Spinosaurus: The Mighty Semi-Aquatic Dinosaur
Discovery and Identification
In 1915, German paleontologist Ernst Stromer von Reichenbach described a bizarre dinosaur fossil from Egypt, which he named Spinosaurus aegyptiacus, meaning “Egyptian spine lizard.” The fossil included vertebrae and a skull piece, but Stromer’s work was cut short by the rise of the Nazi regime and the destruction of the Spinosaurus remains in an Allied air strike.
In 2008, paleontologist Nizar Ibrahim traveled to the Sahara in search of African dinosaur fossils. A local fossil hunter showed him a blade-shaped bone that resembled a Spinosaurus spine. Ibrahim brought the fossil back to Morocco and later discovered that the Natural History Museum of Milan had acquired a partial Spinosaurus skeleton.
Ibrahim and his colleagues tracked down the source of the bones to a cliffside cave in the Kem Kem fossil beds of Morocco. Further excavations revealed more spines and other Spinosaurus bones, confirming that this specimen belonged to the same species described by Stromer over a century earlier.
Physical Characteristics and Adaptations
Spinosaurus was an incredibly large dinosaur, measuring up to 50 feet in length and exceeding the size of Tyrannosaurus rex by 9 feet. Its most distinctive feature was its long, sail-like spines on its back vertebrae, which could have reached heights of 6.5 feet.
Spinosaurus also had a number of adaptations that suggest it was semi-aquatic. Its long, narrow snout and nostrils positioned mid-skull allowed it to submerge its head while hunting. It also had neurovascular slits, similar to those found in crocodiles, which may have helped it sense prey underwater.
Spinosaurus had a long neck like a heron or a stork, and its powerful, clawed arms were well-suited for catching and eating fish. Its pelvis was small but attached to powerful, short legs, similar to the ancient ancestors of whales. Its big feet had flat claws, which may have been useful for paddling.
Aquatic Lifestyle
Spinosaurus’s unique adaptations support the theory that it spent a significant amount of time in water. Its loosely connected tail bones could have allowed it to propel itself forward like a fish, and its densely packed bones resemble those of a penguin.
Previous oxygen isotope analysis indicated that Spinosaurus was a pescatarian, primarily feeding on fish. Its conical teeth and powerful claws would have been effective for catching and consuming its aquatic prey.
The Function of the Sail
The function of Spinosaurus’s sail-like spines is still a mystery. Some researchers suggest that it may have been used for display purposes, signaling to other animals about its size and age. Others propose that it may have been used as a thermoregulatory device, helping to absorb heat from the sun.
Significance and Impact
The discovery of Spinosaurus has revolutionized our understanding of dinosaur evolution and behavior. It challenges the traditional view of dinosaurs as exclusively land-dwelling animals and suggests that some species may have adapted to a semi-aquatic lifestyle.
Spinosaurus’s unique adaptations have sparked debate and further research into the evolution of aquatic reptiles and the diversity of dinosaur behavior. It serves as a reminder of the incredible plasticity and adaptability of life on Earth.
National Geographic Exhibition and Documentary
An exhibition entitled “Spinosaurus: Lost Giant of the Cretaceous” is currently on display at the National Geographic Museum in Washington, D.C. The exhibition features the digital model, 3D printed skeleton, and fleshed-out rendering of Spinosaurus aegyptiacus.
National Geographic and NOVA will also air a special documentary about Spinosaurus on PBS on November 5th at 9 pm. The documentary will explore the scientific discoveries and the significance of this extraordinary dinosaur.
