NOTES ON THE AXIAL SKELETON OF BONITASAURA SALGADOI (DINOSAURIA -SAUROPODA): IMPLICATIONS FOR TITANOSAUR VERTEBRAL ANATOMY

PABLO A. GALLINA

ANAIS DA ACADEMIA BRASILEIRA DE CIENCIAS.

ACAD BRASILEIRA DE CIENCIAS

Lugar: Río de Janeiro; Año: 2011 p. 235 - 245

0001-3765

Sauropod axial anatomy has shown decisive implications for both in morphological features and phylogenetic analyses. Spatial arrangement of zygapophyses and rib articulations, as well as their complex laminar development, help to recognize the relative position of isolated vertebral elements. The presence of anterior, mid and posterior elements along the cervical, dorsal and caudal series in Bonitasaura salgadoi allows the analysis of several anatomical characteristics. These include the pattern of neurocentral closure with unfused, partially fused and completely fused elements in a peculiar temporal sequence, as well as several neural spine modifications and the laminar arrangement. The variations in neural spine morphology include a lateral expansion of the distal tip in cervico-dorsal region, different lateral constituents of these lateral expansions, and a markedly deviation in cranio-caudal spine angulations. The spinal inclination allows the division in three well recognizable vertebral regions separated by two landmarks which adds support in the determination of an accurate vertebral position for isolated elements. Finally, an analysis of the vertebral laminae reveals the importance of examining vertebral series in order to recognize laminar homologies and development series. In this way two vertebral laminae are analyzed.