The initial phylogenetic analysis presented by Remes and colleagues suggested Spinophorosaurus fell among the most basal sauropods known, being only slightly more derived than Vulcanodon, Cetiosaurus, and Tazoudasaurus.
In this position, it would form the sister taxon of Eusauropoda, a clade comprising all more derived sauropods.
The authors conceded that support for this very basal position was weak, and discussed several alternative placements within eusauropods that would explain anatomical similarities with other sauropods from northern Africa and Laurasia.
A similarly basal position outside of Eusauropoda was suggested by several subsequent studies, which placed Spinophorosaurus as the sister taxon of Tazoudasaurus or Volkheimeria.
In a 2013 conference abstract, palaeontologist Pedro Mocho and colleagues re-evaluated the phylogenetic relationships of the genus by incorporating further information from newly prepared bones, arguing that Spinophorosaurus was nested within eusauropods.
According to this analysis, the genus was more derived than Shunosaurus and Barapasaurus and close to Patagosaurus and mamenchisaurids.
A much more derived systematic position within Eusauropoda was also proposed by a 2015 study, which found Spinophorosaurus to be the sister taxon of Nebulasaurus.



 
Cladogram based on Nair and Salisbury, 2012, which supports a basal position of Spinophorosaurus:
 
Cladogram based on Xing and colleagues, 2015, which supports a more derived position within Eusauropoda:
The initial phylogenetic analysis presented by Remes and colleagues suggested Spinophorosaurus fell among the most basal sauropods known, being only slightly more derived than Vulcanodon, Cetiosaurus, and Tazoudasaurus. In this position, it would form the sister taxon of Eusauropoda, a clade comprising all more derived sauropods. The authors conceded that support for this very basal position was weak, and discussed several alternative placements within eusauropods that would explain anatomical similarities with other sauropods from northern Africa and Laurasia. A similarly basal position outside of Eusauropoda was suggested by several subsequent studies, which placed Spinophorosaurus as the sister taxon of Tazoudasaurus or Volkheimeria. In a 2013 conference abstract, palaeontologist Pedro Mocho and colleagues re-evaluated the phylogenetic relationships of the genus by incorporating further information from newly prepared bones, arguing that Spinophorosaurus was nested within eusauropods. According to this analysis, the genus was more derived than Shunosaurus and Barapasaurus and close to Patagosaurus and mamenchisaurids. A much more derived systematic position within Eusauropoda was also proposed by a 2015 study, which found Spinophorosaurus to be the sister taxon of Nebulasaurus.


 
Cladogram based on Nair and Salisbury, 2012, which supports a basal position of Spinophorosaurus:
 
Cladogram based on Xing and colleagues, 2015, which supports a more derived position within Eusauropoda:
Spinophorosaurus