Neurons are old. The last common ancestor had some brains for itself, too. Bird brains are much more neuron-dense than mammalian brains. They also lack the lay

Neurons are old. The last common ancestor had some brains for itself, too. Bird brains are much more neuron-dense than mammalian brains. They also lack the layered structure that permeates our cerebral cortex. I wonder if the different structure is what causes the funny head movement seen across bird species.