American researchers say they have uncovered a mathematical mistake made by the dinosaur boffinry community, meaning that the weight of live dinos has long been massively overestimated. In a development with devastating consequences for various much-fancied works of fiction, it now appears that in fact the dinosaurs were significantly slenderer than had been thought.
"Paleontologists have for 25 years used a published statistical model to estimate body weight of giant dinosaurs. By re-examining data in the original reference sample, we show that the statistical model is seriously flawed," says Gary Packard of Colorado State University.
According to Packard and his fellow dino-heft experts, the Apatosaurus louisae, for instance - one of the largest of the dinos - was actually far more svelte than had been thought, its weight having been overestimated by no less than 20 tonnes. The Giraffatitan (aka Brachiosaurus) was actually 16 tonnes less portly than formerly estimated.
Packard and his fellow boffins worked from the same information regarding dinosaur bone measurements as previous scientists, but rather than using back-transformation from logarithmic form - which of course any fule kno is not what you do when estimating lizard body mass from bone measurements, tchoh - they instead used equations fitted by nonlinear regression.
In support of their calculations, the dino revisionists point out that their method, applied to bones from an actual elephant, suggested that the elephant should weigh 5.9 tonnes, which is what it actually did weigh. The old school back-transformation-from-logs method, on the other hand, gave an unflatteringly porky picture, suggesting that the experimental dumbo was actually several tonnes heavier than it really was.
In other words, the traditional image of lardy earth-shaking dinosaurs as popularised in Jurassic Park, The Lost World etc etc is deeply flawed. In fact, the mighty lizards of old were (comparatively) slender, dainty and light on their feet.
The scholarly paper Allometric equations for predicting body mass of dinosaurs is published in the (subscription) Journal of Zoology. ®