INVESTIGADORES
PAULINA CARABAJAL ariana
congresos y reuniones científicas
Título:
NEW INSIGHTS ON THE DEVELOPMENT OF THE FLOCCULUS ON PSEUDOSUCHIA (ARCHOSAURIA)
Autor/es:
VON BACZKO, M.B.; BARRIOS, F.; DESOJO, J.B.; PAULINA CARABAJAL, A.; BONA, P.
Lugar:
Diamante
Reunión:
Jornada; 29 Jornadas Argentinas de Palentología de Vertebrados; 2015
Institución organizadora:
CICYTTP
Resumen:
The flocculus is a cerebellar structure associated to the occulomotor reflex, which integrates the movement of the neck, eyes and balance organs. Historically, the flocculus has been related to bipedalism and flying capabilities within Archosauria given its great development on birds and pterosaurs, although recently it has been regarded as a centre of gaze stabilization. We present a review on the presence of this structure within the crocodilian lineage Pseudosuchia. The flocculus is distinguishable in several non-crocodylomorph  pseudosuchians, except in the ornithosuchid Riojasuchus because of its poor preservation. Among aetosaurs, is present in Neoaetosauroides and Desmatosuchus as a semisphericalstructure anterior to the semicircular canals. The floccular recess is present in the endocranium of the poposaurids Arizonasaurus, Effigia, and Shuvosaurus, and it is larger than that of the non-crocodylomorph loricatans Batrachotomus and Postosuchus. On the contrary, the flocculus of the mesoesucrocodilian crocodilomorphs is barely noticeable on the nothosuchians (e.g. Simosuchus, Rukwasuchus). On continentalneosuchians (e.g. Crocodylus, Caiman), as well as on marine ones (?Metriorhynchus? westermanni), it is not present. We can conclude that, 1-the development of the flocculus within archosaurs is not strictly related to bipedalism (poposaurids) or flight since it is present in quadrupedalpseudosuchians (aetosaurs, loricatans); 2- the reduction of the flocculus on continental (terrestrial and aquatic) and marine neosuchians and nothosuchians indicates that its development is not associated to any particular environment. The development of the flocculus might be driven by a higher capacity for gaze stabilization, probably not related to a specific habit.