Overview

• PLOS One formally describes Kostensuchus atrox from Argentina’s Maastrichtian Chorrillo Formation, based on an articulated skull, jaws and partial postcranial skeleton recovered near El Calafate.
• Researchers estimate a length of roughly 3–3.5 meters and a mass near 250 kilograms, with a high, broad snout, deep adductor chamber, robust forelimb anatomy and serrated teeth indicating large‑prey hunting.
• The specimen represents the first crocodyliform recorded from the Chorrillo Formation and one of the most complete peirosaurids known, pointing to a land‑capable top predator that likely targeted medium‑sized dinosaurs.
• Phylogenetic analyses place the species among robust, broad‑snouted peirosaurids alongside Colhuehuapisuchus from Patagonia and Miadanasuchus from Madagascar, extending southernmost records for the group.
• The open‑access study, led by scientists from Argentina with collaborators in Portugal and Japan, highlights remaining gaps in hindlimb material that limit detailed locomotion inferences.