INVESTIGADORES
SALGADO Leonardo
congresos y reuniones científicas
Título:
Extreme postcranial pneumaticity in derived sauropod dinosaurs from the Upper Cretaceous of Argentina
Autor/es:
CERDA, I.A.; SALGADO, L.; POWELL, J.E.
Lugar:
Buenos Aires
Reunión:
Jornada; Jornadas Argentina de Paleontología de Vertebrados; 2012
Institución organizadora:
Comisión Ad Hc
Resumen:
Birds are
the only extant group of vertebrates that possesses a pneumatic postcranial
skeleton, which results from invasion of bone by extensions (diverticula) from
the lung and air-sac system. The osteological correlates of these avian airsac
diverticula have been characterized, and postcranial skeletal pneumaticity
(PSP) has been reported in numerous extinct archosaurs including pterosaurs and
non-avian theropods. In sauropod dinosaurs, the pattern of PSP in the axial
skeleton has been interpreted as evidence for an avian-like air sac system in
this group. Here we report a case of extreme PSP in a group of small-bodied,
armored titanosaurian sauropods from the Upper Cretaceous of South America.
Based on osteological data, we corroborate pneumatic features in the pelvic
girdle of this group of sauropod dinosaurs and report an extensive invasion of
pneumatic diverticula along the vertebral column, reaching the distal portion
of the tail. Also, we provide the first evidence of pneumaticity in the
scapular girdle for a sauropodomorph dinosaur. The strict correlation between
specific air sacs and the axial elements that they pneumatize in extant birds
allow to infer the presence of an avian-like clavicular air sac in sauropod
dinosaurs. Our study also reveals that the extreme PSP in archosaurs is not
restricted to pterosaurs and theropod dinosaurs. The PSP appears to be related
to the development of a heterogeneous respiratory system, which possibly
allowed a more efficient, flow-through ventilation of the pulmonary apparatus.