Study sheds new light on behavior of giant carnivorous dinosaur Spinosaurus

New research from Queen Mary University in London and the University of Maryland has reignited the debate around the behavior of the giant dinosaur Spinosaurus.

Since its discovery in 1915, the biology and behavior of the enormous Spinosaurus has intrigued paleontologists around the world. It has recently been argued that the dinosaur is largely an aquatic predator, using its large tail to swim and actively pursue fish in the water.

The new study, published today in Palaeontologia Electronica, calls into question this recent view of the Spinosaurus, suggesting that while it likely fed on water and could have been swimming, it was not well adapted to the life of an aquatic chasing predator. Instead, it was like a heron or a giant stork (if unable to fly) – catching fish on the shore while taking any other small prey available on land or in the water.

The researchers compared the characteristics of the Spinosaurus with the skulls and skeletons of other dinosaurs and various living and extinct reptiles that lived on land, in water, or both. They found that while there was several pieces of evidence that contradicted the concept of a water chase predator, none contradicted the heron-like wading model, and various sources of evidence actively supported it.

Dr David Hone, Senior Lecturer at Queen Mary and lead author of the project, said: “The biology and ecology of Spinosaurus has concerned paleontologists for decades. Some recent studies suggest that he actively hunted fish in water but while they could swim, they would not have been fast or efficient enough to do so effectively. Our results suggest that the idea of ​​wading is much better supported, although it is slightly less exciting. “

Co-author Tom Holtz, Senior Lecturer in Palaeontology of Vertebrae, University of Maryland, said, “The spinosaurus was a bizarre animal, even by dinosaur standards, and unlike anything alive today, it will therefore always be difficult to understand its ecology. We sought to use what evidence we have to better approach his lifestyle. And what we found did not match the attributes one would expect in a water chase predator like an otter, sea lion, or short-necked plesiosaur. “

One of the main pieces of evidence the researchers found was around the dinosaur’s ability to swim. The spinosaurus has previously been shown to be a less efficient swimmer than a crocodile, but it also has less tail muscles than a crocodile and, due to its size, is said to have significantly more drag in the water.

Dr Hone said: “Crocodiles are excellent in water compared to land animals, but are not very specialized for aquatic life and are not able to actively hunt fish. If the Spinosaurus had less muscle on it. tail, less efficiency and more drag, so it’s hard to see how these dinosaurs could hunt fish in a way crocodiles can’t. “

Dr Holtz added: “We certainly add that the evidence indicates that the Spinosaurus forages partly, if not mainly, in water, probably more than any other large dinosaur. But this is a different claim than a fast swimmer chasing aquatic prey. “Although, as Dr. Hone concludes:” While our study provides us with a clearer picture of the ecology and behavior of Spinosaurus, there are still many questions and details unanswered to consider for future study and we must continue to revisit our ideas as we accumulate more evidence and data on these unique dinosaurs. It won’t be the last word on the biology of these amazing animals. “

Originally found in Egypt, the Spinosaurus is believed to be one of the largest carnivorous dinosaurs to exist, possibly reaching over 15m in length. The earliest known fossils of Spinosaurus were destroyed by Allied bombing raids during World War II, hampering attempts by paleontologists to understand these unusual creatures. Most recently, the dinosaur found fame in the 2001 film Jurassic Park III, where it fights and defeats a Tyrannosaurus rex.