Overview

• Researchers formally name Joaquinraptor casali from the Lago Colhué Huapi Formation near the Cretaceous–Paleogene boundary, identifying one of the latest known megaraptorans.
• The specimen is a well-preserved, partially articulated skeleton with a partial skull, vertebrae, ribs and powerful forelimbs featuring a 33 cm humerus.
• Bone histology records at least 19 growth lines indicating sexual maturity without full somatic maturity, with size estimates exceeding seven meters in length and one tonne in mass.
• A crocodiliform humerus pressed against the dinosaur’s lower jaw carries possible bite marks that suggest predation or scavenging, though the authors describe this inference as tentative.
• Phylogenetic analyses suggest megaraptorans align more closely with coelurosaurs as a potential sister group to tyrannosaurids, while sedimentology indicates a warm, humid near‑coastal habitat and an apex‑predator role in southern Patagonia.