 Methods

The methods used to arrive at the numbers in this list include neuron count by isotropic fractionator, optical fractionator or estimation based on correlations observed between number of cortical neurons and brain mass within closely related taxa.Isotropic fractionation is often considered more straightforward and reliable than optical fractionation which may yield both overestimates and underestimates.Estimation based on brain mass and taxon is to be considered the least reliable method.