✗ The myth everyone repeats
Dinosaurs were sluggish, ectothermic reptiles like modern lizards, incapable of sustained activity or speed.
✓ What is actually true
Evidence from bone microstructure (rapid growth lines), metabolic indicators (bone cortex density), fossil trackways, and biomechanical models suggests many dinosaurs were active, rapid growers with elevated metabolic rates consistent with endothermy or mesothermy. Theropods like Deinonychus show adaptations for sustained activity, and many could achieve running speeds of 40-60 km/h. The metabolic requirements of large predators and the success of dinosaurs in diverse climates indicate they were not passive ectotherms.
Reception
The receipts 3 sources