Abstract Paleocene leaf floras are rare in high latitudes of the Southern Hemisphere, where studies have shown higher taxonomic diversity compared to Northern Hemisphere equivalents. The floras provide valuable insights into biodiversity and forest communities during the Paleocene. The Antarctic Peninsula hosts a wealth of Paleocene–Eocene floras which have been used to interpret climates before, during and after one of the most abrupt and transient warming events known from the geological record. The best-preserved and most diverse Paleocene macrofossils from this region come from the Cross Valley Formation, Seymour Island Group, which have previously provided evidence for warm temperate climates prior to the PETM. Here we present the taxonomy of leaf impressions from the Paleocene Cross Valley Flora for one species and ten new leaf morphotypes of entire-margined angiosperms. The new morphotypes provide evidence of an increased angiosperm diversity within cool-temperate Gondwanan forest inhabiting the east side of the Antarctic Peninsula, which contrasts with a lower floral diversity on the west side of the Peninsula during the late Paleocene.

中文翻译：

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南极洲古新世高纬度叶植物群第 1 部分：全缘被子植物

摘要 古新世叶植物群在南半球高纬度地区很少见，研究表明，与北半球同类相比，该地区的分类多样性更高。植物群提供了对古新世生物多样性和森林群落的宝贵见解。南极半岛拥有丰富的古新世-始新世植物群，这些植物群被用来解释地质记录中已知的最突然和短暂的变暖事件之一之前、之中和之后的气候。该地区保存最完好和最多样化的古新世大型化石来自西摩岛群的 Cross Valley 地层，该地层此前曾为 PETM 之前的暖温带气候提供了证据。在这里，我们展示了来自古新世 Cross Valley Flora 的叶印象分类法，用于整个边缘被子植物的一个物种和十个新叶形态类型。新的形态类型提供了居住在南极半岛东侧的凉爽温带冈瓦纳森林中被子植物多样性增加的证据，这与晚古新世期间半岛西侧的较低的花卉多样性形成对比。