Back to Search Start Over

How pneumatic were the presacral vertebrae of dicraeosaurid (Sauropoda: Diplodocoidea) dinosaurs?

Authors :
Windholz, Guillermo J
Carballido, José L
Coria, Rodolfo A
Zurriaguz, Virginia L
Rauhut, Oliver W M
Source :
Biological Journal of the Linnean Society; Jan2023, Vol. 138 Issue 1, p103-120, 18p
Publication Year :
2023

Abstract

Skeletal pneumaticity implies bone invasion via air sacs that are diverticula of the respiratory system. Among extant vertebrates, this feature is found only in birds, and in extinct taxa it occurs in saurischian dinosaurs and pterosaurs. The sauropod axial skeleton is characterized by having a complex architecture of laminae and fossae that have usually been related to some degree of pneumaticity. We examined the external anatomy of the presacral vertebrae of two dicraeosaurid sauropods holotype specimens, Amargasaurus cazaui and Brachytrachelopan mesai , and obtained computed tomography scan images from mid- and posterior cervical vertebrae of both specimens and an anterior dorsal vertebra of Brachytrachelopan. In all cases, we recognized a 'procamerate' internal pneumatization pattern, confirming previous hypotheses that dicraeosaurid vertebral pneumaticity is reduced relative to other eusauropod taxa. Thus, pneumatic diverticula were present in Amargasaurus , Brachytrachelopan , Dicraeosaurus , Pilmatueia and, possibly, other dicraeosaurid sauropods, but these diverticula did not invade their presacral vertebrae extensively. Furthermore, we found that the more pneumatic dicraeosaurid taxa, with some exceptions, occupy a basal position within Dicraeosauridae. There is some variability in pneumaticity among dicraeosaurids from Gondwana, with Pilmatueia achieving the highest degree of pneumatization. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00244066
Volume :
138
Issue :
1
Database :
Complementary Index
Journal :
Biological Journal of the Linnean Society
Publication Type :
Academic Journal
Accession number :
160901963
Full Text :
https://doi.org/10.1093/biolinnean/blac131