Why birds never grew to the size of dinosaurs

Birds have retained many of the adaptations that allowed the dinosaurs to evolve to enormous sizes, yet they themselves are dwarfed by today's largest mammals. This video considers what has prevented birds from growing to megafaunal magnitudes. Art by: https://x.com/JoschuaKnuppe https://x.com/astrapionte https://uchytel.com/ https://nixillustration.com/ https://x.com/HodariNundu Music: Dane Meditation 3 by https://teknoaxe.com/ Full list of sources and creative commons imagery to come very shortly