An artist’s reconstruction of Argentinosaurus, one of the largest ever dinosaurs
Mohamad Haghani / Alamy
Dinosaurs could count the largest animals to ever walk the Earth among their scaly and feathery ranks. According to a new study, the very nature of their bones may have allowed them to attain stupendous sizes.
The largest dinosaurs of all time, such as the long-necked herbivore Argentinosaurus, were more than 30 metres in length and weighed more than 50 tonnes. They were far larger than any land-dwelling mammal. Other giants included the Tyrannosaurus rex, a 12-metre, 8-tonne carnivore that far surpassed the largest polar bear.
Laying eggs instead of carrying live young allowed dinosaurs to avoid some biological constraints that determine mammalian size. Yet a study by Seth Donahue at the University of Massachusetts Amherst and his colleagues proposes that differences between mammal and dinosaur bone tissue also had a role to play.
The analysis focuses on trabecular bone, a type of spongy-looking material often found at the ends of bones like the femur. “Trabecular bone is an exceptional, lightweight structural material,” says Donahue. Until now, no one had studied the properties of this bone tissue in dinosaurs. The focus on trabecular bone makes the new study unique, says Sandra Shefelbine at Northeastern University in Massachusetts, who wasn’t involved in the work.
By combining detailed scans of bone tissue with an engineering technique called finite element analysis, the researchers detected that trabecular bone in dinosaurs is organised differently than in mammals, so as to be less dense without sacrificing strength.
“I think the findings do have implications for understanding how dinosaurs were able to support gigantic body sizes not seen in animals today,” says Donahue. The analysis suggests that it may be useful to look to dinosaur bone for inspiration when designing things that require lightweight strength, such as a bridge or space shuttle.
Journal reference: PLoS One, DOI: 10.1371/journal.pone.0237042
More on these topics: