The story of Spinosaurus began in 1912 with a partial skeleton discovered in Egypt. Described by paleontologist Ernst Stromer, the unique specimen, known for its massive sail-like back spines, was tragically destroyed in a WWII bombing raid in 1944. For decades, only Stromer’s detailed drawings remained, leaving one of the largest-ever carnivores a creature of scientific mystery.

A modern skeletal reconstruction, pieced together from fragmentary discoveries that followed the loss of the original fossil.

(“Spinosaurus – 02” by Kabacchi is licensed under CC BY 2.0 .)

In the 21st century, new fossils from Morocco’s Kem Kem Beds revolutionized our understanding of Spinosaurus. A 2014 study revealed unexpectedly short hind limbs, leading to the radical hypothesis that it might have walked on four legs. Then, a 2020 discovery showed it possessed a long, flexible, paddle-like tail, suggesting it was a powerful swimmer unlike any other large theropod.

This 2020 reconstruction features the paddle-like tail, a key piece of evidence that reshaped Spinosaurus as a semi-aquatic hunter.

(“Spinosaurus aegyptiacus” by Gustavo Monroy-Becerril is licensed under CC BY-SA 4.0 .)

The idea of an aquatic Spinosaurus is strongly supported by its anatomy. Its crocodile-like snout and conical teeth were perfect for catching fish. In 2022, a study revealed it had extremely dense bones, similar to modern diving animals like penguins and manatees, which would have helped control buoyancy for hunting underwater. However, this interpretation remains highly contested.

Despite new evidence, major questions remain. Was Spinosaurus an active pursuit predator or a shoreline generalist? How did it move on land? Some models suggest it would have been an unstable swimmer and too buoyant to dive, favoring a wading, heron-like hunting style. Its terrestrial locomotion is also debated, with recent studies leaning toward a slow, bipedal gait rather than walking on all fours.

Was it an active underwater hunter? The lifestyle of Spinosaurus remains one of the most hotly debated topics in paleontology.

(“Spinosaurus by Silvia Pasqualetto @” by RobinGoodfellow_(m) is marked with Public Domain Mark 1.0 .)

From a lost fossil to a paleontological icon, Spinosaurus highlights the dynamic nature of scientific discovery. Each new fossil fragment and technological advance adds another piece to its complex puzzle, forcing scientists to constantly re-evaluate how this magnificent creature lived. The ongoing debates ensure that Spinosaurus will remain a fascinating subject of research for years to come.