A team of paleontologists has unearthed the fossil remains of a previously unknown genus and species of a prehistoric crocodile with exceptionally preserved abdominal contents that have revealed that the last meal of this creature, named Confractosuchus sauroktonos , was a juvenile ornithopod dinosaur, a young herbivorous biped.
Confractosuchus sauroktonos lived in what is now Queensland, Australia, about 95 million years ago during the Late Cretaceous. It is an ancestor of today’s crocodiles.
The fossilized bones, a nearly complete skull with dentition and a postcranial skeleton missing its tail and upper limbs, were recovered from a sheep station near the northwestern margins of the Winton Formation, a well-known Australian geological deposit.
The research was led by Matt White, a research associate at the Australian Museum of the Age of Dinosaurs, through the University of New England, in collaboration with the Australian Nuclear Science and Technology Organization (ANSTO).
“At the time of his death, this freshwater crocodile was around 2.5 meters long and still growing ,” explains White. “While Confractosuchus would not have specialized in eating dinosaurs, it would not have missed an easy meal, such as the remains of young ornithopods found in its stomach.”
A milestone in paleontology
Although the crocodile was not as big as we might imagine (2.5 meters long, we have already seen), even by modern standards and the dinosaur, the prey, was barely the size of a chicken, the find is still extraordinary. , since it is the first time that it occurs and confirms what paleontologists have suspected for quite some time. It is the first evidence of crocodile and dinosaur predation in Australia.
The discovery also suggests that dinosaurs were an important part of the Cretaceous food web, as many were not found at the top of the food chain.
And it is that, for the researchers, who publish their work in the journal Gondwana Research, the discovery was quite a surprise: while putting together the pieces of the fossilized crocodile, they noticed the partial remains of a young ornithopod dinosaur inside its stomach. Finding gut contents from a Cretaceous crocodile is an extremely rare find and only a few examples of dinosaur predation are known from around the world.
“Together, the ornithopod remains comprise three dorsal vertebrae, two sacral centra, three distal caudal centra, both proximal femurs, left tibia, and other elements; all presumably from a single individual. These gut contents strangely represent the earliest recorded skeletal remains of ornithopods from the Winton Formation and may represent a new species ,” the authors clarify.
However, the ornithopod is too incomplete to be identified at this time. What they have been able to elucidate is that at the time of its death, the ornithopod was a young dinosaur and weighed between 1-1.7 kg . Depending on the arrangement of the bones, C. sauroktonos either directly killed the animal with a fatal bite or quickly devoured it after death. One of his femurs received such a colossal bite that there is still a tooth mark on the surface of the bone. The other femur was cut in half.
For all that, however, the crocodile was probably not a dinosaur specialist. “Though it wouldn’t have missed an easy meal, like the remains of young ornithopods found in its stomach,” White says.
Why the prehistoric crocodile died shortly after gobbling up this young dinosaur is a mystery . The fact that the crocodile’s tail has not been found suggests that a larger dinosaur may have done the same to this delicious morsel (according to experts, the tail would be the tastiest part of a crocodile).
Given the lack of comparable global specimens, this prehistoric crocodile and its last meal will continue to provide us with clues about the relationships and behaviors of animals that inhabited Australia millions of years ago.
The fossilized remains of C. sauroktonos are on display at the Australian Museum of the Age of Dinosaurs in western Queensland.
Referencia: Matt A. White et al. Abdominal contents reveal Cretaceous crocodyliforms ate dinosaurs. Gondwana Research, published online February 10, 2022; doi: 10.1016/j.gr.2022.01.016
