A digital reconstruction of the world’s largest known land animal, the Cretaceous dinosaur Argentinosaurus, has allowed it to take its first steps -- albeit virtually -- in over 94 million years.
The recreation, outlined in PLoS ONE, is the most anatomically detailed walking simulation so far for a dinosaur, according to the researchers. The study also provides the first ever virtual trackway for Argentinosaurus.
The skeleton used in the study shows that the plant-eating dinosaur measured at least 131 feet long. The reconstruction reveals that it lumbered along at around 5 miles per hour.
“The simulation shows a slow walking gait, which is to be expected, given that the animal weighs 80 tonnes,” lead researcher Bill Sellers from the University of Manchester’s Faculty of Life Sciences, told Discovery News. “What is interesting is how well the simulated footfall pattern matches up with typical sauropod trackways.”
For the study, Sellers and his colleagues laser scanned the huge dinosaur’s skeleton. They then used an advanced computer modeling system (Sellers has his own software called Gaitsym) that involves the equivalent of 30,000 desktop computers. It virtually recreated the dinosaur, including the sauropod’s movements.
The discovery that Argentinosaurus could walk counters prior speculation that the animal could not have done so, based on previous estimations of its size.
This latest research concludes not only that Argentinosaurus could walk, but that it was also at the top of its food chain.
“Once you hit 80 tonnes, you don’t have to worry about being eaten by predators,” Sellers explained. “We don’t know whether this animal used its long neck to graze over wide areas of low-laying vegetation or for reaching the tops of trees, but from its locomotion we know that it was a slow, steady mover.”
Argentinosaurus eggs, however, were no bigger than those of many dinosaurs and large birds. It's therefore likely that Argentinosaurus young were fairly small and would have been easy prey for other carnivorous species that lived along the Cretaceous planes of what is now Patagonia, South America.
Understanding how such past animals moved may help us to better understand modern day musculoskeletal systems.
“If you are trying to understand any body system that is shared by a range of different animals then it is often extremely useful to compare this system across different species,” Sellers explained. “Vertebrate muscles, skeletons and joints work exactly the same way in everything from fish to humans.”
He continued, “The really interesting aspect of dinosaur locomotion is that you are looking at animals that test the limits of the musculoskeletal system simply by virtue of being so big. They have to make compromises and come up with ways of coping that help us to understand the limits and compromises in the human musculoskeletal system.”
Phillip Manning is head of the Paleontology Research Group at the University of Manchester and is a research associate at the American Museum of Natural History.
Manning told Discovery News that paleontology is now undergoing a renaissance, with more interdisciplinary approaches, such as this, helping to solve long-standing questions.
“To carefully break down the key components of the locomotion of such vast animals as Argentinosaurus is allowing us greater insight to the biology and physiology of such vast organisms,” Manning said. “The diverse plethora of techniques and technology available to paleontology today is changing the way we study and interpret the fossil record.”
In the future, the researchers plan to digitally recreate other dinosaurs, such as Triceratops, Brachiosaurus and Tyrannosaurus rex, in order to better understand their movements. Prior simulations of duck-billed hadrosaurs uncovered novel gaits, so Sellers joked that “running, skipping and jumping may well turn up.”