Centro de Ciências da Natureza, Universidade Federal do Piauí, 64049-550 Teresina, Brazil.
Proc Natl Acad Sci U S A. 2012 Jan 31;109(5):1584-8. doi: 10.1073/pnas.1115975109. Epub 2012 Jan 17.
The medial Permian (~270-260 Ma: Guadalupian) was a time of important tetrapod faunal changes, in particular reflecting a turnover from pelycosaurian- to therapsid-grade synapsids. Until now, most knowledge on tetrapod distribution during the medial Permian has come from fossils found in the South African Karoo and the Russian Platform, whereas other areas of Pangaea are still poorly known. We present evidence for the presence of a terrestrial carnivorous vertebrate from the Middle Permian of South America based on a complete skull. Pampaphoneus biccai gen. et sp. nov. was a dinocephalian "mammal-like reptile" member of the Anteosauridae, an early therapsid predator clade known only from the Middle Permian of Russia, Kazakhstan, China, and South Africa. The genus is characterized, among other features, by postorbital bosses, short, bulbous postcanines, and strongly recurved canines. Phylogenetic analysis indicates that the Brazilian dinocephalian occupies a middle position within the Anteosauridae, reinforcing the model of a global distribution for therapsids as early as the Guadalupian. The close phylogenetic relationship of the Brazilian species to dinocephalians from South Africa and the Russian Platform suggests a closer faunistic relationship between South America and eastern Europe than previously thought, lending support to a Pangaea B-type continental reconstruction.
中二叠世（约 2.70-2.60 亿年前：瓜达卢佩期）是脊椎动物重要的演化更替时期，尤其是反映了从盾皮鱼类到合弓类的更替。到目前为止，关于中二叠世四足动物分布的大部分知识来自于南非卡鲁和俄罗斯地台上发现的化石，而泛古陆的其他地区仍然知之甚少。我们根据一个完整的头骨，为来自南美的中二叠世陆生肉食性脊椎动物的存在提供了证据。Pampaphoneus biccai gen. et sp. nov. 是一种兽孔目“似哺乳爬行动物”，属于 anteosauridae，是一种早期合弓类掠食者，仅在俄罗斯、哈萨克斯坦、中国和南非的中二叠世有记录。该属的特征包括眶后骨结节、短而球状的后犬齿和强烈弯曲的犬齿。系统发育分析表明，巴西兽孔目位于 anteosauridae 的中间位置，这一结果强化了早在瓜达卢佩期合弓类动物就具有全球分布的模型。巴西物种与来自南非和俄罗斯地台的兽孔目动物的密切亲缘关系表明，南美洲和东欧之间的动物区系关系比以前认为的更为密切，支持盘古大陆 B 型大陆重建的观点。
