The Triassic predator lacked the ability to bite, as Saurosuchus could only bite with half the bite force of dinosaurs of the same size

Weak bite: Sauro suchus galilei, a seven-meter-long “terrestrial crocodile”, was at the top of the food chain 230 million years ago. However, Archosaurus had a relatively weak bite, as paleontologists have now discovered. According to this, the bite force of the Saurosuchus ranged from only 1015 to 1885 newtons, roughly half that of the similarly sized Allosaurus. Therefore, the researchers hypothesize that this primitive predator ate only soft meat and left the bones of its prey.

Although dinosaurs also lived in the Triassic period, 251 to 201 million years ago, the rulers of the world at the time were crocodile-like reptiles that occupied many ecological niches. However, it is interesting that some of the saucyria looked very similar to later groups of dinosaurs. For example, crocodilian Aetosaurs are reminiscent of the heavily armored Ankylosaurus of the Cretaceous period. And Loricata was a carnivore much like later predatory dinosaurs like Allosaurus.

Saurosuchus vs. Allosaurus

But do these similarities go beyond the physical aspects? Paleontologists led by Molly Fawcett of the University of Birmingham have now been able to establish this using Sarossuchus galilei, a seven-meter-long, 250-kilogram “terrestrial crocodile” that was at the top of the food chain some 230 million years ago. Because its skull closely resembled that of the later Allosaurus and the two were also about the same length, the researchers were able to compare primitive reptiles based on the strength of their bites.

To do this, paleontologists first reconstructed the almost completely preserved skull muscles of Saurosuchus from Argentina, and calculated the force with which the dinosaur could bite. Finally, they compared the specific value with the commonly assumed bite force of Allosaurus.

Large reptile, insignificant bite

“Our results show that the bite of Saurosuchus was surprisingly weak for an animal of this size,” says Fawcett and her colleagues. According to this, the jaws of the Triassic predator had a bite force of only 1015 to 1885 Newtons, which is comparable to the bite of today’s Javanese crocodiles.

For comparison: Allosaurus, which is about the same size, has a force of 3,572 Newtons, and Tyrannosaurus Rex even with 17,000 to 35,000 Newtons. All of today’s largest crocodilians, which are the closest living relatives of Saurosuchus, bite with much more force than Saurosuchus, with a force of about 16,000 newtons, the research team explains.

Sorosox left a relic

And Saurosuchus’ relatively modest bite also gives paleontologists clues about how the reptile ate the animals it killed. “It probably fed only on the soft, fleshy parts of its prey, because its bite could not crush bones,” explains Jordan Bestwick, a colleague of Fossett’s.

In doing so, the primitive predator may have also been doing something well for the smaller carnivores of its day, adds co-author Stephan Lautenschlager: “While Jurassic dinosaurs consumed most of their prey, Saurosuchus probably left behind fuller carcasses that were also suitable for scavengers.” Triassic that represents a meal” (The Anatomical Record, 2023; doi: 10.1002/ar.25299)

Source: University of Birmingham

August 22, 2023

– Anna Manz