(Spine bearing lizard).
Named By: K. Remes, F. Ortega, I. Fierro, U. Joger, R. Kosma & J. N. M. Ferrer - 2009.
Classification: Chordata, Reptilia, Dinosauria, Saurischia, Sauropoda.
Species: S. nigerensis (type).
Size: About 13 meters long.
Known locations: Niger, Agadez - Irhazer Group.
Time period: Middle Jurassic, possibly up to Oxfordian of the late Jurassic. See main text for details.
Fossil representation: Two almost complete individuals.
from being one of the best preserved Jurassic era sauropods
Africa, the features that really made people sit up and pay attention
about Spinophorosaurus are the spiked osteoderms.
Only a few of these
were found, but the researchers involved with piecing
Spinophorosaurus back together have come to the
conclusion that these
spikes most probably formed a thagomizer-like arrangement upon the end
of the tail, similar to the thagomizers of some stegosaurid
such as Stegosaurus
Since the spikes of
Spinophorosaurus were modified osteoderms, they
did not attach
directly to the skeleton, but instead were held in place by the skin
and underlying soft tissues.
Unfortunately at the time of the description, the age of the Spinophorosaurus could not be narrowed down to be any greater than some point between 175 to 161 million years ago. This time period would cover from the latest early Jurassic, the entire middle Jurassic as well as part of the first stage of the late Jurassic, the Oxfordian. Further remains, as well as increased future study and understanding of the fossil localities may one day yield a more refined age estimate.
Spinophorosaurus however probably was not unique nor was it the first sauropod dinosaur to be discovered with a weapon on its tail. During the later stages of the middle Jurassic, a genus named Shunosaurus was roaming around what is now China, and these sauropods had spiked clubs upon the end of their tails. Interestingly, another genus of sauropod from the lower middle Jurassic of China named Nebulasaurus has been noted as having a very similar braincase to Spinophorosaurus. Unfortunately Nebulasaurus is still too incomplete for us to know if it too had a weaponised tail, but a picture seems to be slowly emerging of middle Jurassic sauropods across Africa and Asia that were far from defenceless from potential predators such as theropod dinosaurs.
A new basal sauropod dinosaur from the Middle Jurassic of Niger and the early evolution of sauropoda - PLoS ONE 4 (9) - K. Remes, F. Ortega, I. Fierro, U. Joger, R. Kosma & J. N. M. Ferrer - 2009.