Spinophorosaurus is known from the Irhazer Shale of Niger, which has been determined to represent the base of the Irhazer Group (based on the presence of red clay that show interbedded sand beds with traces of subaerial exposure and dinosaur footprints), which is stratigraphically below the outcrops of the Tegama Group.
The Irhazer Group was earlier considered Jurassic to earliest Cretaceous in age, as the overlying Tiourarén Formation was once considered to be of Lower Cretaceous age.
Subsequent studies have found the latter formation to be Middle Jurassic to early Late Jurassic.
The stratigraphical and phylogenetic position of Spinophorosaurus (compared with other basal sauropods from around the world) indicates it could be Middle Jurassic (Bajocian–Bathonian) in age.
Since the strata of the Irhazer Group cannot yet be directly dated, it might be as old as Lower Jurassic.
The lower limit is defined by the underlying Agadez Group, which is Upper Triassic in age (based on the presence of Chirotherium trace fossils).

The Spinophorosaurus skeletons were discovered in a massive to finely laminated red siltstone, whose matrix contained some carbonate.
The fossils were recovered from the upper half of this several metres-thick siltstone layer.
The layers there are subhorizontal, bearing minor faults, and commonly contain palaeosoils and carbonate at the top of the unity (about a metre above the level with the skeletons).
Sediments of the Irhazer Group were deposited under conditions that were fluvio-lacustrine (associated with rivers and lakes), during a time when the Iullemmeden Basin was part of a great river-valley system, which was connected with the Proto-Atlantic coast of Gondwana through adjacent basins.

Four theropod teeth were found closely associated with the Spinophorosaurus holotype (by a vertebra, pubis, and in the acetabulum); three had similarities with Megalosauridae and Allosauridae, while the fourth belongs to what may be one of the earliest known members of Spinosauridae.
The fact that the teeth are poorly preserved while the Spinophorosaurus skeleton is well-preserved indicates that the teeth were transported before being buried with the sauropod.
Dinosaur tracks were found some hundred metres away from the Spinophorosaurus site, including a trackway of six footprints from a mid-sized sauropod as well as 120 well-preserved didactyl (two-toed) theropod footprints.
The didactyl tracks were originally thought to have been left by paravian theropods (such as dromaeosaurs or troodontids, which have two weight-bearing toes), but were subsequently interpreted as having been produced by swimming theropods (explaining why one toe did not leave a trace).
Spinophorosaurus is known from the Irhazer Shale of Niger, which has been determined to represent the base of the Irhazer Group (based on the presence of red clay that show interbedded sand beds with traces of subaerial exposure and dinosaur footprints), which is stratigraphically below the outcrops of the Tegama Group. The Irhazer Group was earlier considered Jurassic to earliest Cretaceous in age, as the overlying Tiourarén Formation was once considered to be of Lower Cretaceous age. Subsequent studies have found the latter formation to be Middle Jurassic to early Late Jurassic. The stratigraphical and phylogenetic position of Spinophorosaurus (compared with other basal sauropods from around the world) indicates it could be Middle Jurassic (Bajocian–Bathonian) in age. Since the strata of the Irhazer Group cannot yet be directly dated, it might be as old as Lower Jurassic. The lower limit is defined by the underlying Agadez Group, which is Upper Triassic in age (based on the presence of Chirotherium trace fossils).
The Spinophorosaurus skeletons were discovered in a massive to finely laminated red siltstone, whose matrix contained some carbonate. The fossils were recovered from the upper half of this several metres-thick siltstone layer. The layers there are subhorizontal, bearing minor faults, and commonly contain palaeosoils and carbonate at the top of the unity (about a metre above the level with the skeletons). Sediments of the Irhazer Group were deposited under conditions that were fluvio-lacustrine (associated with rivers and lakes), during a time when the Iullemmeden Basin was part of a great river-valley system, which was connected with the Proto-Atlantic coast of Gondwana through adjacent basins.
Four theropod teeth were found closely associated with the Spinophorosaurus holotype (by a vertebra, pubis, and in the acetabulum); three had similarities with Megalosauridae and Allosauridae, while the fourth belongs to what may be one of the earliest known members of Spinosauridae. The fact that the teeth are poorly preserved while the Spinophorosaurus skeleton is well-preserved indicates that the teeth were transported before being buried with the sauropod. Dinosaur tracks were found some hundred metres away from the Spinophorosaurus site, including a trackway of six footprints from a mid-sized sauropod as well as 120 well-preserved didactyl (two-toed) theropod footprints. The didactyl tracks were originally thought to have been left by paravian theropods (such as dromaeosaurs or troodontids, which have two weight-bearing toes), but were subsequently interpreted as having been produced by swimming theropods (explaining why one toe did not leave a trace).
Spinophorosaurus