Francischini Heitor, Dentzien-Dias Paula, Lucas Spencer G, Schultz Cesar L
Laboratório de Paleontologia de Vertebrados, Instituto de Geociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
Laboratório de Geologia e Paleontologia, Instituto de Oceanografia, Universidade Federal do Rio Grande, Rio Grande, Rio Grande do Sul, Brazil.
PeerJ. 2018 May 18;6:e4764. doi: 10.7717/peerj.4764. eCollection 2018.
Tetrapod tracks in eolianites are widespread in the fossil record since the late Paleozoic. Among these ichnofaunas, the ichnogenus is the most representative of the Permian tetrapod ichnological record of eolian deposits of Europe, North America and South America, where the Ichnofacies often occurs. In this contribution, we describe five sets of tracks (one of which is preserved in cross-section), representing the first occurrence of and in the "Pirambóia Formation" of southern Brazil. This unit represents a humid desert in southwestern Pangea and its lower and upper contacts lead us to consider its age as Lopingian-Induan. The five sets of tracks studied were compared with several ichnotaxa and body fossils with appendicular elements preserved, allowing us to attribute these tracks to dicynodonts and other indeterminate therapsids. Even though the "Pirambóia Formation" track record is sparse and sub-optimally preserved, it is an important key to better understand the occupation of arid environments by tetrapods across the Permo-Triassic boundary.
自晚古生代以来，风成岩中的四足动物足迹在化石记录中广泛存在。在这些遗迹化石群中，该遗迹属是欧洲、北美和南美二叠纪风成沉积四足动物遗迹学记录中最具代表性的，风成岩遗迹相在这些地区经常出现。在本论文中，我们描述了五组足迹（其中一组保存在横截面上），这代表了巴西南部“皮兰博亚组”中首次出现该遗迹属和另一遗迹属。该地层代表了泛大陆西南部的湿润沙漠，其上下接触关系使我们认为其时代为乐平世—印度阶。将所研究的五组足迹与几个遗迹分类单元以及保存有附肢元素的实体化石进行了比较，这使我们能够将这些足迹归属于二齿兽类和其他未确定的兽孔类。尽管“皮兰博亚组"的足迹记录稀少且保存欠佳，但它是更好地了解四足动物在二叠纪—三叠纪界线穿越干旱环境情况的重要关键。
