NEUROANATOMY OF PSEUDOSEISURA CURSOR, A FOSSIL FURNARIIDAE (AVES, PASSERIFORMES) FROM THE PLEISTOCENE OF ARGENTINA

DEMMEL FERREIRA, MARÍA MANUELA; DEGRANGE, FEDERICO JAVIER

Córdoba

Congreso; 33as JORNADAS ARGENTINAS DE PALEONTOLOGÍA DE VERTEBRADOS; 2019

Passeriformes is the most diverse group of birds. The information published on Passeriformes brain is scare, especially when it comes to fossil specimens. Pseudoseisura cursor is a fossil species of passeriform from the Ensenadan (Early–Middle Pleistocene) of Vicente López, Buenos Aires province, Argentina. This extinct species of the basal family Furnariidae, is considered to be the sister taxon of the living species P. lophotes, P. cristata and P. gutturalis. In the absence of nondestructive techniques such as CT scanning and 3D modelling that allows studying the endocranium and the endocast without altering the fossil, the preservation of natural endocasts can bring key information regarding ecological, phylogenetical and evolutionary aspects of birds. A description of the morphology of the natural endocast of the holotype (MLP 69-XI-14-1) is resented. The endocast correspond to an airencephalic type of brain. Although the hemispheres are partiallyvisible, it can be noticed that the telencephalon is barely longer than wider (telencephalic length/width= 1.05). The fissura interhemispherica is well marked, wide and deep. The eminentia sagittalis (wulst) appears to be well developed rostrocaudally and the vallecula is hardly noticeable. The cerebellum is short and wide (cerebellar length/width= 0.7) and the contact with the telencephalon has a slightly “U” shape. No cerebellar folds are discernible. The information of the features and characteristics of the endocast of Pseudoseisura cursor will contribute to shed light on the evolutionary success of the most diverse group of birds.