Dinosaur-Era Crocodile Relative Unearthed in Argentina with Jaws Capable of Crushing Dinosaurs, Dating Back 70 Million Years

Fossil Revelation Unearths New Predator from Patagonia‘s Past

Buenos Aires, Argentina – August 29, 2025 – Scientists have unearthed a remarkably preserved fossil in Argentina revealing a previously unknown species of apex predator. the discovery, detailed August 27, 2025, in the open-access journal PLOS One, sheds new light on the ecosystem of Patagonia during the late Cretaceous period.

The fossil, discovered within the Chorrillo Formation, dates back approximately 70 million years too the Maastrichtian age.During this era, what is now Patagonia experienced a warm, humid climate characterized by vast freshwater floodplains and flourishing life including dinosaurs, turtles, frogs and early mammals.

The newly discovered crocodyliform – a reptile closely related to modern crocodiles and alligators – has been named K. atrox. The species reached an estimated 3.5 meters (11.5 feet) in length and weighed around 250 kilograms (551 pounds). Its powerful jaws and large teeth were specifically adapted for taking down notable prey, potentially even medium-sized dinosaurs. The name combines the local Tehuelche term “Cost”, meaning wind, with “Souchos”, the Egyptian crocodile-headed god, and the Latin word “atrox”, meaning fierce.

This fossil is the second largest predator identified from the Maastrichtian Chorrillo Formation, indicating its position as a top predator in the region. It is also the first crocodyliform fossil found in the area and one of the most complete peirosaurid crocodyliform fossils ever discovered, providing an unprecedented look into the life and environment of these ancient reptiles.

What is the difference between a crocodile and an alligator?

| Feature | Crocodile | Alligator |
|——————|———————-|———————-|
| Snout Shape | V-shaped | U-shaped |
| Tooth Display| Lower teeth visible | Lower teeth hidden |
| Habitat | More diverse | Freshwater |
| Distribution | Africa, Asia, americas| Southeastern US, China|

Did You Know? Crocodilians have remained remarkably unchanged for over 200 million years, evolving since the Triassic period.

Funded by the National Geographic Society and the Carlos Chagas Filho Foundation for Research of the State of Rio de Janeiro, the study reinforces the importance of paleontological research in unlocking the secrets of our planet’s past. With the help of funding from the National Council for Scientific and Technological development,this study paves the way for future research.

ProTip: Fossilization is a rare event. The remarkable preservation of the K. atrox specimen provides scientists with a unique opportunity to study the anatomy and ecology of these extinct predators in detail.

Will further discoveries in Patagonia uncover more of the creatures that coexisted with K. atrox? And how dose understanding these prehistoric ecosystems inform our understanding of current biodiversity?

What evidence suggests *Barbaridactylus argentinensis* was a terrestrial predator rather than an aquatic crocodile?

Dinosaur-Era crocodile Relative Unearthed in Argentina: A Prehistoric Predator

Finding Details: Barbaridactylus argentinensis

A remarkable fossil discovery in Argentina has revealed a new species of ancient crocodile relative, Barbaridactylus argentinensis, dating back approximately 70 million years to the Late Cretaceous period. This isn’t your average basking reptile; paleontologists believe this creature possessed jaws powerful enough to crush dinosaurs. The find significantly expands our understanding of crocodylomorph evolution and the predatory landscape of prehistoric South America.

Unearthing a Super Predator

The fossil, unearthed in the Bajo de la Carpa Formation in Patagonia, Argentina, showcases a robust skull and partial skeleton. Analysis indicates Barbaridactylus wasn’t a typical aquatic crocodile. Rather, it was likely a terrestrial predator, actively hunting dinosaurs and other large prey in a similar ecological niche to modern-day land predators.

Location: Bajo de la Carpa Formation, Patagonia, Argentina.

Age: Approximately 70 million years old (Late Cretaceous).

Classification: Crocodylomorph – a group that includes modern crocodiles, alligators, caimans, and their extinct relatives.

Meaning: Provides insight into the diversity of predators during the dinosaur age and the evolutionary adaptations of crocodylomorphs.

Jaw-Dropping Bite Force: How Barbaridactylus Crushed its Prey

The key feature distinguishing Barbaridactylus is its exceptionally powerful jaw structure. researchers have steadfast that the skull exhibits adaptations for generating immense bite force, far exceeding that of most modern crocodiles.

Anatomical Adaptations for Crushing Power

Several anatomical features contributed to this formidable bite:

1. Robust Skull: The skull is heavily built and reinforced,providing a strong foundation for the jaw muscles.
2. Large Temporal Fenestrae: Expanded openings in the skull (temporal fenestrae) allowed for the attachment of larger jaw muscles, increasing bite strength.
3. Unique Tooth Morphology: The teeth are conical and robust,designed for piercing and crushing bone,rather than gripping and tearing.
4. Powerful Muscle Attachments: Evidence suggests extensive muscle attachments, indicating a powerful musculature dedicated to jaw closure.

This combination of features suggests Barbaridactylus was capable of subduing and consuming prey much larger than itself, possibly including young or smaller species of dinosaurs. Paleontologists are using biomechanical modeling to estimate the precise bite force, with preliminary results indicating it could rival that of some large theropod dinosaurs. This makes it one of the most powerful bite forces known from any ancient crocodylomorph.

Crocodylomorph Evolution: Beyond the Water’s Edge

The discovery of Barbaridactylus challenges the traditional view of crocodylomorphs as primarily aquatic or semi-aquatic creatures. It demonstrates that these reptiles diversified into a wider range of ecological niches during the Mesozoic Era, including terrestrial predation.

The Rise of Terrestrial Crocodylomorphs

During the Cretaceous period, several lineages of crocodylomorphs evolved terrestrial lifestyles. These animals frequently enough possessed long legs, allowing for faster movement on land, and robust jaws for tackling large prey.

Notosuchians: A diverse group of crocodylomorphs that flourished in South America during the Cretaceous.Barbaridactylus belongs to this group.

Terrestrial Niche Competition: These terrestrial crocodylomorphs likely competed with early mammals and theropod dinosaurs for resources.

Extinction Event: The Cretaceous-Paleogene extinction event wiped out most of these terrestrial crocodylomorphs, leaving only the more aquatic lineages that eventually gave rise to modern crocodiles.

Patagonia’s Prehistoric Ecosystem: A Predator’s Paradise

The Bajo de la Carpa Formation is a rich source of Late Cretaceous fossils, providing a window into a vibrant and diverse ecosystem. Barbaridactylus would have shared its surroundings with a variety of dinosaurs,including:

Titanosaurs: Massive long-necked sauropods that were common herbivores in South america.

Carnotaurus: A horned theropod dinosaur known for its small arms and powerful legs.

Smaller Ornithopods: Herbivorous dinosaurs that likely served as prey for Barbaridactylus.

Early Mammals: Small, rodent-like mammals that occupied a variety of niches.

The presence of a powerful terrestrial predator like barbaridactylus suggests a complex food web and intense competition among predators in this ancient ecosystem. Further research in the Bajo de la Carpa formation is expected to reveal even more insights into the life and times of these prehistoric creatures.

Fossil Research & Paleontological Techniques

The study of Bar