We’re the first to admit we wouldn’t want to pick a fight with a Tyrannosaurus rex – the czar of the dinosaur kingdom is renowned for its pulverizing bite, impressive stature, and apparently, lightness of foot. And yet, according to a paper published in the Proceedings of the Royal Society B, it might not have proved much of a match for the humble Galapagos ground finch.
OK, so T. rex still has size on its side. But gram-for-gram, the finch has the edge when it comes to biting power, packing a punch at 70 Newtons despite weighing just 33 grams. In comparison, the bite of a T. rex is 57,000 Newtons, which sounds like a lot but is actually distinctly average for a creature of its size (8 tonnes). That means that if you were to shrink a T. rex to the size of the finch (or enlarge a finch to the size of a T. rex), the bird will have a biting force 320 times as powerful as the dinosaur.
What’s more, it developed this special ability on a much faster timescale than the mighty T. rex. Less than a million years, to be exact, compared to tens of millions.
“The proclaimed 'King of the Dinosaurs' would be no match for a finch in a fight, if they were the same size,” co-author Chris Venditti from the University of Reading, said in a statement.
“The image of T. rex with its fierce jaws has helped it become the most iconic of dinosaurs, but our research shows its bite was relatively unremarkable. Bite force was not what gave T. rex its evolutionary advantage,” Manabu Sakamoto, co-author of the study, explained.
Instead, the T. rex’s status as top dog may simply be a consequence of its size.
“Large predators like T. rex could generate enough bite force to kill its prey and crush bone just by being large, not because they had a disproportionately powerful bite” Sakamoto added.
The researchers came to this conclusion after analyzing the bite force of 434 species (extinct and extant) of animals. Their goal was to find out whether or not animals evolve exceptionally powerful bite forces in relatively short periods of time as a response to dietary changes.
The case of the Galapagos ground finch seems to be an exception to the rule. For the most part, bite force increases slowly and in proportion to body size, as it did with the T. rex. But the researchers noticed another trend, which seems to occur much more frequently – a dramatic reduction in bite force. This is what happened to modern humans, who lost biting power while continuing to grow in size.
"An evolutionary trade-off with increasing brain size in humans may be the reason that our bite power is pretty pathetic," said Sakamoto. "Once we learned to cook food, bite power became even less important."
T. Rex versus finch. University of Reading