Overview
- Researchers from the American Museum of Natural History and Princeton used an energy-and-reproduction model to predict optimal body sizes for vertebrate groups.
- The model, which matches modern mammals, birds and turtles, predicts a modal dinosaur mass near 3 kilograms while the fossil record shows a peak near 180 kilograms.
- The team reports Wednesday that very small dinosaur bones are effectively absent from known fossil sites and argues taphonomic loss alone is unlikely to explain the gap.
- Lead author Stephanie Lechki and co-author Roger Benson propose that small mammals occupied the tiny, resource-limited niches that would have favored mouse-sized dinosaurs.
- If correct, the finding reframes Mesozoic ecology by showing how competition between clades can override energetic optima and it points to targeted fossil searches and ecological tests as the next steps.