This work aimed to investigate the ichnofossiliferous sites in Nioaque and surrounding region, Mato Grosso do Sul state, Brazil, analyzing their paleontological, stratigraphic and paleoenvironmental context, because dinosaur tracks were found in an area previously mapped as Permo–Carboniferous age. Some sedimentary facies previously assigned to the glacial Aquidauana Formation were herein reinterpreted as part of the basal section of the Botucatu Formation (Late Jurassic/Early Cretaceous) and include floodplain and residual channel deposits, possibly representing the lower half of this formation's sequence in the studied area. The ichnofossils that have been found include both isolated tracks of Theropoda and Ornithopoda, a trackway of Eubrontes isp., a vertebrate burrow and invertebrate traces (Palaeophycus) possibly related to the Entradichnus ichnofacies. Sedimentological interpretation suggests the existence of a river system just before the deposition of the typical Botucatu eolian facies in this region. This is the first documented record of fluvial deposits transitionally to the traditional eolian Botucatu Formation. Noteworthy, the dinosaur tracks have played a key role for the interpretation of these rocks as Botucatu Formation and for better understanding the whole system due to the impossible Paleozoic age (dinosaur tracks).

这项工作旨在调查巴西南马托格罗索州南欧亚克及周边地区的鱼类化石部位，分析其古生物学，地层学和古环境背景，因为恐龙的踪迹是在以前被映射为二叠纪-石炭纪的地区发现的。在此，将先前分配给冰川阿基多瓦纳组的一些沉积相重新解释为Botucatu组基础段的一部分（侏罗纪晚期/早白垩世），包括洪泛区和残余河床沉积物，可能代表了该研究中该组层序的下半部分。区域。发现的鱼类化石包括Theropoda和Ornithopoda的孤立痕迹，Eubrontes isp。的痕迹，脊椎动物的洞穴和无脊椎动物的痕迹（古生物（Paleeophycus）可能与中华古生虾（ Entradichnus ichnofacies）有关。沉积学解释表明，在该地区典型的Botucatu风沙相沉积之前，就存在河流系统。这是河床沉积过渡到传统风成岩Botucatu组的第一个文献记录。值得注意的是，由于不可能的古生代时代（恐龙足迹），恐龙足迹对于将这些岩石解释为Botucatu组起了关键作用，并且对于更好地理解整个系统起了关键作用。