London: A new study suggests that the Tyrannosaurus rex did not need proper arms, because its head and neck were so powerful.
Tyrannosaurs, the family of big predatory dinosaurs that includes T. rex, had necks that were similar to those of modern birds.
So by studying how birds feed, Eric Snively of the University of Wisconsin-La Crosse and his colleagues were able to reconstruct how T. rex went about making a kill, New Scientist reported.
Snively placed electrodes on the skin of a dozen birds from 10 different species, ranging from domestic chickens to bald eagles. That allowed him to identify the precise muscle movements underlying each stage of feeding.
Snively found that the birds often raised their heads and fixed their vision on the prey before lowering their heads to attack.
T. rex had most of the same muscles, suggesting it could perform the same movements. That would also include raising its head, thrusting it upwards and pulling back with its legs once it has taken a bite.
Many of the birds also shook their necks, and the main muscle involved was found in the necks of tyrannosaurs.
The findings are published in the Journal of Zoology.
