Prehistoric megaraptor species unearthed holding its final meal before death 68 million years ago

An artist’s illustration shows Joaquinraptor feasting on a crocodile. (Image: (Andrew McAfee, Carnegie Museum of Natural History)

A new fossil find in Argentina is rewriting what we know about ancient predators. Deep in Patagonia’s prehistoric past, a raptor-like dinosaur prowled the land, and scientists believe it had a surprising meal on its menu.

What is Joaquinraptor and how big was it?
Palaeontologists in Argentina have identified a new species of megaraptor dinosaur named Joaquinraptor casali. This predator wandered the area approximately 68 million years ago and increased more than seven metres in length from snout to tail.

It probably weighed more than 1,000 kilograms and utilized its bulk and power to dominate the Late Cretaceous environment. With tyrannosaurs nowhere to be seen in the southern hemisphere, megaraptors such as Joaquinraptor took the position of apex predator in old South America and Australia.

What is the evidence that it fed on crocodiles?

Scientists found a humerus bone stuck between the lower jaws of Joaquinraptor that they think is from a crocodyliform. The bone bore tooth marks and was even touching some of the dinosaur’s teeth, offering a rare clue about its diet. Lucio Ibiricu, a palaeontologist at the Patagonian Institute of Geology and Palaeontology (IPGP), told ScienceAlert that this suggests the megaraptor might have been feeding on the ancient crocodile when it died.

Some experts caution that the bone could have been washed into the dinosaur’s mouth after death. However, the presence of tooth marks makes a direct encounter between predator and prey far more likely. It is also possible the two creatures clashed over other food sources before one ended up as a meal.

The megaraptor jaw and the crocodyliform leg bone preserved in their original discovery position (Image: Ibiricu et al., Nat. Commun. 2025)

How old was this predator and what else was found?
Analysis of the microstructure of a tibia fragment revealed that the Joaquinraptor specimen was at least 19 years old. It was sexually mature but not fully grown, according to Ibiricu, who explained that the age estimate was based on growth lines preserved in the bone. Despite the fossil being incomplete, with parts of the skull, jaws, limbs and tail vertebrae unearthed, it remains one of the most complete megaraptor specimens ever discovered.

Why is this discovery significant for dinosaur evolution?
The find helps fill gaps in our understanding of megaraptor evolution and their role as top predators. Unlike the massive, power-driven tyrannosaurs of the north, megaraptors developed strong forelimbs and enlarged claws, which scientists believe were used for tearing soft tissue and capturing prey. “Megaraptorids, among other aspects, are characterised by powerfully developed forelimbs equipped with hypertrophied claws,” Ibiricu told ScienceAlert. “So its claws may have played an important ecological role.”

The discovery of Joaquinraptor also shows that megaraptors thrived until the end-Cretaceous extinction event. Had that cosmic catastrophe not occurred, their reign as apex predators might have continued even longer.

What are the implications for future research?

This fossil not only adds a new species, but also records extremely rare evidence of predator-prey interaction in the Late Cretaceous. It may redefine the way scientists think about megaraptor behaviour, feeding habits and their evolutionary history. With every find, the history of these formidable predators becomes more clear, providing a glimpse into a bygone world where speed, claws and brains dominated the ancient food chain.

The research on the finding was published in Nature Communications.