{"id":361,"date":"2025-08-27T13:04:07","date_gmt":"2025-08-27T20:04:07","guid":{"rendered":"https:\/\/scienceblog.com\/wildscience\/?p=361"},"modified":"2025-08-27T13:04:07","modified_gmt":"2025-08-27T20:04:07","slug":"fierce-crocodile-relative-hunted-dinosaurs-in-patagonia","status":"publish","type":"post","link":"https:\/\/scienceblog.com\/wildscience\/2025\/08\/27\/fierce-crocodile-relative-hunted-dinosaurs-in-patagonia\/","title":{"rendered":"Fierce Crocodile Relative Hunted Dinosaurs in Patagonia"},"content":{"rendered":"

A terrifying predator lurked in prehistoric Patagonia. A newly described species, Kostensuchus atrox<\/em>, stretched 11.5 feet long, weighed about 250 kilograms, and likely dined on dinosaurs. Unearthed near El Calafate, Argentina, the exquisitely preserved fossil reveals a broad-snouted, hypercarnivorous crocodyliform that roamed the Chorrillo Formation floodplains about 70 million years ago, just before the mass extinction of the dinosaurs. Published in PLOS One<\/a>, the study identifies this peirosaurid as one of the top predators of the Late Cretaceous ecosystem, second only to the giant megaraptorid theropod Maip<\/em>.<\/p>\n

A Predator Built for Power<\/h2>\n

The skull of Kostensuchus atrox<\/em> measures nearly half a meter long, with conical, ziphodont teeth designed for puncturing and slicing flesh. Unlike modern crocodiles, which are mostly ambush predators in water, this crocodyliform seems to have been a terrestrial powerhouse. Its robust jaws and deep lower mandible suggest crushing bite forces, while a stout humerus points to strong, grasping forelimbs.<\/p>\n

“The new specimen reveals, for the first time, the anatomy and body plan of a large and broad snouted peirosaurid,” the authors write in PLOS One<\/a>.<\/p><\/blockquote>\n

By body mass alone, Kostensuchus<\/em> dwarfed many other crocodyliforms of its time, which often weighed under 60 kilograms. This sheer size, coupled with knife-edged teeth, implies an apex role in Patagonia’s predator guild, capable of taking down mid-sized ornithischian dinosaurs as well as mammals and reptiles that shared its floodplain habitat.<\/p>\n

Patagonia\u2019s Prehistoric Neighborhood<\/h2>\n

The Chorrillo Formation, a stretch of sedimentary rocks deposited near the end of the Cretaceous, paints a vivid picture of life in southern Patagonia 70 million years ago. It held titanosaurs like Nullotitan<\/em>, megaraptorids like Maip<\/em>, armored ankylosaurs, early birds, frogs, turtles, and even monotremes. Into this mix came Kostensuchus atrox<\/em>, whose name fuses “Kosten,” the Aonikenk word for the fierce Patagonian wind, with “Souchos,” the crocodile-headed Egyptian deity.<\/p>\n

This predator now stands as the first crocodyliform known from the formation, and its discovery fills a missing piece in the puzzle of South America’s ancient food webs. Unlike northern Patagonia, dominated by abelisaurid theropods, the southern ecosystems balanced megaraptorids with these broad-snouted crocodyliforms.<\/p>\n

Key Findings<\/h2>\n