Cretaceous (Turonian) Angiosperm Flowers from New Jersey (USA): Structural Diversity, Systematics, and Phylogenetic/Evolutionary Implications

来自新泽西州（美国）的白垩纪（土兰纪）被子植物花：结构多样性、系统学和系统发育/进化意义

• 批准号: 0108369
• 负责人: William Crepet
• 金额: --
• 依托单位: Cornell Univ - State: AWDS MADE PRIOR MAY 2010
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-01 至 2005-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0108369&HistoricalAwards=false
• 关键词: Cretaceous; Turonian; Angiosperm; Flowers; New

Drs. Crepet and Nixon have been awarded a grant to study significant deposits of fossil flowering plants. These deposits represent some of the finest fossil sites ever discovered including a virtual treasure trove of exquisitely preserved fossil flowers-a kind of fossil with enormous potential scientific value and one once thought to be prohibitively rare and beyond the reach of science(at least 200 species-more than all other reports of similar aged fossils combined). Flowering plants are the most dominant, diverse, economically [including medicinally], and ecologically important groups of existing plants. Uncertainties exist as to origins, relationships and reasons for their success. Together, these unknowns circumscribe "Darwin's Abominable Mystery" and it constitutes one of the most visible voids in our understanding of the history of life. In spite of recent progress based on breakthroughs using molecular data to determine taxonomic relationships, extinct missing links would be helpful in understanding the history, relationships and success of the flowering plants by filling some of the gaps now separating living species and by introducing "historical testability" to hypotheses of relationships that are based exclusively on comparisons among living species. In other words, if hypothesized relationships are inconsistent with newly discovered fossil taxa (that is, if the attributes of the fossils cause them not to fit into and thus challenge modern hypotheses), then the hypothesis or the interpretation of the fossil is incorrect and a careful study should ensue. Also, the pattern of appearance of different species generated by such studies should be roughly compatible with the evolutionary sequence implied by hypotheses based only on living species-if there is a conflict further examination of all data and interpretations is in order. Yet another particularly significant benefit of this investigation is its contribution to establishing a sequence of appearance of different floral types through time. In addition to including many of the taxonomically important structural characteristics of angiosperms, flowers provide a key to the reproductive biology of their species, particularly pollination biology. Knowing the pattern of appearance of various modes of pollination from fossil evidence will be most helpful in evaluating various hypotheses seeking to explain angiosperm success-especially those relating angiosperm diversity to mode of pollination. Thus studies of fossils at this locality stand to provide important insights into what has widely been recognized as a major gap in our knowledge.The proposed research will include a diverse set of approaches to and interests in angiosperm fossil history, floral evolution, history of pollination and insect-plant interactions, phylogenetic relationships of angiosperm groups, origin of angiosperms, history of monocots, Cretaceous gymnosperm and fern diversification, and theoretical and practical aspects of cladistic analysis and phylogenetic reconstruction involving new algorithms and approaches to placing the fossils in phylogenetic context. Drs. Crepet and Nixon will continue fieldwork aimed at discovering additional species. They continue to find additional taxa of great interest and potential importance. Existing and newly collected fossils will be intensively studied in order to elucidate the structural details and taxonomic affinities of as many as possible. Particular attention will be paid to certain groups of critical interest that are well or uniquely represented in the collections. The careful explication of fossil structure depends upon light and electron microscopy (particularly SEM). Fossils, once described, will further require a significant curation and databasing effort. The next step is the evaluation of the relationships of the fossils through the process of contrasting their characteristics with those of all other known flowering plants. This process, phylogenetic analysis, involves computer algorithms and results are testable and reproducible and provide accurate assessments of the taxonomic affinities of the fossils. Thus, a carefully produced reliable pattern of angiosperm floral history is established. These fossils already encompass the earliest evidence of numerous angiosperm lineages and they include the oldest documented examples of numerous features and species with important implications for the pattern and timing of evolution of pollination mechanisms. In toto these fossils provide a breathtaking array of floral innovations from a relatively early and critical period in angiosperm diversification. The fossils include enough representatives of major taxonomic groups, including the earliest reliable evidence of the monocots (wheat, grasses, orchids etc.) to strongly alter our perception of the timing of flowering plant evolution.The project has the potential to provide quantities of unique data that will be relevant to many other workers in these areas including especially angiosperm systematists and pollination biologists. These data will in the form of primary (descriptions, phylogenetic matrices), and secondary results (e.g. phylogenetic trees including fossils, insights into the history of angiosperm-insect relationships, and minimum ages of extinct lineages). In addition to publishing the results and cooperatively sharing them with colleagues including graduate students being trained in this area, a website will be maintained that will make specific data and photographs available to the scientific community. The PI's will continue to publish results of their work in the form of popular articles in order to reach a broad segment of the public.

Crepet博士和尼克松博士获得了一笔赠款，用于研究显花植物化石的大量沉积物。这些沉积物代表了迄今为止发现的一些最好的化石遗址，包括一个保存精美的化石花的虚拟宝库一种具有巨大潜在科学价值的化石，一种曾经被认为是极其罕见的，超出了科学研究范围的化石（至少有200种，比所有其他类似年龄化石的总和还要多）。有花植物是现存植物中最具优势、多样性、经济上（包括药用上）和生态上重要的类群。 它们的起源、关系和成功的原因是不确定的。总之，这些未知数限制了“达尔文的可憎之谜”，它构成了我们对生命历史理解中最明显的空白之一。 尽管最近在利用分子数据确定分类学关系方面取得了突破性进展，但灭绝的缺失环节将有助于理解显花植物的历史、关系和成功，填补了现在分离活物种的一些空白，并将“历史可检验性”引入到完全基于活物种之间比较的关系假设中。换句话说，如果假设的关系与新发现的化石分类群不一致（也就是说，如果化石的属性使它们不符合现代假设，从而挑战现代假设），那么假设或对化石的解释是不正确的，应该进行仔细的研究。 此外，由这些研究产生的不同物种的外观模式应该与仅基于活物种的假设所暗示的进化顺序大致一致如果存在冲突，则需要对所有数据和解释进行进一步检查。这项研究的另一个特别重要的好处是它有助于建立不同花型随时间的出现顺序。除了包括被子植物的许多分类学上重要的结构特征外，花还提供了其物种生殖生物学，特别是授粉生物学的关键。从化石证据中了解各种授粉方式的出现模式，将有助于评估各种试图解释被子植物成功的假说，特别是那些将被子植物多样性与授粉方式联系起来的假说。因此，对该地区化石的研究将为我们的知识提供重要的见解，这一点已被广泛认为是我们知识中的一个重大空白。拟议的研究将包括被子植物化石历史、花的进化、传粉和昆虫-植物相互作用的历史、被子植物群的系统发育关系、被子植物的起源、单子叶植物的历史、白垩纪裸子植物和蕨类植物的多样化，以及分支分析和系统发育重建的理论和实践方面，涉及新的算法和方法，把化石的系统发育背景。 Crepet博士和尼克松博士将继续实地考察，旨在发现更多的物种。他们继续发现其他具有极大兴趣和潜在重要性的分类群。现有的和新收集的化石将被深入研究，以阐明尽可能多的结构细节和分类学上的亲缘关系。将特别注意在收藏中有很好或独特代表的某些关键利益群体。化石结构的仔细解释取决于光学和电子显微镜（特别是扫描电子显微镜）。化石一旦被描述，将进一步需要大量的管理和数据库工作。下一步是通过将这些化石的特征与所有其他已知的开花植物的特征进行对比，来评估它们之间的关系。这个过程，系统发育分析，涉及计算机算法和结果是可测试的和可重复的，并提供准确的评估化石的分类亲缘关系。因此，一个精心制作的可靠的被子植物花的历史模式建立。这些化石已经包含了许多被子植物谱系的最早证据，它们包括了许多特征和物种的最古老的记录实例，这些特征和物种对授粉机制的进化模式和时间具有重要意义。总的来说，这些化石提供了被子植物多样化相对早期和关键时期的一系列令人惊叹的花卉创新。这些化石包括足够多的主要分类群的代表，包括单子叶植物（小麦、草、兰花等）的最早可靠证据该项目有可能提供大量独特的数据，这些数据将与这些领域的许多其他工作者相关，特别是被子植物系统学家和授粉生物学家。这些数据将以主要（描述，系统发育矩阵）和次要结果（例如，包括化石的系统发育树，对被子植物-昆虫关系历史的见解，以及灭绝谱系的最小年龄）的形式提供。除了公布结果并与包括正在接受这一领域培训的研究生在内的同事合作分享这些结果外，还将维护一个网站，向科学界提供具体的数据和照片。PI将继续以受欢迎的文章形式发表其工作成果，以便接触到广大公众。