Amargasaurus

Genus of reptiles (fossil)

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.

Amargasaurus
Temporal range: Lower Cretaceous
130–125 mya
Scientific classification
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Amargasaurus

Amargasaurus was found in La Amarga, a canyon in Neuquén Province, Argentina.

Features

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Amargasaurus had two tall rows of spines on top of its backbone along the neck and back.[1]: 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.[1]: 174  They were circular in cross section and tapered towards their tips.[1]: 174  The tallest spines could be found on the middle part of the neck, where they reached 60 cm on the 8th cervical.[1]: 174  On the neck, they were bowed backwards, projecting above the adjacent vertebra.[2]: 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.[3]: 1139 

References

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  1. 1.0 1.1 1.2 1.3 Novas, Fernando E. 2009. The age of dinosaurs in South America. Bloomington: Indiana University Press. ISBN 978-0-253-35289-7
  2. 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.
  3. Bailey, Jack Bowman 1997. Neural spine elongation in dinosaurs: sailbacks or buffalo-backs?. Journal of Paleontology 71 (6): 1124–1146. [1]