Hadrosaurs, or duck-billed dinosaurs, weighed up to 8,000 pounds and had long necks, yet they were still able to move around efficiently. According to a study published in PLOS ONE, these dinosaurs were able to support their massive size due to a unique trabecular bone structure. The trabecular, or spongy bone tissue in hadrosaurs’ interior bones increased in density as the dinosaur’s body size increased, rather than the trabecular bone thickness increasing like in mammals and birds. This allowed the hadrosaurs’ skeletal structure to remain lightweight while still providing sufficient support.
The researchers, including paleontologist Tony Fiorillo, analyzed CT scans of hadrosaur fossil bones and compared them to scans of living elephants and mammoths. They found that the trabecular architecture in hadrosaurs differed significantly from other creatures, enabling them to carry their large body weight with “great difficulty moving.” As mechanical engineering Ph.D. Trevor Aguirre states:
The idea for this study originated a decade earlier when biomedical engineer Seth Donahue demonstrated how engineering theories and CT scans could analyze bone structure in modern animals. Learning of Donahue’s approach inspired Fiorillo and colleagues to apply a similar methodology to dinosaur fossils, yielding new insights into dinosaurs’ unique adaptation to their massive size.
In summary, the researchers concluded that hadrosaurs’ ability to support up to 8,000 pounds stemmed from a trabecular bone pattern that increased in density rather than thickness as the dinosaurs grew, making their skeletons lightweight yet sturdy enough for their large biomechanical loads.
