Muttaburrasaurus langdoni Was a Selective Dinosaur Eater

Most people imagine dinosaurs as either ferocious predators or sluggish plant-eaters that munched on whatever was in front of them. Yet one Australian dinosaur, Muttaburrasaurus langdoni, does not neatly match that straightforward view.

This enormous animal appears to have favoured particular foods and possessed the means to locate them precisely.

Around 96 million years ago, Muttaburrasaurus travelled across what is now central Australia. Scientists had long presumed that it lived much like numerous other dinosaurs that ate plants.

However, recent research presents a contrasting view. Rather than being simply another grazer, it may have selectively chosen certain plants and perhaps occasionally added small animals to its diet.

Muttaburrasaurus langdoni’s nose

New fossil material has prompted researchers to reassess this dinosaur’s facial features, particularly its nose and mouth. Previous reconstructions proposed that it had a toothless beak, comparable with familiar plant-eating dinosaurs from elsewhere in the world. Closer examination showed that this idea was incorrect.

Dr Matthew Herne, the study’s lead author at the University of New England, described the team’s discovery.

“This was unexpected, because the beak (front part of the snout) of Muttaburrasaurus was thought to be toothless like many other well-known plant-eating species such as Iguanodon from Europe and the ‘duck-billed’ Hadrosaurs, mostly found in the Northern Hemisphere,” Herne explained.

“But ornithischian dinosaurs of this size normally have beak-like snouts without teeth, with a good example of this being Triceratops,” he continued.

Rather than a smooth beak, the dinosaur possessed teeth at the very front of its snout. This seemingly minor feature is significant.

A slim beak edged with teeth could have enabled it to pick out particular leaves and seeds instead of taking whatever was close by. It might also have consumed invertebrates on occasion.

Built to navigate by smell

The most striking characteristic of Muttaburrasaurus langdoni is its rounded, bulbous nose. Its purpose was uncertain for many years, but the latest study offers a more defined explanation for this feature.

Researchers identified sizeable air spaces within the skull, positioned above the principal air passage. These spaces probably slowed air as it entered, allowing odour molecules longer to be detected. This suggests a highly developed sense of smell.

Its brain provides further support for this interpretation. The olfactory bulbs, which handle smell, are among the largest recorded in any dinosaur.

“So we suspect that they indicate a very acute sense of smell, perhaps to help the animal find food, detect predators or assist in directional navigation,” explains Dr Herne, who is also affiliated with Queensland Museum and Australian Age of Dinosaurs Museum of Natural History in Queensland.

It was therefore not merely a passive feeder. It probably used smell to locate the most suitable food and remain vigilant for threats.

Standing upright when necessary

The skull provided evidence beyond its feeding behaviour, also revealing potential details about how the animal moved. Researchers examined the inner ear and the imprint left by the brain to assess its posture and balance.

“We realised that its inner ear was more like dinosaurs that walked on two legs, like Tyrannosaurus rex, than others that spent more time on all fours,” says Professor Vera Weisbecker from Flinders University.

“So it’s possible that Muttaburrasaurus was a large herbivore walking and running on its hind legs when needed and used its front arms for support to crop food closer to the ground.”

This combination of locomotion indicates adaptability. It may have risen upright to move about or flee danger, before lowering its body to eat.

Muttaburrasaurus langdoni and water

The setting inhabited by Muttaburrasaurus also influenced its way of life. Geological findings indicate that it remained near the inland Eromanga Sea, which covered extensive areas of Australia from roughly 140 million to 90 million years ago.

Living in coastal environments may have affected what it ate. Scans of its nasal passages indicate that it possessed salt glands.

Such glands may have expelled surplus salt from its food, an advantageous adaptation if it fed on vegetation growing in saline conditions or even small crustaceans along the shoreline.

Its teeth provide an additional clue. They were adapted to grind food rather than cut through it, much like the teeth modern cows and horses use to process resilient plant matter.

Eyes positioned at the sides

The form of its eye sockets indicates that Muttaburrasaurus langdoni had a broad sideways field of view. It probably had limited vision immediately ahead of its face. This sort of sight is useful for detecting danger approaching from numerous directions.

This arrangement could have helped it remain watchful in exposed landscapes. It is still unknown whether it lived in groups, as scientists do not yet have sufficient evidence to establish herd behaviour.

Muttaburrasaurus langdoni’s family tree

The findings also allow Muttaburrasaurus to be placed more precisely among related dinosaurs. Its toothed beak indicates that it diverged earlier than other ornithopod dinosaurs.

This characteristic links it with more ancient species that likewise had teeth at the front of their snouts.

Sophisticated imaging was central to these results. Dr Joseph Bevitt of the Australian Nuclear Science and Technology Organisation (ANSTO) said that modern techniques enabled the team to create detailed 3D models of the skull, jaws and teeth. Those models exposed features that earlier techniques may have overlooked.

The further scientists investigate this dinosaur, the more distinctive it appears. It was not simply another plant-eater wandering through ancient Australia.

Instead, it had its own methods of locating food, travelling through its surroundings and using the resources available to it.

The complete study was published in the journal PeerJ.