How these prehistoric animals compare
Giganotosaurus and Spinosaurus were giant theropods of the early Late Cretaceous, one from South America and one from North Africa, from two different branches of the theropod family tree.
Two continents once linked by Gondwana
Both animals lived in the Cenomanian-age part of the Cretaceous, when South America and Africa had already begun to separate but still shared many kinds of animals. Giganotosaurus is known from Argentina, Spinosaurus from Egypt and Morocco. Living in a similar time range does not mean they met; they come from different regions and habitats.
A carcharodontosaurid and a spinosaurid
Giganotosaurus belongs to Carcharodontosauridae, a group of large predators with blade-like teeth. Spinosaurus belongs to Spinosauridae, a group with long snouts and conical teeth that is usually linked to fish-eating habits. The skulls reflect these different feeding styles more clearly than any size ranking.
What fossils can and cannot say
Neither animal is known from a complete skeleton. Size estimates for each depend on comparisons with better-known relatives, and they change as new specimens and methods appear. Use the ranges and caveats on the individual field notes instead of treating one number as a final answer.
Sources and specimen context: Giganotosaurus references · Spinosaurus references · Geological timeline
