There is a great wealth of information that indicates the staple diet of Spinosaurus was fish. Here we will take a more in-depth look at this evidence.
|A picture of Spinosaurus drawn by the talented young artist Sam Lippincott.|
2. SENSORY ORGANS ON THE TIP OF THE SNOUT: Along with the high placement of the nostrils, Spinosaurus also had a number of small sensory organs at the front of the snout, revealed by CT scans. These greatly resemble those of the crocodile, who uses them to sense where prey is by "seeing" tiny movements in the water. Thus, a crocodile can attack its prey without ever seeing them with their eyes. Spinosaurus appears to have been able to do much the same thing, making its hunting method of choice quite obviously effective, given its immense size.
3. ISOTOPIC EVIDENCE: A study of the isotopes in the skull of a Spinosaurus specimen revealed something quite interesting. Spinosaurus shares a great deal of isotopic overlap with crocodiles, fairly aquatic animals. By contrast, other carnivorous dinosaurs like Tyrannosaurus have very different isotopic readings, indicating a terrestrial lifestyle. Given the great deal of overlap possessed by Spinosaurus and crocodiles, it appears that Spinosaurus spent much of its life like a crocodile; semi-submerged in rivers and streams.
4. THE TEETH TELL THE TALE: Spinosaurus, unlike most other carnivorous dinosaurs like Tyrannosaurus, Allosaurus, or the famous Velociraptor, possess conical, round teeth. These other carnivores possess thin, blade-like teeth, made for slicing, crushing or tearing into other animals. Spinosaurus has teeth much like a crocodile; round and conical. These teeth are made for gripping and making sure that an animal does not escape.
5. THE TEETH TELL THE TALE....AGAIN: Yet again, we come to the issue of teeth, and this is one of the most damning pieces of evidence of all. During the time that Spinosaurus lived in North Africa, another inhabitant of these streams and rivers was a saw-toothed fish called Onchopristis. Two fossils involving Onchopristis have been discovered in conjunction with the remains of Spinosaurus. One was the skull of a Spinosaurus; imbedded in one of the tooth sockets was a vertebrae from an Onchopristis. The other discovery was the barb of an Onchopristis embedded in the jaw of the Spinosaurus.
6. PLUS: We only ever seem to find Spinosaurus in shallow aquatic environments, where fishy prey would be abundant.
All in all, it seems like an inevitable conclusion to draw that Spinosaurus was, in fact, a piscivore, at least much of the time. A fascinating example of the crazy turns evolution can take.