A Neuquensaurus australis (Dinosauria: Sauropoda) dominated bone accumulation (Anacleto Formation, Campanian, Patagonia): burial process, preliminary biostratinomic insights and palaeoecological implications

A bone-bearing assemblage dominated by the saltasaurine Neuquensaurus australis from the Anacleto Formation (Campanian, Patagonia, Argentina) is analysed from a biostratinomic and sedimentological perspective. The assemblage comprises a minimum of six individuals (five subadults and one juvenile), with rare remains referable to Titanosauria indet. and teeth of Theropoda indet. Biostratinomic evidence, including low weathering, negligible abrasion, rare bioerosion, and a balanced representation of elements with different transport susceptibilities, indicates limited exposure, minimal reworking, and short transport prior to burial. The near-monospecific composition, preservation of fragile elements, lack of preferred orientation and hydraulic sorting collectively support a rapid burial, likely triggered by a dense, sediment-laden flow associated with an episodic flooding event. The assemblage is interpreted as an event-dominated accumulation, most likely reflecting a non-catastrophic mortality event involving multiple individuals belonging to two ontogenetic categories (one juvenile and five subadult individuals), followed by rapid entombment. Rare non- Neuquensaurus remains are regarded as a minor attritional background signal, indicating limited time-averaging of the assemblage.