Neuroanatomy of Pseudoseisura cursor, a fossil Furnariidae (Aves, Passeriformes) from the Pleistocene of Argentina

DEGRANGE, F.J.; DEMMEL FERREIRA, M.M.

Córdoba

Congreso; 33.as Jornadas Argentinas de Paleontología de Vertebrados; 2019

Passeriformes is the most diverse group of birds. The informationpublished on Passeriformes brain is scare, especially when it comes to fossilspecimens. Pseudoseisura cursor is a fossilspecies of passeriform from the Ensenadan (early-middle Pleistocene) of VicenteLópez, Buenos Aires Province, Argentina. This extinct species of the basalfamily Furnariidae, is considered to be the sister taxon of the living species P. lophotes, P. cristata and P. gutturalis.In the absence of non-destructive techniques such as CT scanning and 3Dmodelling that allows to study the endocranium and the endocast withoutaltering the fossil, the preservation of natural endocasts can bring keyinformation regarding ecological, phylogenetical and evolutionary aspects ofbirds. A description of the morphology of the natural endocast of the holotype(MLP 69-XI-14-1) is presented. The endocast correspond to an airencephalic typeof brain. Although the hemispheres are partially visible, it can be noticedthat the telencephalon is barely longer than wider (telencephalic length/width = 1.05). The fissurainterhemispherica is well marked, wide and deep. The eminentia sagittalis(wulst) appears to be well developed rostrocaudally and the vallecula is hardlynoticeable. The cerebellum is short and wide (cerebellar length/width = 0.7)and the contact with the telencephalon has a slightly ?U? shape. No cerebellarfolds are discernible. The information of the features and characteristics of the endocast of Pseudoseisura cursor will contribute to shedlight on the evolutionary success of the most diverse group of birds.