Comparative brain morphology of Neotropical parrots (Aves, Psittaciformes) inferred from virtual 3D endocasts.

CARRIL, J.; TAMBUSSI, C; DEGRANGE, F.; BENITEZ SALDIVAR MARÍA J.,; PICASSO M.B.J.

JOURNAL OF ANATOMY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2015

0021-8782

Psittaciformes are a very diverse group of non-passerine birds, with advanced cognitive abilities and highlydeveloped locomotor and feeding behaviours. Using computed tomography and three-dimensional (3D)visualization software, the endocasts of 14 extant Neotropical parrots were reconstructed, with the aim ofanalysing, comparing and exploring the morphology of the brain within the clade. A 3D geomorphometricanalysis was performed, and the encephalization quotient (EQ) was calculated. Brain morphology characterstates were traced onto a Psittaciformes tree in order to facilitate interpretation of morphological traits in aphylogenetic context. Our results indicate that: (i) there are two conspicuously distinct brain morphologies, oneconsidered walnut type (quadrangular and wider than long) and the other rounded (narrower and rostrallytapered); (ii) Psittaciformes possess a noticeable notch between hemisphaeria that divides the bulbusolfactorius; (iii) the plesiomorphic and most frequently observed characteristics of Neotropical parrots are arostrally tapered telencephalon in dorsal view, distinctly enlarged dorsal expansion of the eminentia sagittalisand conspicuous fissura mediana; (iv) there is a positive correlation between body mass and brain volume; (v)psittacids are characterized by high EQ values that suggest high brain volumes in relation to their body masses;and (vi) the endocranial morphology of the Psittaciformes as a whole is distinctive relative to other birds. Thisnew knowledge of brain morphology offers much potential for further insight in paleoneurological,phylogenetic and evolutionary studies.