Estudios paleoneurológicos en marsupiales carnívoros extinguidos de América del Sur: Neuromorfología y Encefalización.

DOZO, MARÍA TERESA

MASTOZOOLOGíA NEOTROPICAL

UNIDAD DE ZOOLOGÍA Y ECOLOGÍA ANIMAL, INSTITUTO ARGENTINO DE INVESTIGACIÓN DE LAS ZONAS ARIDAS, CRICYT, CONICET

Lugar: Mendoza; Año: 1994 vol. 1 p. 5 - 16

0327-9383

The South American marsupials exhibited a great diversity of forms during the major part of the Cenozoic. The marsupials which played the ecological role of terrestrial carnivores are found in the extinct families Borhyaenidae and Thylacosmilidae. Endocranial casts reflecting the brains of Borhyaena tuberata and Thylacosmilus atrox are studied. These endocasts show a well developed neocortex with a complex sulcal pattern. The inferred encephalic complexity is sufficient to include these brains in one of the tree basic neuroanatomical morphologies which characterize living Australian marsupials: the Diprotodonta (exclusive of Macropodidae) type. The relative brain sizes of B. tuberata and T. atrox are large for polyprotodonts, being its encephalization quotients and progression indices the same o slightly above the average values for living diprotodonts. It is proposed here that during the patterns to those found in most living Australian diprotodont marsupials. It is congruent with the high specializations of the Borhyaenoidea during the Tertiary.