Fossil frogs from the upper Miocene of southwestern Brazilian Amazonia (Solimões Formation, Acre Basin)

Much of what we know about late Miocene vertebrates from the Brazilian Amazonia is based on the fossil record from several sites in the Solimões Formation. The Talismã site, one of the most important for vertebrate fossils in the formation, has produced an abundant and diverse fauna dominated by crocodylians, mammals, and turtles, but small vertebrates are still underrepresented. We report some isolated bones recovered from this site, providing the first Neogene records of anurans in Brazil. Two taxa are recognized, a distinct species of Pipa, and an unidentified species of the Rhinella clade, both of which are members of the extant Amazonian batrachofauna. These new fossils expand our knowledge of the late Miocene anuran assemblages from the region and contribute to the paleoenvironmental reconstruction of the site.

我们对巴西亚马孙地区晚中新世脊椎动物的认知，大多源自索利蒙伊斯组（Solimões Formation）多个遗址的化石记录。塔尔西芒（Talismã）遗址作为该组中最重要的脊椎动物化石遗址之一，产出了以鳄类、哺乳类和龟类为主的丰富多样的动物群，但小型脊椎动物的化石记录仍较为匮乏。本研究报道了从该遗址出土的若干孤立骨骼，这是巴西境内首次发现的新近纪无尾两栖类（anurans）化石记录。本次共识别出两个分类单元：一种独特的Pipa（负子蟾属）物种，以及一种未确定分类的Rhinella（真蟾蜍属）演化支物种，二者均为现存亚马孙两栖动物群的成员。这些新化石拓展了我们对该地区晚中新世无尾两栖类组合的认知，并为该遗址的古环境重建提供了新的支撑。