Andrade-Silva, Murilo ， Francischini, Heitor
2026-09-01 JOURNAL OF SOUTH AMERICAN EARTH SCIENCES 2026 181(卷), null(期), (null页)
The Lower Cretaceous Botucatu Formation (Parana Basin, Brazil) preserves one of the largest erg systems in Gondwana, but lacks vertebrate body fossils, making trace fossils the only evidence of its terrestrial fauna. This study presents a reassessment of putative lacertoid tracks using photogrammetry and morphometric analyses. Four specimens were examined to refine their ichnotaxonomic identity and evaluate possible trackmakers. Most tracks are poorly preserved, appearing as shallow, oval depressions without diagnostic features such as digit impressions. Comparisons with lacertoid and crocodylomorph ichnotaxa reveal significant morphological and locomotor inconsistencies, including the absence of key lacertoid traits. Wide variation in pace angulation (68.09 degrees-157.96 degrees) and the presence of marginal expulsion rims indicate strong control by substrate properties and locomotion on dune slopes. These tracks cannot be confidently assigned to any ichnotaxon and are better interpreted as substrate-related artifacts. This study highlights the importance of integrating ichnotaxonomy with sedimentological and taphonomic analyses in desert ichnofaunas.