Vertebrate taphonomy of the Ischigualasto Formation

A comprehensive analysis of vertebrate taphonomy in the Ischigualasto Formation reveals distinct preservation trends linked to sedimentary facies and stratigraphic position, reflecting basin evolution and paleoclimate. Fossils are predominantly concentrated along basin margins, with floodplain deposits preserving 88% of occurrences, ranging from unidentifiable fragments to articulated skeletons. Coarser-grained fluvial channel deposits account for 12%, including well-preserved cynodont skulls. The basal La Peña Member shows highly weathered, disarticulated fossils with hematitic permineralization, while the overlying Cancha de Bochas Member (65% of occurrences) features calcite-permineralized remains from isolated bones to complete skeletons. The Valle de la Luna Member preserves a unique association of vertebrate and plant fossils under wetter conditions, marked by superficial and penetrating hematite precipitation. The uppermost Quebrada de la Sal Member is nearly barren of fossil remains.

Colombi, C. E., Rogers, R. R., & Alcober, O. A. (2012). Vertebrate taphonomy of the Ischigualasto Formation. Journal of Vertebrate Paleontology, 32(sup1), 31–50. https://doi.org/10.1080/02724634.2013.809285