Kostensuchus atrox strolled Earth throughout the Maastrichtian age of the Cretaceous duration, around 70 million years earlier.

The ancient types was a big predator, around 3.5 m(11.5 feet) long and 250 kg in weight.

The animal had a large, effective jaw and huge teeth efficient in feasting on big victim, most likely consisting of medium-sized dinosaurs.

Kostensuchus atrox came from Peirosauridae, a Gondwanan household of crocodylomorphs within the suborder Notosuchia.

“This brand-new types comes from the notosuchian clade Peirosauridae, representing the most recent and southernmost record for this group of crocodyliforms,” stated Dr. Fernando Novas, a paleontologist at the Museo Argentino de Ciencias Naturales ‘Bernardino Rivadavia,’ and his associates.

The fossilized skull and bones of Kostensuchus atrox were discovered in the Chorrillo Formation, about 30 km south-west of the town of El Calafate in the province of Santa Cruz.

“The Chorrillo Formation formed around 70 million years back,” the paleontologists stated.

“At this time, southern Patagonia was a warm, seasonally damp landscape of freshwater floodplains, home to animals like dinosaurs, turtles, frogs, and different mammals.”

“The brand-new fossil uncovered in this development is mainly undamaged, consisting of a skull and jaws with noticeable information, along with several bones from the body.”

Kostensuchus atrox is the second-largest predator understood to researchers from the Chorrillo Formation, and was most likely among the leading predators in the area.

The brand-new types is likewise the very first crocodyliform fossil discovered in this development, and among the most undamaged peirosaurid crocodyliforms ever discovered, offering researchers special brand-new insight into these ancient animals and their community.

“The discovery of Kostensuchus atrox substantially broadens the understanding about the anatomy of broad-snouted peirosaurids, formerly understood from very fragmentary remains from South America and Madagascar,” the scientists stated.

“The brand-new physiological details clarifies both, the resemblances and distinctions in between broad-snouted peirosaurids and baurusuchids, the other crocodyliform clade that individually progressed into peak predators throughout the Cretaceous of Gondwana.”

Kostensuchus atrox formed part of the most recent Cretaceous environment of southern Patagonia, in a freshwater community under a temperate to warm environment with seasonal humidity, along with a varied animals of dinosaurs, mammals, and other vertebrates,” they included.

“The broad and high snout of Kostensuchus atroxwith especially big and robust ziphodont teeth, together with a broad adductor chamber in the skull and deep mandibular ramus, and robust forelimb anatomy recommends that the brand-new types can suppressing big victim.”

“These functions suggest that Kostensuchus atrox played the function of a leading predator within this end-Cretaceous community.”

The discovery of Kostensuchus atrox is explained in a paper released today in the journal PLoS ONE

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F.E. Novas et al2025. A brand-new big hypercarnivorous crocodyliform from the Maastrichtian of Southern Patagonia, Argentina. PLoS One 20 (8 ): e0328561; doi: 10.1371/ journal.pone.0328561