Spinosaurus Debate Explodes: New Evidence Does NOT Show It Was a Deep-Diving Aquatic Monster

Recent headlines claiming fresh evidence has proven Spinosaurus was a deep-diving “aquatic monster” are misleading. The latest rigorous studies continue to support a semi-aquatic wading lifestyle in rivers and shallow coastal waters, not a submarine predator.

A 2022 eLife paper by Paul Sereno and colleagues used CT-based 3D modeling of the most complete Spinosaurus skeleton yet. The results showed the animal was highly buoyant, with a center of mᴀss that made stable underwater swimming difficult. Maximum estimated swimming speed was under 1 m/s — far too slow for effective pursuit diving. Its tail, while useful for propulsion in shallow water, lacked the power and shape seen in dedicated deep divers like penguins or ichthyosaurs.

Additional 2024–2025 studies have further weakened the deep-diving hypothesis. Bone-density arguments once cited as evidence for diving have been shown to be overstated; similar densities occur in large terrestrial animals. New fossils from inland river deposits in Algeria and Niger, hundreds of kilometres from any ancient coastline, confirm Spinosaurus regularly inhabited freshwater environments far from the sea.

Its crocodile-like snout, conical teeth, and raised nostrils were perfectly suited for ambushing fish while standing or wading in shallow water — more like a giant heron than a submarine. No anatomical features (such as specialized diving lungs, flippers, or streamlined body) support sustained deep diving.

The scientific consensus remains clear: Spinosaurus was a versatile, semi-aquatic predator that thrived along rivers and coastlines, occasionally entering brackish water, but it was never a deep-ocean monster. From the Sahara’s ancient waterways, this sail-backed giant continues to reveal a fascinating but thoroughly shallow-water lifestyle.