过时间将被跟踪，并与 植物其他部分的变化。 这个项目的成功在很大程度上取决于 关于进入一个数据库的信息，木材解剖的一个 大量的物种。 这样的数据库已经 在北卡罗来纳州成立，并将扩大。 这 扩展将有助于化石木材的比较， 现存的植物，并将有利于任何人需要 鉴定活的和化石植物的木材样本。

The Late Cretaceous and Early Tertiary periods are critical times in the history of the flowering plants. Information about evolutionary changes during this period has come from the study of leaves, pollen, and most recently, flowers, fruits, and seeds. Although fossil, petrified woods of flowering plants occur throughout deposits in the United States, there have been few systematic studies of their anatomy. Dr. Elisabeth Wheeler of North Carolina State University will study the anatomy and taxonomic relationships of several collections of Cretaceous and Tertiary woods, to extend our understanding of the history of particular plant groups. Data on the structural characteristics of the woods examined during the study and data from the literature will be organized into a computer database. Changes in wood structure through time will be tracked, and compared with changes in other plant parts. The success of this project is dependent to a large degree on access to a database with information on the wood anatomy of a large number of living species. Such a database has been established at North Carolina State and will be expanded. This expansion will facilitate the comparison of fossil woods to extant plants, and will be of benefit to anyone needing to identify wood samples of both living and fossil plants.