The fossil record of Aponogeton (Aponogetonaceae) is scarce and the few reported macrofossil findings are in need of taxonomic revision. Aponogeton pollen is highly diagnostic and when studied with light microscopy (LM) and scanning electron microscopy (SEM) it cannot be confused with any other pollen types. The fossil Aponogeton pollen described here represent the first reliable Cretaceous and Eocene records of this genus worldwide. Today, Aponogeton is confined to the tropics and subtropics of the Old World, but the new fossil records show that during the late Cretaceous and early Cenozoic it was thriving in North America and Greenland. The late Cretaceous pollen record provides important data for future phylogenetic and phylogeographic studies focusing on basal monocots, especially the Alismatales. The Eocene pollen morphotypes from North America and Greenland differ in morphology from each other and also from the older Late Cretaceous North American pollen morphotype, indicating evolutionary trends and diversification within the genus over that time period. The presence of Aponogeton in the fossil record of North America and Greenland calls for a reconsideration of all previous ideas about the biogeographic history of the family.

中文翻译：

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来自北美和西格陵兰白垩纪和古近纪的Aponogeton花粉：对该属的起源和古生物地理学的影响


Aponogeton（Aponogetonaceae）的化石记录很少，少数报道的大型化石发现需要进行分类学修订。 Aponogeton 花粉具有高度诊断性，当用光学显微镜 (LM) 和扫描电子显微镜 (SEM) 研究时，它不会与任何其他花粉类型混淆。这里描述的 Aponogeton 花粉化石代表了世界范围内该属第一个可靠的白垩纪和始新世记录。如今，Aponogeton 仅限于旧世界的热带和亚热带地区，但新的化石记录显示，在白垩纪晚期和新生代早期，它在北美和格陵兰岛繁衍生息。白垩纪晚期的花粉记录为未来以基础单子叶植物，特别是泽泻目为重点的系统发育和系统发育地理学研究提供了重要数据。来自北美和格陵兰岛的始新世花粉形态类型彼此不同，也与较古老的晚白垩世北美花粉形态类型不同，表明该属在该时期的进化趋势和多样化。北美和格陵兰岛化石记录中阿波诺吉顿的存在要求我们重新考虑之前有关该科生物地理历史的所有观点。