The Continuing Debate on Dinosaur Cognition — Tetrapod Zoology

Clearly, much remains to be learnt about the anatomy of dinosaur brains and what that anatomy does, or does not, mean for behaviour and cognition. The notion that we can make simple inferences about cognition based on overall physiology (the ‘endothermic brain hypothesis’) or that brain enlargement and hence behavioural complexity occurred as the consequence of a Mesozoic ‘arms race’ are both, however, so flawed that they should probably be considered wrong, and sections of our new article are devoted to discussing and refuting these ideas (Caspar et al. 2025).

As should be clear by now, this is very much an active area of debate and consideration. It’s difficult not to be intrigued and even excited by claims that Mesozoic dinosaurs possessed “largely unknown neurocognitive functions approaching those seen in birds” (Jensen et al. 2025). But on dinosaur cognition overall, these animals quite probably overlapped with turtles, squamates and crocodylians as well as birds (Caspar et al. 2024, 2025), the great caveat being that our understanding of cognitive traits in so many of these animals remain very much rudimentary. Again, this mustn’t be interpreted to mean that the extinct animals were deficient or poor in performance given what we currently think about learning, complexity and memory in those living animals.

Acknowledgements. I thank Kai Caspar for checking the text and providing useful suggestions and corrections.

For previous Tetrapod Zoology articles on dinosaur brains, biology and connected issues, see…

You can support this blog – and my work in general – at patreon for as little as $1 per month. Do that, and you also get to see behind-the-scenes and in-prep material I’m working on. Huge thanks to everyone who helps. 

Refs – –

Benton, M. J. 2021. The origin of endothermy in synapsids and archosaurs and arms races in the Triassic. Gondwana Research 100, 261-289.

Caspar, K., Gutiérrez-Ibáñez, C., Hady, G., Holtz, T. R., Naish, D. & Hurlburt, G. R. 2025. Endothermy, neuron counts, and other issues: Further remarks on neurocognitive evolution in fossil vertebrates. The Anatomical Record doi.org/10.1002/ar.70113

Caspar, K., Gutiérrez-Ibáñez, C., Ornella, B. C., Carr, T., Colbourne, J., Erb, A., Hady, G., Holtz, T. R., Naish, D., Wylie, D. R. & Hurlburt, G. R. 2024. How smart was T. rex? Testing claims of exceptional cognition in dinosaurs and the application of neuron count estimates in palaeontological research. The Anatomical Record 2024, doi 10.1002/ar.25459.

Herculano-Houzel, S. 2023. Theropod dinosaurs had primate-like numbers of telencephalic neurons. Journal of Comparative Neurology 531, 962-974.

Jensen, T. R., Jacobs, I., Kverková, K., Lalic, L., Polonyiová, A., Stehlík, P., Reber, S. A., & Osvath, M. 2025. T. rex cognition was T. rex-like – A critical outlook on diverging views of the neurocognitive evolution in dinosaurs. The Anatomical Record doi.org/10.1002/ar.70074

Osvath, M., Němec, P., Brusatte, S. L., & Witmer, L. M. 2024. Thought for food: the endothermic brain hypothesis. Trends in Cognitive Sciences 28, 998-1010.