In Depth
Aside from being one of the best preserved Jurassic era sauropods from 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 dinosaurs such as Stegosaurus and Tuojiangosaurus. 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.
Further Reading
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. – The braincase of the basal sauropod dinosaur Spinophorosaurus and 3D reconstructions of the cranial endocast and inner ear. – PLOS ONE. 7 (1). – F. Knoll, L. M. Witmer, F. Ortega, R. C. Ridgely & D. Schwarz-Wings – A. A. Farke (ed.) – 2012. – Spinophorosaurus (Sauropoda), a new look inside eusauropod evolution. – Abstract Book of the VI International Symposium About Dinosaurs Paleontology and Their Environment. Salas de los Infantes Burgos. pp. 89–90. – P. Mocho, F. Ortega, A. Aberasturi & F. Escaso – 2013. – The specialized tail of Spinophorosaurus nigerensis (Sauropoda. Middle Jurassic) and the osteological limits on its range of motion. – 63rd SVPCA (Symposium for Vertebrate Palaeontology and Comparative Anatomy), At Southampton, England. – D. C. Vidal & F. Ortega – 2015. – Isolated theropod teeth from the Middle Jurassic of Niger and the early dental evolution of Spinosauridae. – Acta Palaeontologica Polonica: 403–415. – A. Serrano-Mart�nez, D. Vidal, L. Sciscio, F. Ortega & F. Knoll – 2015. – Assembling a virtual Spinophorosaurus skeleton: what can it teach us about the evolution of eusauropods?. – VII Jornadas Internaciones sobre Paleontolog�a de Dinosaurios y su Entorno. Salas de los Infantes, Burgos. Burgos. pp. 147–148. – D. Vidal, A. Aberasturi, P. Mocho, F. Ortega & J. L. Sanz – 2016. – New information about the appendicular skeleton of Spinophorosaurus nigerensis (Middle Jurassic, Niger). 16th European Association of Vertebrate Paleontologists Meeting, Caparica (Portugal). – European Association of Vertebrate Palaeontologists. p. 124. – P. Mocho, D. Vidal, A. Aberasturi, R. Kosma & F. Ortega – 2018. – Using 3D geometric morphometrics to estimate missing vertebrae in a Spinophorosaurus dorsal spine (Middle Jurassic, Niger). 16th European Association of Vertebrate Paleontologists Meeting, Caparica (Portugal). – European Association of Vertebrate Palaeontologists. p. 75. – D. Garc�a-Mart�nez, D. Vidal & F. Ortega – 2018. – Cases of pathological bone growth in Isanosaurus and Spinophorosaurus (Sauropoda). – 5th International Palaeontological Congress – Pierre and Marie Curie Campus of Sorbonne University; National Museum of Natural History, Paris, France. – C. Jentgen-Ceschino & K. Stein – 2018. – High browsing skeletal adaptations in Spinophorosaurus reveal an evolutionary innovation in sauropod dinosaurs. – Scientific Reports. 10 (1): 6638. – D. Vidal, P. Mocho, A. Aberasturi, J. L. Sanz & F. Ortega – 2020.
