Temporal range: Lower Cretaceous
Amargasaurus was a sauropod from the early Cretaceous period. It grew to 10 meters (33 feet) length, which was relatively small for a sauropod. It was a quadrupedal herbivore with a long, low skull on the end of a long neck, much like its relative Dicraeosaurus.
Features[change | change source]
Amargasaurus had two tall rows of spines on top of its backbone along the neck and back.:174 The function of the spines is not known. They may have operated as a defence from theropod attack from above. Another idea is that they supported a sail-like structure.
The neural spines were bifurcated along their entire length, forming a double row.:174 They were circular in cross section and tapered towards their tips.:174 The tallest spines could be found on the middle part of the neck, where they reached 60 cm on the 8th cervical.:174 On the neck, they were bowed backwards, projecting above the adjacent vertebra.:304 Greatly elongated spines continue along the last two dorsal vertebrae, the hip and foremost tail. However, in these regions the spines were not bifurcated but flared into a paddle-shaped upper end.:1139
References[change | change source]
- Novas, Fernando E. 2009. The age of dinosaurs in South America. Bloomington: Indiana University Press. ISBN 978-0-253-35289-7
- Upchurch P; Barrett P.M, & Dodson P. 2004. Sauropoda. In: Weishampel D.B; Dodson P. & Osmolska H. (eds) The Dinosauria. 2nd ed, Berkeley: University of California Press, 259–322.
- Bailey, Jack Bowman 1997. Neural spine elongation in dinosaurs: sailbacks or buffalo-backs?. Journal of Paleontology 71 (6): 1124–1146.