Extending beyond Gondwana: Cretaceous Cunoniaceae from western North America
Extending beyond Gondwana: Cretaceous Cunoniaceae from western North America
复制标题
延伸到冈瓦纳大陆之外：来自北美西部的白垩纪库尼亚科
DOI：
10.1111/nph.17976
复制
发表时间：
2022
期刊：
影响因子：
9.4
通讯作者：
Atkinson, Brian A.
中科院分区：
文献类型：
--
作者：
Tang, Keana K.;Smith, Selena Y.;Atkinson, Brian A.
Cunoniaceae是南半球热带雨林的重要组成部分。这些开花植物中的许多被认为是古南极雨林谱系，自古新世以来就有冈瓦纳分布。该科几个现代属的化石，如角瓣木属（Ceratopetalum），表明了新生代南美洲和澳大利亚之间的地理联系。美国华盛顿苏西亚岛沉积。化石的研究采用了物理切片、光学显微镜、微型计算机断层扫描和多重系统发育分析。化石果实与角瓣属植物具有共同的特征，例如存在4至5个宿存萼裂片、一个突出的蜜腺盘、宿存雄蕊、半下位子房和两种宿存花柱。通过与现存种果实的形态学比较和系统发育分析，将这些化石归属于一个新种Ceratopetalum suciensis，这是首次明确的北美白垩纪冠状Cunoniaceae的证据，表明这一重要的冈瓦纳科有着更为复杂的地理历史。
Cunoniaceae are important elements of rainforests across the Southern Hemisphere. Many of these flowering plants are considered Paleo‐Antarctic Rainforest Lineages that had a Gondwanan distribution since the Paleocene. Fossils of several modern genera within the family, such asCeratopetalum, have indicated biogeographical connections between South America and Australia in the Cenozoic.Here, we report a dramatic geographical range extension forCeratopetalum, and Cunoniaceae as a whole, based on two exceptionally preserved fossil winged fruits from Campanian (c. 82–80 Ma old) deposits on Sucia Island, Washington, USA. The fossils were studied using physical sectioning, light microscopy, micro‐computed tomography scanning and multiple phylogenetic analyses.The fossil fruits share diagnostic characters withCeratopetalumsuch as the presence of four to five persistent calyx lobes, a prominent nectary disk, persistent stamens, a semi‐inferior ovary and two persistent styles. Based on morphological comparisons with fruits of extant species and support from phylogenetic analyses, the fossils are assigned to a new speciesCeratopetalum suciensis.These fossils are the first unequivocal evidence of crown Cunoniaceae from the Cretaceous of North America, indicating a more complicated biogeographical history for this important Gondwanan family.