Comparison of birds and pterosaurs, the two archosaurian flyers, sheds light on adaptation to an aerial lifestyle. The neurological basis of control holds particular interest in that flight demands on sensory integration, equilibrium, and muscular coordination are acute1,2,3,4,5,6,7,8. Here we compare the brain and vestibular apparatus in two pterosaurs based on high-resolution computed tomographic (CT) scans from which we constructed digital endocasts. Although general neural organization resembles birds, pterosaurs had smaller brains relative to body mass than do birds. This difference probably has more to do with phylogeny than flight, in that birds evolved from nonavian theropods that had already established trends for greater encephalization5,9. Orientation of the osseous labyrinth relative to the long axis of the skull was different in these two pterosaur species, suggesting very different head postures and reflecting differing behaviours. Their enlarged semicircular canals reflect a highly refined organ of equilibrium, which is concordant with pterosaurs being visually based, aerial predators. Their enormous cerebellar floccular lobes may suggest neural integration of extensive sensory information from the wing, further enhancing eye- and neck-based reflex mechanisms for stabilizing gaze.
Subscribe to Journal
Get full journal access for 1 year
only $3.90 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
Newton, E. T. On the skull, brain, and auditory organ of a new species of pterosaurian (Scaphognathus purdoni), from the Upper Lias near Whitby Yorkshire. Phil. Trans. R. Soc. Lond. B 179, 503–537 (1888)
Edinger, T. Das Gehirn der Pterosaurier. Z. Anat. Entwicklungsgesch. 82, 105–112 (1927)
Edinger, T. The brain of Pterodactylus. Am. J. Sci. 239, 665–682 (1941)
Jerison, H. J. Evolution of the Brain and Intelligence 482 (Academic, New York, 1973)
Hopson, J. A. in Biology of the Reptilia Vol. 9 Neurology A (eds Gans, C., Northcutt, R. G. & Ulinki, P.) 39–146 (Academic, New York, 1979)
Wellnhofer, P. The Illustrated Encyclopedia of Pterosaurs 192 (Crescent, New York, 1991)
Bennett, S. C. The osteology and functional morphology of the Late Cretaceous pterosaur Pteranodon. Part I. General description of osteology. Palaeontogr. Abt. A 260, 1–112 (2001)
Wharton, D. S. The Evolution of the Avian Brain 343. PhD thesis, Univ. Bristol (2002)
Larsson, H. C. E., Sereno, P. C. & Wilson, J. A. Forebrain enlargement among nonavian theropod dinosaurs. J. Vert. Paleontol. 20, 615–618 (2000)
Brochu, C. A. Progress and future directions in archosaur phylogenetics. J. Paleontol. 75, 1185–1201 (2001)
Kellner, A. W. A. Description of the braincase of two Early Cretaceous pterosaurs (Pterodactyloidea) from Brazil. Am. Mus. Novit. 3175, 1–34 (1996)
Lebedkin, S. Über die Lage des Canalis semicircularis lateralis bei Säugern. Anat. Anz. 58, 447–460 (1924)
Duijm, M. On the head posture of some birds and its relation to some anatomical features. Proc. Koninkl. Nederl. Akad. Wetensch. C 54, 202–211, 260–271 (1951)
Blanks, R. H. I., Curthoys, I. S. & Markham, C. H. Planar relationships of semicircular canals in the cat. Am. J. Physiol. 223, 55–62 (1972)
Erichsen, J. T., Hodos, W., Evinger, C., Bessette, B. B. & Phillips, S. J. Head orientation in pigeons: postural, locomotor and visual determinants. Brain Behav. Evol. 33, 268–278 (1989)
Spoor, F. & Zonneveld, F. Comparative review of the human bony labyrinth. Yearbook Phys. Anthropol. 41, 211–251 (1998)
de Beer, G. R. How animals hold their heads. Proc. Linn. Soc. Lond. 159, 125–139 (1947)
Chatterjee, S. & Templin, R. J. Posture, locomotion and paleoecology of pterosaurs. Geol. Soc. Am. Spec. Pap. (in the press)
Unwin, D. M., Lü, J. & Bakhurina, N. N. On the systematic and stratigraphic significance of pterosaurs from the Lower Cretaceous Yixian Formation (Jehol Group) of Liaoning, China. Mitt. Mus. Naturk. Berlin Geowiss. Reihe 3, 181–206 (2000)
Jones, G. M. & Spells, K. E. A theoretical and comparative study of the functional dependence of the semicircular canal upon its physical dimensions. Proc. R. Soc. Lond. B 157, 403–419 (1963)
Turkewitsch, B. G. Zur Anatomie des Gehörorgans der Vögel (Canales semicirculares). Z. Anat. Entwicklungsgesch. 103, 551–608 (1934)
Spoor, F., Bajpal, S., Hussain, S. T., Kumar, K. & Thewissen, J. G. M. Vestibular evidence for the evolution of aquatic behavior in early cetaceans. Nature 417, 163–166 (2002)
Butler, A. B. & Hodos, W. Comparative Vertebrate Neuroanatomy: Evolution and Adaptation 514 (Wiley-Liss, New York, 1996)
Winship, I. R. & Wylie, D. R. W. Zonal organization of the vestibulocerebellum in pigeons (Columba livia): I. Climbing fiber input to the flocculus. J. Comp. Neurol. 456, 127–139 (2003)
Wellnhofer, P. Die Rhamphorhynchoidea (Pterosauria) der Oberjura-Plattenkalke Süddeutschlands. Teil I. Allgemeine Skelettmorphologie. Palaeontogr. Abt. A 148, 1–33 (1975)
Kellner, A. W. A. & Tomida, Y. Description of a new species of Anhangueridae (Pterodactyloidea) with comments on the pterosaur fauna from the Santana Formation (Aptian-Albian), northeastern Brazil. Nat. Sci. Mus. Monogr. 17, 1–135 (2000)
Tischlinger, H. & Frey, E. Ein Rhamphorhynchus (Pterosauria, Reptilia) mit ungewöhnlicher Flughauterhaltung aus dem Solnhofener Plattenkalk. Archaeopteryx 20, 1–20 (2002)
Hurlburt, G. R. . Relative Brain Size in Recent and Fossil Amniotes: Determination and Interpretation 250. PhD thesis, Univ. Toronto (1996)
Romer, A. S. Osteology of the Reptiles 772 (Univ. Chicago Press, Chicago, 1956)
Proctor, N. S. & Lynch, P. J. Manual of Ornithology 340 (Yale Univ. Press, New Haven, 1993)
D. S. Berman (Carnegie Museum of Natural History) and J. Maisey (American Museum of Natural History) agreed to the loan and preparation of the pterosaur specimens. M. Atanassov assisted with body mass estimates and other morphometrics. Z. Zheng acid-prepared the fossils. M. Colbert, J. Humphries, R. Ketcham, and J. Maisano assisted with the CT scanning, data processing, and web delivery. Figures were drafted by R. Ridgely (Figs 2 and 3a, c) and K. McQuilkin (Fig. 3b, d, e and Fig. 4). We thank G. R. Hurlburt and D. S. Wharton for sharing data in their doctoral dissertations. We thank G. R. Hurlburt, P. M. O'Connor, E. Weber, and D. S. Wharton for fruitful discussion of pterosaurs and neuroscience, and R. J. Templin for providing aerodynamic expertise. The manuscript benefited from comments provided by D. M. Unwin & S. C. Bennett. Funding was provided by NSF grants to L.M.W. and T.R. and by Texas Tech University to S.C.
The authors declare that they have no competing financial interests.
About this article
Cite this article
Witmer, L., Chatterjee, S., Franzosa, J. et al. Neuroanatomy of flying reptiles and implications for flight, posture and behaviour. Nature 425, 950–953 (2003). https://doi.org/10.1038/nature02048
Neuroanatomy of the spinosaurid Irritator challengeri (Dinosauria: Theropoda) indicates potential adaptations for piscivory
Scientific Reports (2020)
Morphology of the endocranial cavities of Campinasuchus dinizi (Crocodyliformes: Baurusuchidae) from the Upper Cretaceous of Brazil
The internal cranial anatomy of Champsosaurus (Choristodera: Champsosauridae): Implications for neurosensory function
Scientific Reports (2020)
Psittacosaurus amitabha, a New Species of Ceratopsian Dinosaur from the Ondai Sayr Locality, Central Mongolia
American Museum Novitates (2019)