State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, 100083, China.
School of the Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, China.
Sci Rep. 2018 Jun 14;8(1):8770. doi: 10.1038/s41598-018-26848-w.
Frogs are a familiar and diverse component of tropical forests around the world. Yet there is little direct evidence from the fossil record for the antiquity of this association. We describe four fossil frog specimens from mid-Cretaceous (~99 mya) amber deposits from Kachin State, Myanmar for which the associated fauna provides rich paleoenvironmental context. Microcomputed tomographic analysis provides detailed three-dimensional anatomy for these small frogs, which is generally unavailable for articulated anurans in the Mesozoic. These crown-group anuran specimens provide the earliest direct evidence for anurans in a wet tropical forest. Based on a distinct combination of skeletal characters, at least one specimen has clear similarities to living alytoid frogs as well as several Mesozoic taxa known from the Jehol Biota in China. Whereas many Mesozoic frogs are from seasonal and mesic paleoenvironments, these fossils provide the earliest direct evidence of anurans in wet tropical forests.
青蛙是世界各地热带森林中常见且多样的组成部分。然而，化石记录中几乎没有直接证据表明这种联系的古老性。我们描述了来自缅甸克钦邦中白垩纪（约 9900 万年前）琥珀矿床的四个化石青蛙标本，这些标本的相关动物群提供了丰富的古环境背景。微计算机断层扫描分析为这些小青蛙提供了详细的三维解剖结构，这在中生代的关节两栖动物中通常是不可用的。这些有冠群的两栖动物标本为热带湿润森林中的有尾目动物提供了最早的直接证据。至少有一个标本具有明显的骨骼特征组合，与生活中的雨蛙科以及来自中国热河生物群的几个中生代分类群有明显的相似性。虽然许多中生代青蛙来自季节性和湿润的古环境，但这些化石为热带湿润森林中有尾目动物的存在提供了最早的直接证据。
