Sigilmassasaurus Facts
| Diet | Piscivore |
| Height | 4m |
| Length | 15m |
| Weight | 7 tonnes |
| Environment | Water |
| Era | Cretaceous |
| Period | Late Cretaceous |
| Type | Theropod |
| Location | Morocco, North Africa |

| Diet | Piscivore |
| Height | 4m |
| Length | 15m |
| Weight | 7 tonnes |
| Environment | Water |
| Era | Cretaceous |
| Period | Late Cretaceous |
| Type | Theropod |
| Location | Morocco, North Africa |
Sigilmassasaurus is one of palaeontology's most controversial theropod dinosaurs, living between 100 and 94 million years ago during the Late Cretaceous Period in what is now Morocco. Named in 1996 by Canadian palaeontologist Dale Russell, this massive predator has sparked heated scientific debate about whether it represents a distinct species or simply represents fossil material from the famous Spinosaurus aegyptiacus.
Based on the fragmentary remains discovered in Morocco's Kem Kem Beds, Sigilmassasaurus would have been an enormous semi-aquatic theropod, estimated to reach lengths of up to 15 metres and weighing around 7 tonnes. Like other members of its group, it possessed an elongated skull filled with conical teeth perfectly adapted for catching fish, along with powerful claws for grasping slippery prey.
The creature's lifestyle was intimately connected to ancient river systems that flowed through North Africa during the Cretaceous Period. Its diet consisted primarily of large fish, though it likely supplemented this with other aquatic animals and possibly carrion. The theropod's semi-aquatic adaptations would have made it equally at home hunting in shallow waters or along riverbanks.
The ongoing scientific controversy surrounding Sigilmassasaurus highlights the challenges palaeontologists face when working with incomplete fossil material. Whether it proves to be a distinct species or becomes fully synonymous with Spinosaurus, it remains an important piece in understanding the diversity of giant predatory theropods that once dominated Africa's ancient waterways.
Sigilmassasaurus possessed an elongated, crocodile-like skull filled with straight, conical teeth ideal for gripping fish. Its most distinctive feature was likely a tall sail or ridge along its back, supported by extremely long neural spines extending from the vertebrae.
Sigilmassasaurus spent much of its time in and around water, using its powerful jaws to snatch large fish from rivers and lakes. It likely waded through shallow waters like a giant heron, though it was capable of swimming when pursuing prey into deeper areas.
Sigilmassasaurus was first described by Dale Russell in 1996. The original fossils were discovered at Kem Kem Beds, Morocco.